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A review on human toxoplasmosis
Abstract
Toxoplasmosis is a worldwide infection caused by the intracellular parasite Toxoplasma gondii. At least a third of the world human population are infected with the parasite, making it one of the most successful parasitic infections. Primary maternal infection may cause health-threatening sequelae for the foetus, or even cause death in uterus. Reactivation of a latent infection in immune deficiency conditions such as AIDS and organ transplantation can cause fatal toxoplasmic encephalitis. Toxoplasmosis is a major cause of retinochoroiditis, especially in individuals with an impaired immune system. Despite the usually 'asymptomatic' nature of the infection, a significant burden imposed by the parasite necessitates the implementation of effective means for the prevention, diagnosis, and management of this disease. Laboratory diagnosis, i.e. PCR and serologic assays, plays the main role in the diagnosis of congenital infection and assists in the confirmatory diagnosis of toxoplasmic encephalitis and ocular toxoplasmosis. Here, we briefly review general aspects of Toxoplasma infection and focus on the diagnostic methods currently used in medical laboratories for the diagnosis of Toxoplasma infection.
... Toxoplasmosis (TS) is a prevalent parasitic infection that affects both humans and animals, caused by Toxoplasma gondii. 1 TS affects around one-third of the humans worldwide. 1 This parasite can infect a wide range of warm-blooded animals; however, it can only undergo sexual reproduction in felids, specifically in cats, which are the definitive hosts. ...
... Toxoplasmosis (TS) is a prevalent parasitic infection that affects both humans and animals, caused by Toxoplasma gondii. 1 TS affects around one-third of the humans worldwide. 1 This parasite can infect a wide range of warm-blooded animals; however, it can only undergo sexual reproduction in felids, specifically in cats, which are the definitive hosts. The prevalence of T. gondii antibodies differs significantly across various regions globally. ...
Background: This study aimed to evaluate the possible effects of Toxoplasma gondii infection on breast cancer through affecting the serum and expression gene level of programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) in breast cancer patients from Thi-qar province, Iraq. Methods: This case-control study was involved 150 patients suffering from breast cancer (BC) who were referring to general hospitals of Thi-Qar province between July to September 2023 and 150 healthy patients (non-BC). Enzyme-linked immunosorbent test (ELISA) kit was used to evaluate the anti-Toxoplasma IgG and the serum level of PD-1 and PDL-1. Furthermore, the expression level of PD-1 and PDL-1 was measured through Real-time PCR. Results: Among 150 breast cancer patients, 71 patients (47.3%) and 25 (16.6%) of healthy subjects exhibited seropositivity for anti-T. gondii IgG antibodies, resepectively. We found that the serum level and the gene expression level of PD-1 and PDL-1 were significantly higher among BC patients seropositive for T. gondii compared with BC patients who were seronegative for T. gondii antibodies (p<0.05). Conclusion: These results indicated that T. gondii may play a role in the occurrence and even progression of cancer probably by elevating levels of PD-1 and PDL-1 genes. However, further studies are required to confirm these findings.
... Toxoplasma gondii is an obligate intracellular parasite that infects virtually all warm-blooded animals, including humans (Tenter et al. 2000). Infection with T. gondii can cause a disease called toxoplasmosis, which can be severe and even fatal in some cases, particularly in neonates and immunocompromised individuals (Saadatnia and Golkar 2012;Wang et al. 2017). Toxoplasmosis is a major public health concern worldwide, with approximately 2 billion people infected (Rahmanian et al. 2020). ...
... The majority of infected people are asymptomatic, but some may experience mild flu-like symptoms. In severe cases, toxoplasmosis can cause a variety of complications, including encephalitis, retinitis, and seizures (Saadatnia and Golkar 2012). Workers occupationally exposed to animals (WOEA), such as animal breeders, hunters, butchers, livestock workers, meatpacking workers, slaughterhouse workers, and veterinary personnel, are at heightened risk of T. gondii infection, particularly if they do not use appropriate personal protective equipment (PPE) (Wright et al. 2008;Odo et al. 2015;Habib and Alshehhi 2021). ...
Toxoplasma gondii, a ubiquitous zoonotic parasite infecting warm-blooded animals, poses a significant health threat to workers with occupational animal exposure (WOEA) due to their frequent contact with potential reservoirs. Existing data on T. gondii seroprevalence in the WOEA exhibits substantial global variation. This systematic review and meta-analysis, adhering to PRISMA guidelines, aimed to quantify the global seroprevalence of T. gondii infection among WOEA over the past five decades (1972–2023). We identified 66 eligible studies through a comprehensive search strategy encompassing English publications, with a total sample size of 15,279. A random-effects model with the Freeman-Tukey transformation in STATA v16.0 accounted for the high heterogeneity observed. We estimated the pooled global seroprevalence of T. gondii infection in WOEA at 41% (95% CI: 36–47%). Subgroup analyses revealed significant variations by gender: males (63%) vs. females (37%) (p < 0.05), occupation: non-livestock workers (54%), livestock workers (47%), slaughterhouse workers (44%), and veterinary personnel (27%) (p < 0.05). Geographic trends showed the highest prevalence in Africa (51%), followed by South America (49%), Europe (47%), Australia (43%), Asia (36%), and North America (23%; p < 0.05). Lower prevalence was observed in high-income (39%) and upper-middle-income (38%) countries compared to lower-middle-income (44%) and low-income (48%) countries (p < 0.05). This analysis underscores the high global seroprevalence of T. gondii in the WOEA, highlighting the need for targeted interventions in this high-risk population.
... KEYWORDS Chronic infection, tissue cyst, Apetala 2 transcription factor, stress-induced differentiation T oxoplasma gondii is a widespread opportunistic protozoan parasite capable of infecting a broad range of warm-blooded hosts, including wild, companion, and domesticated animals. It is a frequent cause of zoonotic infection in humans, and it is estimated that approximately a third of the world's population is chronically infec ted with T. gondii (1,2). Although most cases of infection are associated with mild symptoms in immunocompetent individuals, toxoplasmosis can be life-threatening in immunocompromised individuals (3,4). ...
... The ability of T. gondii to convert into cysts containing bradyzoites within host tissues allows for long-term persistence, transmission to other hosts, and potential reactivation that causes severe disease in immunocompromised individuals (2,43). An in vitro culture system for T. gondii cysts would aid in understanding the basis for recrudescence and possibly identify targets for intervention. ...
Toxoplasma gondii bradyzoites play a critical role in pathology due to their long-term persistence in intermediate hosts and their potential to reactivate, resulting in severe diseases in immunocompromised individuals. Currently, there is no effective treatment for eliminating bradyzoites. Hence, better in vitro models of T. gondii bradyzoite development would facilitate identification of therapeutic targets for bradyzoites. Herein, we characterized a natural isolate of T. gondii, called Tg68, which showed slower in vitro replication of tachyzoites, and permissive bradyzoite development under stress conditions in vitro. Transcriptional analysis revealed constitutive expression in Tg68 tachyzoites of the key regulators of bradyzoite development including BFD1, BFD2, and several AP2 factors. Consistent with this finding, Tg68 tachyzoites expressed high levels of bradyzoite-specific genes including BAG1, ENO1, and LDH2. Moreover, after stress-induced differentiation, Tg68 bradyzoites exhibited gene expression profiles of mature bradyzoites, even at early time points. These data suggest that Tg68 tachyzoites exist in a pre-bradyzoite stage primed to readily develop into mature bradyzoites under stress conditions in vitro. Tg68 presents a novel model for differentiation in vitro that will serve as a useful tool for the investigation of bradyzoite biology and the development of therapeutics.
IMPORTANCE
Toxoplasma gondii is a widespread protozoan that chronically infects ~30% of the world’s population. T. gondii can differentiate between the fast-growing life stage that causes acute infection and the slow-growing stage that persists in the host for extended periods of time. The slow-growing stage cannot be eliminated by the host immune response or currently known antiparasitic drugs. Studies on the slow-growing stage have been limited due to the limitations of in vivo experiments and the challenges of in vitro manipulation. Here, we characterize a natural isolate of T. gondii, which constitutively expresses factors that drive development and that is permissive to convert to the slow-growing stage under stress conditions in vitro. The strain presents a novel in vitro model for studying the chronic phase of toxoplasmosis and identifying new therapeutic treatments for chronic infections.
... The obligate intracellular protozoan parasite Toxoplasma gondii is a prevalent pathogen worldwide [1]. Because significant overt infections are rare, the extent of the actual Toxoplasma infection is mainly estimated based on serological test results. ...
... The risk factors for Toxoplasma seropositivity, including consumption of raw or undercooked meat, frequent contact with soil, older age, and lower CD4+ lymphocyte counts, have been clarified to some extent [1,11,12]. However, some limitations exist in applying these to a special group, such as PLWH, and most studies to date have focused on the risk factors of the seropositive rate. ...
Introduction
Toxoplasma gondii can cause symptomatic toxoplasmosis in immunodeficient hosts, including in people living with human immunodeficiency virus (PLWH), mainly because of the reactivation of latent infection. We assessed the prevalence of toxoplasmosis and its associated risk factors in PLWH in the Asia-Pacific region using data from the TREAT Asia Human Immunodeficiency Virus (HIV) Observational Database (TAHOD) of the International Epidemiology Databases to Evaluate AIDS (IeDEA) Asia-Pacific.
Methods
This study included both retrospective and prospective cases of toxoplasmosis reported between 1997 and 2020. A matched case-control method was employed, where PLWH diagnosed with toxoplasmosis (cases) were each matched to two PLWH without a toxoplasmosis diagnosis (controls) from the same site. Sites without toxoplasmosis were excluded. Risk factors for toxoplasmosis were analyzed using conditional logistic regression.
Results
A total of 269/9576 (2.8%) PLWH were diagnosed with toxoplasmosis in 19 TAHOD sites. Of these, 227 (84%) were reported retrospectively and 42 (16%) were prospective diagnoses after cohort enrollment. At the time of toxoplasmosis diagnosis, the median age was 33 years (interquartile range 28–38), and 80% participants were male, 75% were not on antiretroviral therapy (ART). Excluding 63 out of 269 people without CD4 values, 192 (93.2%) had CD4 ≤200 cells/μL and 162 (78.6%) had CD4 ≤100 cells/μL. By employing 538 matched controls, we found that factors associated with toxoplasmosis included abstaining from ART (odds ratio [OR] 3.62, 95% CI 1.81–7.24), in comparison to receiving nucleoside reverse transcriptase inhibitors plus non-nucleoside reverse transcriptase inhibitors, HIV exposure through injection drug use (OR 2.27, 95% CI 1.15–4.47) as opposed to engaging in heterosexual intercourse and testing positive for hepatitis B virus surface antigen (OR 3.19, 95% CI 1.41–7.21). Toxoplasmosis was less likely with increasing CD4 counts (51–100 cells/μL: OR 0.41, 95% CI 0.18–0.96; 101–200 cells/μL: OR 0.14, 95% CI 0.06–0.34; >200 cells/μL: OR 0.02, 95% CI 0.01–0.06), when compared to CD4 ≤50 cells/μL. Moreover, the use of prophylactic cotrimoxazole was not associated with toxoplasmosis.
Conclusions
Symptomatic toxoplasmosis is rare but still occurs in PLWH in the Asia-Pacific region, especially in the context of delayed diagnosis, causing advanced HIV disease. Immune reconstitution through early diagnosis and ART administration remains a priority in Asian PLWH.
... promised patients, it has serious side effects, like nerve and eye problems and even death [6]. There are usually no obvious clinical symptoms in healthy people, but it can cause serious harm to the fetus or to immunocompromised patients, such as those with acquired immunodeficiency syndrome (AIDS) [7]. In specific, it can cause retinochoroiditis and toxoplasmic encephalitis in people and fetus removal in animals [7]. ...
... There are usually no obvious clinical symptoms in healthy people, but it can cause serious harm to the fetus or to immunocompromised patients, such as those with acquired immunodeficiency syndrome (AIDS) [7]. In specific, it can cause retinochoroiditis and toxoplasmic encephalitis in people and fetus removal in animals [7]. Toxoplasmosis is one of the most causes of death in immunocompromised and dangerous tumor patients but too it can lead to a destroying impact on the livestock's generation and health, especially little household ruminants [8]. ...
Purpose
Infection by the intracellular apicomplexan parasite Toxoplasma gondii has serious clinical consequences in humans and veterinarians around the world. Although about a third of the world’s population is infected with T. gondii, there is still no effective vaccine against this disease. The aim of this study was to develop and evaluate a multimeric vaccine against T. gondii using the proteins calcium-dependent protein kinase (CDPK)1, CDPK2, CDPK3, and CDPK5.
Materials and Methods
Top-ranked major histocompatibility complex (MHC)-I and MHC-II binding as well as shared, immunodominant linear B-cell epitopes were predicted and linked using appropriate linkers. Moreover, the 50S ribosomal protein L7/L12 (adjuvant) was mixed with the construct’s N-terminal to increase the immunogenicity. Then, the vaccine’s physicochemical characteristics, antigenicity, allergenicity, secondary and tertiary structure were predicted.
Results
The finally-engineered chimeric vaccine had a length of 680 amino acids with a molecular weight of 74.66 kDa. Analyses of immunogenicity, allergenicity, and multiple physiochemical parameters indicated that the constructed vaccine candidate was soluble, non-allergenic, and immunogenic, making it compatible with humans and hence, a potentially viable and safe vaccine candidate against T. gondii parasite.
Conclusion
In silico, the vaccine construct was able to trigger primary immune responses. However, further laboratory studies are needed to confirm its effectiveness and safety.
... Entretanto, quando sintomática, pode se relacionar a quadros de linfadenite, coriorretinite e miocardite (Saadatnia; Golkar; 2012). Referente a sintomatologia da doença, em casos de pacientes imunocompetentes a doença apresenta-se em forma benigna e pode passar de forma despercebida(Saadatnia;Golkar;. Entretanto, quando sintomática, pode se assemelhar a sintomas gripais, como febre, linfadenopatia, apatia, mal-estar e outros. ...
... Entretanto, quando sintomática, pode se relacionar a quadros de linfadenite, coriorretinite e miocardite (Saadatnia; Golkar; 2012). Referente a sintomatologia da doença, em casos de pacientes imunocompetentes a doença apresenta-se em forma benigna e pode passar de forma despercebida(Saadatnia;Golkar;. Entretanto, quando sintomática, pode se assemelhar a sintomas gripais, como febre, linfadenopatia, apatia, mal-estar e outros. ...
Todos os capítulos foram desenvolvidos por acadêmicos e acadêmicas
do V semestre da formação médica, sem a pretensão de tornarem-se grandes
referências teóricas acerca dos temas que tratam. Para além, os objetivos que
guiaram suas elaborações envolveram práticas pedagógicas ligadas à pesquisa
por meio da articulação de temas relativos à infectologia e outros, como: edu-
cação em saúde, políticas públicas e desafios globais. Nesse sentido, buscamos
estimular movimentos que desencadeassem práticas de reflexão e escrita, con-
sideradas, em muitos contextos, um desafio.
... T. gondii is a widespread opportunist parasite that is estimated to infect one-third of the human population worldwide (Weiss and Dubey, 2009). It causes toxoplasmosis which is important in congenital infection and in immunosuppressed reactivation (Desmonts and Couvreur, 1974;Leser et al., 2003) as in HIV/AIDS (Saadatnia and Golkar, 2012). In healthy people it is associated with ocular pathologies (Roberts et al., 2001). ...
... The aging process leads to the losing of function in most systems (e.g., immunological system), and T. gondii reactivation becomes potential in this period (Gardner and Remington, 1978a,b). In this context, a competent immune system is fundamental to avoid T. gondii reactivation (Saadatnia and Golkar, 2012). ...
Exercise Physiology, a section of the journal Frontiers in Physiology Physical exercise has been implicated in several immunophysiological improvements, particularly during the aging process, when an immunocompromised status could be established. Toxoplasma gondii is a protozoan parasite that causes a widespread opportunistic infection, which may present severe consequences, mainly to the fetus and immunocompromised patients. It is estimated that one-third of the human population worldwide has been infected by this parasite, being the reactivation during immunesenescence an unexplored public health issue. The major purpose of the present study was to observe the immunophysiological differences between exercised vs. sedentary C57BL/6 male mice that have been experimentally infected by T. gondii. In the first set of experiments, the animals were infected after exercising and three groups were set up: experimental groups-infected sedentary (IS, n = 6); infected exercised (IEx, n = 6) and control group-non-infected sedentary (NIS, n = 6). When stimulated in vitro by T. gondii-soluble tachyzoite antigen, it was found that splenocytes from exercised group produced higher levels of IFN-γ, as well as of IFN-γ/IL-10 ratios in comparison with splenocytes from sedentary animals (P < 0.001). However, it was not found significant differences concerning quantification of T. gondii genomic DNA by qRT-PCR and immunohistochemistry analysis in brain cysts from both group of animals (P > 0.05). In order to further investigate the consequences of these data for the host, a second set of experiments was performed, when the animals were infected before exercising and four groups of animals were established for comparison purpose, as follows: experimental groups-infected sedentary (IS, n = 7); infected exercised (IEx, n = 6) and control groups-non-infected sedentary (NIS, n = 6) and non-infected exercised (NIEx, n = 6). It was found significant differences in the survival rates of the exercised group the animals, as they survived longer than sedentary groups (P = 0.0005). In both sets of experiments, mice have been submitted to moderate exercises: aerobic Bortolini et al. Physical Exercise for Toxoplasma gondii Infection (14 m/min; 3 x/week) and strength (60-80% of one maximum repetition; 2 x/week). Overall, our findings are showing that the aerobic and strength exercises are able to modulate immune response against T. gondii infection, being these immunological features beneficial to the host.
... The bradyzoite form is resistant to gastric juices and is considered the most critical form in the T. gondii life cycle [11]. While generally patients typically experience only mild symptoms such as cold-like symptoms [12], the elderly, children and immunocompromised individuals may develop severe symptoms such as neurotoxoplasmosis, ocular toxoplasmosis, and even death [13,14]. Especially, the infected pregnant patients and newborns has symptoms abortion, stillbirth and miscarriage [3,15]. ...
Background
Toxoplasma gondii, an intracellular parasite, is a significant cause of zoonotic disease, with an estimated one-third of the world’s human population believed to be infected. T. gondii is transmitted to humans through the consumption of contaminated water, soil, vegetables, fruits, shellfish or undercooked meat, and can also be passed from human to human through vertical transmission, transplants and blood transfusion. While T. gondii infection typically manifests mild symptoms such as colds among immunocompetent individuals, it can prove lethal for those with weakened immune systems.
Methods
To summarize the diagnostic methods for Toxoplasma gondii infection, we performed a literature search on PubMed from 1948 to 2023 using the keywords “T. gondii serological diagnosis” or “T. gondii molecular diagnosis”.
Results
Rapid and accurate diagnosis of T. gondii infection is imperative. Although a diagnostic kit is currently commercially available, there are a number of disadvantages to the validation principles applied to each diagnostic kit. Consequently, multiple diagnostic methods are concurrently employed to offset these limitations. Serological methods for diagnosing T. gondii infection include the Dye Test (DT), Agglutination Test (AT), Modified Agglutination Test (MAT), Latex Agglutination Test (LAT), Enzyme-Linked Immunosorbent Assay (ELISA), and Western Blot. Meanwhile, molecular methods such as polymerase chain reaction (PCR), nested PCR, real-time PCR, loop-mediated isothermal amplification (LAMP), multiplex PCR, and PCR–restriction fragment length polymorphism (PCR–RFLP) are also utilized. Each of these methods possess its own set of advantages and disadvantages.
Conclusions
By summarizing the advantages and disadvantages of different diagnostic techniques, it is hoped that the epidemiology, prevention, and control of toxoplasmosis will be improved in the future through the use of appropriate technologies.
... Although horizontal transmission of Toxoplasma and the resultant postnatally acquired toxoplasmosis were long considered asymptomatic in immunocompetent hosts, studies in the last approximately 30 years using animal and human models have uncovered impacts on the infected intermediate host in several aspects. Among these impacts are behavioral changes, which are most probably the result of manipulations by the parasite, see (Abdulai-Saiku, Tong, & Vyas, 2017;Saadatnia & Golkar, 2012;Webster, Brunton, & Macdonald, 1994;Wohlfert, Blader, & Wilson, 2017). ...
Introduction: Latent toxoplasmosis, affecting approximately one-third of people worldwide, was once thought to be asymptomatic. However, studies in the last three decades have revealed that it can cause significant psychological and behavioral changes in humans. The observation that the behavioral impacts of toxoplasmosis manifest in opposite directions in men and women has led to the development of the Stress-Coping Hypothesis. This hypothesis posits that health degradation from toxoplasmosis results in chronic stress, with gender-specific coping strategies explaining the divergent behavioral responses observed between men and women.
Methods: This study, conducted on 1,768 individuals who had previously been tested for toxoplasmosis or borreliosis, sought to examine this hypothesis through a survey that included the Perceived Stress Scale and the State-Trait Anxiety Inventory.
Results confirmed poorer health, higher stress, and anxiety levels among Toxoplasma-infected participants. Path analysis showed that toxoplasmosis directly negatively impacts physical health, which in turn directly increases stress and anxiety among infected individuals, thereby negatively affecting cognitive performance. This pattern was not seen with borreliosis, serving as a negative control, underscoring the unique impact of toxoplasmosis on human physical health, well-being, and cognition.
Conclusions: Our findings strongly suggest that the cognitive impairments associated with toxoplasmosis are primarily side effects of chronic stress resulting from the compromised health of infected individuals.
... gondii) is a strict intracellular parasite that can infect almost all warm-blooded mammals, including human beings, causing severe zoonotic diseases (1). As estimated, approximately 30% of the world's population have been infected with T. gondii (2). Belonged to the TORCH group of diseases (toxoplasmosis, rubella, cytomegaly, herpes), T. gondii can cross the placental barrier, causing teratology, preterm labor, even miscarriage and stillbirth in pregnant women (3). ...
Toxoplasma gondii (T. gondii) is a zoonotic disease that poses great harm to humans and animals. So far, no effective T. gondii vaccine has been developed to provide fully protection against such parasites. Recently, numerous researches have focused on the use of poly-lactic-co-glycolic acid (PLGA) and chitosan (CS) for the vaccines against T. gondii infections. In this study, we employed PLGA and CS as the vehicles for T. gondii ribosome protein (TgRPS2) delivery. TgRPS2-PLGA and TgRPS2-CS nanospheres were synthesized by double emulsion solvent evaporation and ionic gelation technique as the nano vaccines. Before immunization in animals, the release efficacy and toxicity of the synthesized nanospheres were evaluated in vitro. Then, ICR mice were immunized intramuscularly, and immune protections of the synthesized nanospheres were assessed. The results showed that TgRPS2-PLGA and TgRPS2-CS nanospheres could induce higher levels of IgG and cytokines, activate dendritic cells, and promote the expression of histocompatibility complexes. The splenic lymphocyte proliferation and the enhancement in the proportion of CD4⁺ and CD8⁺ T lymphocytes were also observed in immunized animals. In addition, two types of nanospheres could significantly inhabit the replications of T. gondii in cardiac muscles and spleen tissues. All these obtained results in this study demonstrated that the TgRPS2 protein delivered by PLGA or CS nanospheres provided satisfactory immunoprotective effects in resisting T. gondii, and such formulations illustrated potential as prospective preventive agents for toxoplasmosis.
... Toxoplasmosis symptoms in immunocompromised persons are typically self-limiting and include fever, weakness, and lymphadenopathy. The severe form of this disease occurs in immunocompromised persons and pregnant women and is linked with encephalitis, retinochoroiditis, abortion, splenomegaly, and pneumonitis (Saadatnia & Golkar, 2012;Tenter et al., 2000). ...
Cats, being the definitive host of Toxoplasma gondii, have a significant impact on the spread and outbreaks of the parasite. An essential factor in comprehending the transmission pattern of this parasite is an analysis of the genetic diversity distribution in cats infected with T. gondii. This study was aimed at determining the prevalence rate and genotyping of T. gondii in stray cat feces from Khorramabad, West Iran. In the years 2016–2017, 200 cats were sampled to get fresh feces specimens. Parasitological methods were utilized for the identification of oocysts. The DNA was isolated from the feces using a commercially available Genomic Mini Kit. In order to identify the genetic composition of T. gondii, we employed PCR-RFLP, sequencing, and phylogenetic analysis of the GRA6 target gene. No one of the samples tested positive for parasitology techniques. A total of 6.5 % (13/200) samples were positive when using the GRA6-PCR method. Based on PCR-RFLP results, all 13 samples were of T. gondii type III genotype. The nucleotide sequences of two samples from this study were found to be 5 % different from those of 12 references of T. gondii and one strain of Hammondia hamondi that was used as an external control. Based on the findings, molecular tests are more sensitive than parasitological methods. The RFLP approach revealed that type III of T. gondii is the prevailing and important genotype in Khorramabad, West Iran.
... Toxoplasmosis can be diagnosed using various techniques, including PCR, serological methods, immunohistochemistry, and identification of specific sequences in fluids and tissues. Occasionally, toxoplasmin skin tests and identification of the parasite antigen in blood and fluids are also used [58,59]. These methods are particularly helpful when the diagnosis is unclear during ophthalmoscopy. ...
Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii (T. gondii), presents a significant global health concern, particularly for immunocompromised individuals and congenitally infected newborns. Despite its widespread prevalence, there are limited data on T. gondii seroprevalence and ocular toxoplasmosis in Romania. This review aims to summarize the research accomplished on the prevalence and epidemiology of human ocular toxoplasmosis in Romania. Ocular toxoplasmosis, a leading cause of infectious posterior uveitis worldwide, involves complex interactions between host immune responses and parasite factors. Clinically, it presents as focal necrotizing retinitis, characterized by active focal retinal lesions with adjacent chorioretinal scarring, often accompanied by vitreous inflammation and anterior chamber reactions. Diagnosis relies on clinical examination supported by fundus photography, optical coherence tomography (OCT), and serological assays. The authors followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards, conducting a literature review on PubMed, Google Scholar, and Scopus. Our focus was on ocular toxoplasmosis in Romania, and we used keywords and specific MeSH terms. Finally, 17 articles met all the criteria, as summarized in the PRISMA diagram. This study underscores the need for improved diagnostic methods, increased research efforts, and comprehensive public health education to mitigate the burden of toxoplasmosis and ocular toxoplasmosis in Romania.
... This ubiquitous pathogen is estimated to chronically infect up to one third of the global human population [2]. Chronic-stage parasites serve as reservoirs for reactivated disease under the setting of host immune dysfunction, which can lead to severe consequences such as encephalitis and blindness in affected host organs [2][3][4]. There have also been reports of reactivation in otherwise healthy individuals [5,6]. ...
Toxoplasma gondii is a ubiquitous protozoan parasite that can reside long-term within hosts as intracellular tissue cysts comprised of chronic stage bradyzoites. To perturb chronic infection requires a better understanding of the cellular processes that mediate parasite persistence. Macroautophagy/autophagy is a catabolic and homeostatic pathway that is required for T. gondii chronic infection, although the molecular details of this process remain poorly understood. A key step in autophagy is the initial formation of the phagophore that sequesters cytoplasmic components and matures into a double-membraned autophagosome for delivery of the cargo to a cell’s digestive organelle for degradative recycling. While T. gondii appears to have a reduced repertoire of autophagy proteins, it possesses a putative phospholipid scramblase, TgATG9. Through structural modeling and complementation assays, we show herein that TgATG9 can partially rescue bulk autophagy in atg9Δ yeast. We demonstrated the importance of TgATG9 for proper autophagosome dynamics at the subcellular level using three-dimensional live cell lattice light sheet microscopy. Conditional knockdown of TgATG9 in T. gondii after bradyzoite differentiation resulted in markedly reduced parasite viability. Together, our findings provide insights into the molecular dynamics of autophagosome biogenesis within an early-branching eukaryote and pinpoint the indispensable role of autophagy in maintaining T. gondii chronic infection.
... Toxoplasmosis is a signifi cant disease caused by an intracellular obligate parasite known as Toxoplasma gondii, which has a complex life cycle (Galvan-Ramirez et al., 2012;Saki et al., 2015). T. gondii, the causative agent of toxoplasmosis, is widespread globally, infecting both humans and animals, and oft en leads to chronic infections in high percentage (Daryani et al., 2014;Dubey et al., 2014;Saadatnia & Golkar, 2012). Th is protozoan parasite infects both warm-blooded animals and humans, but the prevalence of infection is higher in humans than in animals (Nicolle & Manceaux, 2009). ...
Toxoplasmosis is a parasitic infection, with widespread gestational and congenital transmission rates globally, consequently, it is regarded as a public health concern and an overlooked medical condition. Human infection occurs through various routes, including the ingestion of oocysts found in cat feces, consumption of raw or undercooked meat containing the parasite, and vertical transmission from an infected pregnant mother to her fetus. Objective. The aim of this study is to determine the prevalence of Toxoplasma gondii infection among individuals in various age groups and genders in Duhok City. Methods. In this research, 2251 individuals of various ages and genders visited the central laboratory in Duhok Сity, Kurdistan Region, Iraq, and peripheral blood samples were taken from individuals to identify specific anti-Toxoplasma gondii IgM and IgG antibodies using serological test (ELISA test). Results. Based on the findings of this study, it was observed that the prevalence of toxoplasmosis among females with infections detected in both IgM and IgG was 0.3 % and 20.6 %, respectively, and in males, the rate of infection with IgG was found to be 0.3 %, while no infections were detected with IgM. Also, among female individuals, the study recorded a 0.3 % infection rate for toxoplasmosis, which encompassed both IgM and IgG cases. Conclusions. Based on this study, it can be concluded that Toxoplasma infection is more common in females than in males, chronic toxoplasmosis appears to be more prevalent than acute infection with the highest rate of acute infections was found in the age group of 21–40 years.
... Indeed, T. gondii is ranked 4th in the global ranking of food-borne parasites (FAO/WHO 2014) and second in the European Union (Bouwknegt et al. 2018). It has been estimated that up to one third of the global population may be infected by T. gondii (FAO/ WHO 2014; Montoya and Liesenfeld 2004;Petersen and Dubey 2001;Saadatnia and Golkar 2012), and more than a million cases of toxoplasmosis are reported in Europe per annum (WHO 2015). ...
Toxoplasma gondii is an obligate intracellular parasite associated with severe disease, especially in the immunosuppressed. It is also a cause of congenital malformation and abortion in both animals and humans and is considered one of the most important foodborne pathogens worldwide with different strains showing variable distribution and differing pathogenicity. Thus, strain-level differentiation of T. gondii isolates is an essential asset in the understanding of parasite’s diversity, geographical distribution, epidemiology and health risk. Here, we designed and implemented an Oxford Nanopore MinION protocol to analyse genomic sequence variation including single nucleotide polymorphisms (SNPs) and insertion/deletion polymorphisms (InDel’s) of four different genomic loci, part of protein coding genes SAG2, SAG3, ROP17 and ROP21. This method provided results with the sequencing depth necessary for accurate differentiation of T. gondii strains and represents a rapid approach compared to conventional techniques which we further validated against environmental samples isolated from wild wood mice. In summary, multi-locus sequence typing (MLST) of both highly conserved and more polymorphic areas of the genome, provided robust data for strain classification in a platform ready for further adaption for other strains and pathogens.
... Laboratory diagnostic methods for systemic toxoplasmosis include polymerase chain reaction (PCR), serologic testing, immunohistochemical identification, in vitro culture, and animal inoculation. Rarely, detection of antigens in serum and body fluids, skin tests, and antigen-specific lymphocyte transformation have also been used (67). Detection of specific antibodies in the aqueous and vitreous humor as well as PCR-based assays can be effectively used to diagnose OT (68). ...
Ocular toxoplasmosis (OT) is an intraocular infection caused by the parasite Toxoplasma gondii. OT is manifested as retinal choroiditis and is the most common infectious cause of posterior uveitis. Invasion of the retina by T. gondii leads to disruption of the blood-ocular barrier and promotes the migration of immune cells to the ocular tissues. Cytokines such as IFN-γ and IL-1β are effective for controlling parasite growth, but excessive inflammatory responses can cause damage to the host. In this review, we will discuss in detail the latest advances in the immunopathology and treatment of OT.
... Toxoplasmosis (TS) is a frequent parasitic infection in both humans and animals, caused by Toxoplasma gondii [1]. According to seroepidemiological studies, a significant proportion of the world's people is seropositive for this parasitic infection [2]. ...
The present in vitro and in vivo study aimed to fabricate and characterize linalool-zinc oxide nanoparticles (Lin-ZNP) and evaluate their effectiveness against Toxoplasma gondii infection in terms of inflammation, oxidative stress, and pathogenicity. Lin-ZNP was synthesized using an ethanolic solution of polyvinyl alcohol. The anti-Toxoplasma and cytotoxicity activities of Lin-ZNP were investigated, along with its effects on nitric oxide (NO) production, caspase-3 activity, and pro-inflammatory genes. After treating T. gondii-infected mice with Lin-ZNP for 14 days, the number and size of tissue cysts, antioxidant potential, pro-inflammatory cytokines, and T. gondii pathogenicity-related genes were evaluated by real-time polymerase chain reaction and Western blot analysis. The Lin-ZNP composite showed a reduced tendency with an average size of 105 nm. Lin-ZNP significantly reduced the viability of tachyzoites. The obtained selectivity index higher than 10, indicating high specificity for parasites with low cytotoxicity to normal cells. The Lin-ZNP significantly (p < 0.05) increased the production of NO, caspase-3 activity, and the expression levels of pro-inflammatory genes. Lin-ZNP significantly (p < 0.001) decreased the size and number of tissue cysts and caused a significant reduction in the level of malondialdehyde and a considerable increase (p < 0.001) in antioxidant enzymes and their expression genes. Lin-ZNP significantly downregulated both mRNA and protein expression of the inflammation-related markers associated with the TLRs/ NF-κB pathway. The expression levels of the T. gondii pathogenicity-related genes were significantly downregulated (p < 0.05). The recent survey indicated that Lin-ZNP manages T. gondii infection by its antioxidant activity and inhibiting the TLRs/NF-κB pathway without toxicity in mice.
... Our model does not consider selfawareness [35], but it is suitable for some infectious diseases with no obvious or mild symptoms. For example, most people infected with Toxoplasma gondii are asymptomatic carriers [44]. Ignoring selfawareness can make the contrast clearer. ...
The duration of the accumulation rate (physical image) is a key factor in analysis of counterintuitive phenomena involving relative timescales on multiplex networks. Typically, the relative timescales are represented by multiplying any layer by the same factor. However, researchers often overlook the changes in the relative timescales caused by local parameters, resulting in incomplete analysis of phenomena. This paper examines the survival time of stifler individuals in the information-epidemic model on multiplex networks. The relative timescales can be affected by the survival time (only one parameter), reversing the monotonically increasing phenomenon into a monotonically decreasing one, that is, a counterintuitive phenomenon under incomplete analysis. Additionally, the relative timescales can influence the epidemic threshold, which is different from the previous studies. Our work suggests that considering the physical image of relative timescales is crucial when analyzing multiplex networks, even when only one parameter is altered.
... Toxoplasmosis (disease caused by Toxoplasma gondii) is one of the most common parasitic infections of humans and other warm-blooded animals. This infection has been observed especially in developing countries with a prevalence of 30-60% [1]. T. gondii infection cases are prevalent in tropical and subtropical regions and it has been shown that the problem of global warming plays an important role in the distribution and spread of the disease [2]. ...
The present experimental survey designed to green synthesis, characterization, as well as in vitro and in vivo anti-Toxplasma gondii activity of silver nanoparticles (SLN) green synthesized by Lupinus arcticus extract. SLN were green synthesized based on the reducing by L. arcticus extract through the precipitation technique. In vitro lethal effects of SLN on T. gondii tachyzoites, infectivity rate, parasites inside of the human macrophage cells (THP-1 cells), nitric oxide (NO) triggering, and iNOS and interferon gamma (IFN-γ) expression genes were evaluated. In vivo, after establishment of toxoplasmosis in BALB/c mice via T. gondii ME49 strain, mice received SLN at 10 and 20 mg/kg/day alone and combined to pyrimethamine at 5 mg/kg for 14 days. SLN exhibited a spherical form with a size ranging from 25 to 90 nm. The 50% inhibitory concentration (IC50) value of SLN and pyrimethamine against tachyzoites was 29.1 and 25.7 µg/mL, respectively. While, the 50% cytotoxic concentration (CC50) value of SLN and pyrimethamine against THP-1 cells was 412.3 µg/mL and 269.5 µg/mL, respectively. SLN in combined with pyrimethamine obviously (p < 0.05) decreased the number and size of the T. gondii cysts in the infected mice. The level of NO, iNOS and IFN-γ genes was obviously (p < 0.001) upregulated. SLN obviously (p < 0.05) decreased the liver level of oxidative stress and increased the level of antioxidant factors. The findings displayed the promising beneficial effects of SLN mainly in combination with current synthetic drugs against latent T. gondii infection in mice. But we need more experiments to approve these findings, clarifying all possible mechanisms, and its efficiency in clinical phases.
... toxoplasmosis are based on the combination of pyrimethamine and sulfadiazine, often accompanied by substantial bone marrow toxicity and ineffectiveness against chronic infection cysts of T. gondii [5,6]. Therefore, future anti-T. ...
Background
Toxoplasmosis is a zoonotic disease caused by the infection of the protozoa Toxoplasma gondii (T. gondii), and safe and effective therapeutic drugs are lacking. Mitochondria, is an important organelle that maintains T. gondii survival, however, drugs targeting mitochondria are lacking.
Methods
The cytotoxicity of BAM15 was detected by CCK-8 and the in vitro effects of BAM15 was detected by qPCR, plaque assay and flow cytometry. Furthermore, the ultrastructural changes of T. gondii after BAM15 treatment were observed by transmission electron microscopy, and further the mitochondrial membrane potential (ΔΨm), ATP level and reactive oxygen species (ROS) of T. gondii after BAM15 treatment were detected. The pharmacokinetic experiments and in vivo infection assays were performed in mice to determine the in vivo effect of BAM15.
Results
BAM15 had excellent anti-T. gondii activity in vitro and in vivo with an EC50 value of 1.25 μM, while the IC50 of BAM15 in Vero cells was 27.07 μM. Notably, BAM15 significantly inhibited proliferation activity of T. gondii RH strain and Prugniaud strain (PRU), caused T. gondii death. Furthermore, BAM15 treatment induced T. gondii mitochondrial vacuolation and autolysis by TEM. Moreover, the decrease in ΔΨm and ATP level, as well as the increase in ROS production further confirmed the changes
Conclusions
Our study identifies a useful T. gondii mitochondrial inhibitor, which may also serve as a leading molecule to develop therapeutic mitochondrial inhibitors in toxoplasmosis.’
Graphical Abstract
... Toxoplasma gondii is The most widespread parasite in developed and developing countries, where it poses serious social and economic damage all over the world due to its wide spread for being one of the most successful parasites [3], The symptoms of infection depend on the immune status of the patient and the severity of the infection, as the infection is usually asymptomatic in immunocompetent persons, or the symptoms may be limited to fever, headache and muscle pain similar to the symptoms of influenza [4]. The parasite is also transmitted through blood transfusion, organ transplant, semen, eating raw eggs, or through consumption of unpasteurized milk of infected animals containing the Tachyzoite [5], [6]. ...
... Toxoplasmosis (TOP), which is derived from the Toxoplasma gondii parasite, is recognized as one of the most common parasitic diseases in the world (Saadatnia & Golkar, 2012;Molan et al., 2019). Humans acquire this infection by ingesting T. gondii cysts in food and water, by ingesting tissue cysts in raw and undercooked meat (Martinez et al., 2018), and via spreading to the placenta during pregnancy (Al-Agroudi, et al., 2017). ...
The present study was conducted to investigate the immunomodulatory and anti-inflammatory effects of Elettaria cardamomum essential oil (ECEO) for the control of acute Toxoplasma gondii infection. The effect of ECEO on T. gondii tachyzoites was measured by the tetrazolium bromide method. Mice received ECEO orally at doses of 1-4 mg/kg/day for 14 days. Once acute toxoplasmosis was induced in mice, their mortality rate and parasite load were recorded. The level of liver antioxidant/oxidant enzymes and the level of mRNA expression of interleukin-1 beta and interferon-gamma were also investigated. ECEO particularly at a concentration of 150 µg/ml has promising in vitro anti-Toxoplasma effects (p<0.001). After treatment with ECEO, the mortality rate (9th day) and parasite load decreased (p<0.001) in the infected mice. ECEO markedly (p < 0.05) restored hepatic oxidant and antioxidant enzyme levels, as well as increased cytokines. These results report a significant inhibitory effect of ECEO mainly at a dose of 4 mg/mL, against the T. gondii Rh strain through strengthening the immune system and reducing inflammation and oxidative stress; however, further research is needed to verify these results.
... Furthermore, regarding of Toxoplasma's ability to cause severe illness, being high incidence, and being potential for prevention, the centers of control diseases have prioritized Toxoplasma as one of the top five neglected parasitic infections [1], [36]. The infection occurs in all ages, and it is increased with age and it does not vary greatly between males and females [37]. The disease caused is called toxoplasmosis, and it manifests a wide variety of clinical manifestation in human beings from abortion to fatal encephalitis [38]. ...
In this work, the protozoan of Toxoplasma gondii (Nicolle & Manceaux, 1908) (Apicomplexa:Sarcocystidae) is reviewed. Toxoplasma gondii is intracellular parasite belonging to the phylum of apicomplexa. It is a common protozoan of warm-blooded animals, and it distributes worldwide, causing infection in eyes' retina, brain and other regions of the body. It has been reported that toxoplasmosis is one of neglected disease by CDC. The first discovery of this intracellular parasite was in 1908, and later in 1957 was detected causing abortion in animal. In 1970, it was the first time for recognizing the life cycle of it, they were found that cats (felids in general) are the final host, and the stage of oocyst is occurring in the stool of infected cats. For prevention, T.gondii can be prevented by hygiene, and it considers the only way preventive measure because vaccination technology is not discovered yet for toxoplasmosis prevention in human.
... Despite the fact that the infection is asymptomatic or mild in healthy people, transmission during pregnancy in the first exposure can be very disastrous leading to severe complications, e.g., hydrocephaly, miscarriage, and even death (3). Besides, it has been recognized as opportunistic and fatal in immunocompromised persons, e.g., organ transplant patients (4,5). ...
Introduction: Formononetin (FMN) is a natural isoflavone found in many plants. This work examined the anti-Toxoplasma effects and cytotoxicity properties of FMN on Toxoplasma gondii. Methods: Effects of FMN (2-64 µg/mL) on tachyzoites forms were measured by cell viability assay for 48 hours. The effects of different concentrations of FMN on infectivity rate, intracellular parasites, and nitric oxide (NO) in macrophage cells (J774-A1) were also evaluated. Results: FMN markedly (P<0.001) reduced the viability rate of tachyzoites forms with an IC50 value of 9.85 μg/mL. FMN also declined the rate of intracellular tachyzoites whereas, FMN increased the FMN production in macrophage cells. Conclusion: The results of the present in vitro study revealed the favorable anti-Toxoplasma effects of FMN against tachyzoites and intracellular forms of T. gondii. Although the accurate anti-Toxoplasma mechanisms of FMN are not clear, our results showed that triggering the NO production might be considered one of the main mechanism actions of FMN for controlling and eliminating T. gondii. However, further surveys are mandatory to assess the effects of FMN in animal models and to evaluate its accurate mechanism actions before its use in clinical phase.
... Toxoplasma gondii infection (TGI) is recognized as a highly prevalent parasitic disease in humans and other warm-blooded animals, especially in tropical and subtropical regions [1,2]. Humans are infected by eating cysts from raw meat (e.g., beef and pork), ingesting oocysts in food contaminated with cat feces, and placental diffusion [3]. ...
Background: Nowadays, interest in the use of nanotechnology for medical purposes is increasing. The current experimental investigation is planned for the green synthesis, characterization, and efficacy of copper nanoparticles (CLN) against chronic Toxoplasma gondii infection. Methods: Green synthesis of CNP was performed using the Lupinus arcticus extract via the precipitation method. The effects of CNP on tachyzoites, infectivity rate, parasites inside THP-1 cells, nitric oxide (NO) triggering, iNOS, and IFN-γ expression genes were evaluated. Following toxoplasmosis in BALB/c mice via the T. gondii ME49 strain, mice received CNP at 5 and 10 mg/kg/day alone and combined with pyrimethamine (PYM) at 5 mg/kg for two weeks. CNP's in vivo effects were evaluated by analyzing the load and size of cysts, oxidant/antioxidant enzymes, and bradyzoite surface antigen 1 (BAG1) expression gene levels. Results: CNP displayed a circular shape ranging from 10 to 85 nm. The IC50 value of CNP and PYM against tachyzoites was 37.2 and 25.7 µg/mL, respectively, whereas the CC50 value of CNP and pyrimethamine against THP-1 cells was 491.4 µg/mL and 269.5 µg/mL, respectively. The rate of infectivity and parasite load among THP-1 cells exposed to CNP was obviously reduced (p < 0.05). CNP at the doses of 5 and 10 mg/kg predominantly along with PYM evidently (p < 0.05) reduced the number and size of the T. gondii cysts in the infected mice. The levels of NO, iNOS, and IFN-γ genes were remarkably (p < 0.001) boosted compared with the cells without treatment. CNP at the doses of 10 and 20 mg/kg drastically (p < 0.05) reduced the oxidative stress markers in the infected mice, whereas CNP significantly elevated the level of antioxidant factors. CNP also revealed no toxicity in the liver and kidney at the tested doses in healthy mice. Conclusions: Our experimental study reported the beneficial effects of CNP principally along with existing chemical drugs against latent toxoplasmosis in mice, whereas the possible action mechanisms of CNP are controlling oxidative stress, refining antioxidant enzymes, and increasing the production of immunomodulatory cytokines with no toxicity to the function of vital organs. But, additional trials are required to confirm these results, as well as to clarify the accurate mechanisms and their toxicity.
... In addition, the possibility of false positive IgM antibodies can lead to difficulties in diagnosis, and issues such as confirmation of positive values by other methods and understanding the stage of infection require the application of IgG avidity test. Understanding early or late toxoplasmosis is of great clinical importance in pregnant women and immunocompromised cases [10][11][12][13]. The aim of this study is to evaluate the frequency of the presence of T. gondii antibodies between different sexes and age groups by Sabin Feldman Dye test and ELISA IgG/IgM seroconventional methods in cases sent to the laboratory in 2019-2020. ...
Toxoplasma gondii is a unicellular protozoan parasite. With this study, the aim was to evaluate the T. gondii test results that came to the General Directorate of Public Health, National Parasitology Reference Laboratory between January 2019 and December 2020. The seroprevalence were studied with the Sabin-Feldman Dye Test which is gold standard, Anti-T. gondii IgG and IgM and T. gondii IgG avidity with ELISA were evaluated. The distribution of cases according to gender and age groups was also evaluated statistically. In this study, SFDT was performed on 589 patients from 1160 patients with suspected Toxoplasmosis samples and Anti-T. gondii IgG and IgM tests were studied by ELISA in 478 patients. IgG avidity test by ELISA was performed on 93 cases with positive Anti- T. gondii IgG. In addition to these, cases in which Anti-T. gondii IgM and IgG were studied together and were positive were also evaluated. The number of samples both positive together was 17 (3.6%). According to Anti-T. gondii IgG/IgM results, no significant relationship was found between toxoplasmosis and gender. Moreover, of 93 cases with positive Anti-T. gondii IgG values, 71% had high avidity, 16% had cutoff value and 13% had low avidity. Further studies and surveillance studies should be performed to determine the epidemiology and current prevalence of toxoplasmosis.
... Human infection with T. gondii usually occurs through consumption of oocyst-contanimated vegetables or undercooked meat, and congenital transmission when primary infection occurs during pregnancy [11]. Toxoplasmosis is usually asymptomatic [12][13][14] and up to one-third of humans may be infected globally [15][16][17]. However, clinical forms are sometimes observed, especially in immuno-compromized patients and fetuses [18][19][20][21] as well as in immuno-competent individuals from tropical regions infected with T. gondii atypical strains that circulate specifically in the environment of these geographical areas [22][23][24]. ...
A growing number of studies has highlighted the importance of co-infections in eco-evolutionary processes underlying host-parasite interactions and the resulting epidemiology of zoonotic agents. Small mammals, and particularly rodents, are known to be important reservoirs of many zoonotic pathogens, such as Toxoplasma gondii and Trypanosoma lewisi that are responsible for toxoplasmosis and atypical trypanosomiasis in human, respectively. Laboratory experiments on rodent models have shown that primary infection with T. lewisi increases the host susceptibility to other co-infectious parasites, including T. gondii, following an alteration of the immune system. However, data on potential interactions between these parasites in wild small mammals remain scarce. In this study, we estimate the T. lewisi prevalence in 553 small mammals from four localities of Cotonou city, Benin. They were then combined with T. gondii data previously collected on the same individuals in order to investigate the influence of T. lewisi on T. gondii infection, and vice-versa, using cooccurrence tests and Generalized Linear Mixed Models. Despite quite high overall prevalence (32.5% and 15.2% for T. gondii and T. lewisi, respectively), we observed a clear and significant segregation between the two parasites. This may be explained by (i) differences in the species-specific susceptibility of small mammal host species to infection by these two parasites, with R. rattus and M. natalensis being the main reservoirs of T. lewisi while C. olivieri and M. m. domesticus are the main hosts for T. gondii; and/or by (ii) a possibly high mortality in co-infected animal in the wild. Although dedicated experimental studies are required to confirm this pattern, as they stand, our data fail to support that infection of small mammals by one of these two parasites favours widespread infection by the second one in nature.
... Parasites may cause serious problems, including encephalitis and pneumonia, in persons who don't have functioning immune systems 2 . Pregnant women infected with this protozoan parasite may have a premature delivery, abortion, teratosis, or stillbirth, and neonates may develop ocular and neurological abnormalities 3 . T. gondii causes abortion, stillbirth, and deformities in sheep, pigs, and sows, resulting in major economic losses to the livestock sector [4][5][6] . ...
Toxoplasma gondii is an obligate parasitic protozoon that transmits to animals and humans via ingested food. Cats that act as T. gondii’ s final hosts play a critical role in T. gondii transmission by shedding millions of oocysts. Timely diagnosis of infected cats is essential for preventing toxoplasmosis because oocysts are a putative T. gondii source in epidemiology. We developed a new visual LAMP assay targeting the B1 gene to analyze single oocysts in cat feces in this study. The amplification result could be visually estimated based on the color change. LAMP assay analytical sensitivity was 10 ¹ copies/µL for the B1 gene plasmid, which was tenfold better than the PCR reaction. There were no cross-reactions with other parasites. The LAMP assay can detect a single T. gondii oocyst in 200 mg of cat feces. The LAMP assay detected a single oocyst in 200 mg cat feces at a higher rate than the PCR assay (83.3% vs. 50.0%).
... Reproductive disorders have also been reported in goat and sheep infected with T. gondii [21]. In humans, encephalitis, abortion or stillbirth, and retinochoroiditis are common symptoms of toxoplasmosis [18]. These findings indicate that T. gondii parasites that invade the intestinal tract migrate to the respiratory tract, nervous system (including the eyes), and reproductive organs, causing disease. ...
Many parasite species migrate to another site of infection after entering the host body. Such parasite dynamics are closely related to pathogenicity, but it is not easy to observe such parasite behavior deep within the organs. In recent years, technology that can make organs transparent has been developed that enables us to observe deep within organs ex vivo while maintaining their three-dimensional structure. This review describes a series of attempts to apply this technology to understand the behavior of Toxoplasma gondii in the host body. A series of studies has shown that T. gondii tachyzoites that infect leukocytes can reach target organs far from the site of invasion via the circulatory system. In addition, infected leukocytes in the bloodstream adhere more readily to vascular endothelial cells than uninfected leukocytes and are more likely to remain inside the target organs. When infected leukocytes adhere to the vascular endothelial cells of the target organ, the tachyzoites inside the cells immediately escape and infect the parenchyma of the organs. As described above, organ transparency technology is a powerful tool for understanding the internal dynamics of parasites.
Toxoplasmosis, which is created by the Toxoplasma gondii parasite is a parasitic, infectious disease. 10-hydroxy-2-decenoic acid (10-H2DA, queen bee acid (QBA), is one of the most prevalent fatty acid (>40%) presents in royal jelly. Studies reported various beneficial effects of 10-H2DA antitumor, anti-inflammatory, antiangiogenic, improving the immune system, and antimicrobial effects. This experimental survey aimed to evaluate the in vitro efficacy of QBA against tachyzoites and intracellular parasites of the T. gondii RH strain. Anti-Toxoplasma effects of QBA against tachyzoites were examined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay for 30, 60, 120, and 180 min. In addition, the effect of QBA on infection rate and intracellular parasites was studied. Real-time PCR was also applied to assess the expression level of the Caspase-3 gene. The best efficiency of QBA was reported at 100 and 50 µg/mL whereas all tachyzoites were diminished followed by 120- and 180-min treatment, respectively. We also found that the best repressing efficacy of QBA on the infection rate and the load of parasites into the Vero cells was indicated at 100 µg/mL (p<0.001): but, the combination of QBA (12.5 µg/mL) along with atovaqoune 30 µg/mL displayed the highest effect on the infection rate and the load of parasites into the Vero cells in the infected Vero cells. The expression level of the Caspase-3 gene was dose-dependently increased after exposure of tachyzoites to QBA; mainly at ½ IC50, and IC50 compared to the normal saline. The achieved findings exhibited the high in vitro potency of QBA especially in combination with atovaqoune against T. gondii RH strain tachyzoites. Although apoptosis induction can be suggested as one of the principle mechanisms; more studies are required to elucidate its accurate mechanisms as well as its efficacy and safety in animal models and clinical settings.
Macroautophagy is an important cellular process involving lysosomal degradation of cytoplasmic components, facilitated by autophagy-related proteins (ATGs). In the protozoan parasite Toxoplasma gondii , autophagy has been demonstrated to play a key role in adapting to stress and persistence of chronic infection. Despite limited knowledge about the core autophagy machinery in T. gondii , two PROPPIN family proteins (TgPROP1 and TgPROP2) have been identified with homology to Atg18/WIPI. Prior research in acute stage tachyzoites suggests that TgPROP2 is predominantly involved in a non-autophagic function, specifically apicoplast biogenesis, while TgPROP1 may be involved in canonical autophagy. Here, we investigated the distinct roles of TgPROP1 and TgPROP2 in chronic stage T. gondii bradyzoites, revealing a critical role for TgPROP1, but not TgPROP2, in bradyzoite autophagy. Conditional knockdown of TgPROP2 did not impair bradyzoite autophagy. In contrast, TgPROP1 KO parasites had impaired autolysosome formation, reduced cyst burdens in chronically infected mice, and decreased viability. Together, our findings clarify the indispensable role of TgPROP1 to T. gondii autophagy and chronic infection.
Importance
It is estimated that up to a third of the human population is chronically infected with Toxoplasma gondii ; however, little is known about how this parasite persists long term within its hosts. Autophagy is a self-eating pathway that has recently been shown to play a key role in parasite persistence, yet few proteins that carry out this process during T. gondii chronic infection are known. Here, we provide evidence for a non-redundant role of TgPROP1, a protein important in the early steps of the autophagy pathway. Genetic disruption of TgPROP1 resulted in impaired autophagy and chronic infection of mice. Our results reveal a critical role for TgPROP1 in autophagy and underscore the importance of this pathway in parasite persistence.
Toxoplasma gondii (T. gondii) infects one third of the world’s population with significant illness, mainly among immunocompromised individuals and pregnant women. Treatment options for toxoplasmosis are limited which signifies the need for novel, potent, and safe therapeutic options. The goal of this study was to assess the effectiveness of the ethanolic extract of Zingiber officinale (Z. officinale) in treating mice infected with the RH T. gondii strain.
Gas Chromatography/Mass Spectrometry (GC/MS) was used to identify components of ethanolic extract of Z. officinale. A total of 80 mice were randomly allocated into four experimental groups that contained 20 mice each. The first group was left uninfected (uninfected control), while three groups were infected with T. gondii RH virulent strain tachyzoites at 2500 tachyzoites/mouse. One infected group was left untreated (infected, untreated), whereas the other two groups were treated orally with either spiramycin (positive control) or Z. officinale ethanolic extract at doses of 200 mg/kg and 500 mg/kg, respectively for 5 days, starting the day of infection. Ten mice from each group were used to assess mice survival in different groups, whereas the other ten mice in each group were sacrificed on the 5th day post-infectin (dpi) to estimate the treatment efficacy by quantifying liver parasite load, liver function, nitric oxide (NO) production, and levels of antioxidant enzymes. Additionally, histopathological studies were performed to evaluate the therapeutic effect of Z. officinale treatment on toxoplasmosis-induced pathological alterations in liver, brain, and spleen.
Treatment with Z. officinale ethanolic extract extended the survival of mice till 9th dpi compared to 7th dpi in infected untreated mice. Higher percentage of mice survived in Z. officinale-treated group compared to spiramycin-treatment group at different time points. Liver parasite loads were significantly lower in Z. officinale extract-treated mice and spiramycin-treated mice compared to infected untreated mice which correlated with significantly lower levels of serum liver enzymes (ALT, AST) and nitric oxide (NO), as well as significantly higher catalase (CAT) antioxidant enzyme activity. Scanning electron microscopy (SEM) examination of tachyzoites from the peritoneal fluid revealed marked damage in tachyzoites from Z. officinale-treated group compared to that from infected untreated mice. Moreover, treatment with Z. officinale ethanolic extract alleviated infection-induced pathological alterations and restored normal tissue morphology of liver, brain, and spleen.
Our results demonstrated that Z. officinale treatment reduced parasite burden and reversed histopathological and biochemical alterations in acute murine toxoplasmosis. These findings support the potential utility of Z. officinale as a future effective natural therapeutic for toxoplasmosis. Further studies are needed to determine the effective active ingredient in Z. officinale extract that can be further optimized for treatment of toxoplasmosis.
The aim of this study was to estimate the molecular infection prevalence of Toxoplasma gondii in sheep liver tissues destined for human consumption. A total number of 224 liver tissues were collected from slaughtered sheep in Sejnane slaughterhouse (Northwest Tunisia). PCR was used to detect T. gondii DNA in liver tissues followed by phylogenetic analysis of amplicons. The phylogenetic tree was then constructed to compare the partial sequences of the ITS1 gene with GenBank sequences.The overall molecular prevalence of T. gondii in sheep livers was 25% (56/224). The highest molecular prevalence of T. gondii was recorded in sheep aged of less than one year old (27.3%; 52/190). Infection prevalence was significantly higher in Noire de Thibar breed (33%; 17/51) compared to other breeds (p = 0.023). There were no differences depicted according to sheep's gender. The T. gondii sequences obtained in the present study (GenBank accession numbers: OR509829 and OR509830) were 98.40-100% homologous to T. gondii sequences published in the GenBank. These results highlight a high level of T. gondii contamination of tissues destined for human consumption. Further studies are needed to improve our knowledge on different genotypes of T. gondii that infect Tunisian sheep population.
Over two billion people worldwide are infected with the protozoan Toxoplasma gondii, which influences human behavior and cognition. Standard diagnosis methods involve costly medical tests, which prevents widespread testing and hinders the study of the infection's effects. We propose and validate an inexpensive and easy-to deploy diagnostic method for latent Toxoplasmosis infections using response times and finite-mixture models. A clinical study showed that the method is sensitive and accurate. A large, representative UK study showed that the infection's consequences are relevant and pervasive, both economically (decrease in yearly income and employment) and behaviorally (increase in risky behaviors, stress, and depression).
Immunoglobulin G (IgG) and immunoglobulin M (IgM) testing are commonly used to determine infection status. Typically, the detection of IgM indicates an acute or recent infection, while the presence of IgG alone suggests a chronic or past infection. However, relying solely on IgG and IgM antibody positivity may not be sufficient to differentiate acute from chronic infections. This limitation arises from several factors. The prolonged presence of IgM can complicate diagnostic interpretations, and false positive IgM results often arise from antibody cross-reactivity with various antigens. Additionally, IgM may remain undetectable in prematurely collected samples or in individuals who are immunocompromised, further complicating accurate diagnosis. As a result, additional diagnostic tools are required to confirm infection status. Avidity is a measure of the strength of the binding between an antigen and antibody. Avidity-based assays have been developed for various infectious agents, including toxoplasma, cytomegalovirus (CMV), SARS-CoV-2, and avian influenza, and are promising tools in clinical diagnostics. By measuring the strength of antibody binding, they offer critical insights into the maturity of the immune response. These assays are instrumental in distinguishing between acute and chronic or past infections, monitoring disease progression, and guiding treatment decisions. The development of automated platforms has optimized the testing process by enhancing efficiency and minimizing the risk of manual errors. Additionally, the recent advent of real-time biosensor immunoassays, including the label-free immunoassays (LFIA), has further amplified the capabilities of these assays. These advances have expanded the clinical applications of avidity-based assays, making them useful tools for the diagnosis and management of various infectious diseases. This review is structured around several key aspects of IgG avidity in clinical diagnosis, including: (i) a detailed exposition of the IgG affinity maturation process; (ii) a thorough discussion of the IgG avidity assays, including the recently emerged biosensor-based approaches; and (iii) an examination of the applications of IgG avidity in clinical diagnosis. This review is intended to contribute toward the development of enhanced diagnostic tools through critical assessment of the present landscape of avidity-based testing, which allows us to identify the existing knowledge gaps and highlight areas for future investigation.
Se presenta el caso de un paciente masculino de 14 años, sin antecedentes patológicos conocidos, con historia de 2 semanas de edemas en miembros inferiores a quién se le documentó síndrome nefrótico. El cuadro evolucionó a shock séptico, deterioro hemodinámico y posterior muerte. En la autopsia se documentó la presencia de una crisis drepanocítica generalizada con trombosis de la microvasculatura y nefropatía drepanocítica (glomerulopatía colapsante).
Background and Objective: Hesperidin and neohesperidin are naturally occurring citrus flavanone glycosides that have a wide range of therapeutic uses. There is an increasing preference for natural products as chemotherapeutic agents. In this study, comprehensive research presented on the inhibitory effects of hesperidin and neohesperidin dihydrochalcone against 6 different species of Trypanosoma, as well as an analysis of their potential mechanism of action. Materials and Methods: The trypanocidal activity was evaluated using six trypanosome species cultivated in HMI-9 medium. Molecular docking procedures were conducted focusing on the Trypanosoma brucei Dihydrofolate Reductase (TbDHFR), with compound structures sourced from PubChem and optimized for physiological pH. Additionally, molecular dynamics (MD) simulations were carried out over 50 ns, assessing parameters such as RMSD, RMSF and hydrogen bonds to provide insights into the compound’s stability and interactions. Data analysis utilized descriptive statistics to summarize the variations observed in the trypanocidal effects and molecular interactions. Results: The findings indicated that hesperidin lacked antitrypanosomal effects. On the other hand, neohesperidin dihydrochalcone showed significant trypanocidal activity across a wide range of Trypanosoma strains, including Trypanosoma brucei brucei GUT at 3.1, T. b. rhodesiense IL1501, T. b. gambiense IL1922, T. evansi Tansui, T. equiperdum IVM-t1 and T. congolense IL3000. The estimated IC50 values ranged from 8.88 to 22.53 μg/mL, indicating low micromolar inhibition of Trypanosoma. Through docking and MD simulations, it is confirmed that neohesperidin dihydrochalcone binds to TbDHFR. The results of MD simulation support stable complex of neohesperidin dihydrochalcone with TbDHFR. Conclusion: The demonstrated efficacy of neohesperidin dihydrochalcone across various Trypanosoma species endorses its potential as a secure, natural agent against trypanosomiasis. It is strongly advised to further investigate the creation of analogues of neohesperidin dihydrochalcone and consider its application for the treatment of additional protozoan infections
Toxoplasma gondii (T. gondii) is a cosmopolitan protozoan parasite in humans and animals. It infects about 30 % of the human population worldwide and causes potentially fatal diseases in immunocompromised hosts and neonates. For this study, five English-language databases (ScienceDirect, ProQuest, Web of Science, PubMed, and Scopus) and the internet search engine Google Scholar were searched. This review was accomplished to draw a global perspective of what is known about the pathogenesis of T. gondii and various factors affecting it. Virulence and immune responses can influence the mechanisms of parasite pathogenesis and these factors are in turn influenced by other factors. In addition to the host's genetic background, the type of Toxoplasma strain, the routes of transmission of infection, the number of passages, and different phases of parasite life affect virulence. The identification of virulence factors of the parasite could provide promising insights into the pathogenesis of this parasite. The results of this study can be an incentive to conduct more intensive research to design and develop new anti-Toxoplasma agents (drugs and vaccines) to treat or prevent this infection. In addition, further studies are needed to better understand the key agents in the pathogenesis of T. gondii.
Toxoplasmosis, caused by Toxoplasma gondii, poses risks to vulnerable populations. TgPDCD5, a secreted protein of T. gondii, induces apoptosis through heparan sulfate-mediated endocytosis. The entry mechanism of TgPDCD5 has remained elusive. Here, we present the solution structure of TgPDCD5 as a helical bundle with an extended N-terminal helix, exhibiting molten globule characteristics. NMR perturbation studies reveal heparin/heparan sulfate binding involving the heparan sulfate/heparin proteoglycans-binding motif and the core region, influenced by proline isomerization of P107 residue. The heterogeneous proline recruits a cyclophilin TgCyp18, accelerating interconversion between conformers and regulating heparan/heparin binding. These atomic-level insights elucidate the binary switch’s functionality, expose novel heparan sulfate-binding surfaces, and illuminate the unconventional cellular entry of pathogenic TgPDCD5.
The aim of this study was to estimate the molecular infection prevalence of Toxoplasma gondii in sheep liver tissues destined for human consumption. A total number of 224 liver tissues were collected from slaughtered sheep in Sejnane slaughterhouse (Northwest Tunisia). PCR was used to detect T. gondii DNA in liver tissues followed by phylogenetic analysis of amplicons. The phylogenetic tree was then constructed to compare the partial sequences of the ITS1 gene with GenBank sequences.
The overall molecular prevalence of T. gondii in sheep livers was 25% (56/224). The highest molecular prevalence of T. gondii was recorded in sheep aged of less than one year old (27.3%; 52/190). Infection prevalence was significantly higher in Noire de Thibar breed (33%; 17/51) compared to other breeds (p = 0.023). There were no differences depicted according to sheep’s gender. The T. gondii sequences obtained in the present study (GenBank accession numbers: OR509829 and OR509830) were 98.40-100% homologous to T. gondii sequences published in the GenBank. These results highlight a high level of T. gondii contamination of tissues destined for human consumption. Further studies are needed to improve our knowledge on different genotypes of T. gondii that infect Tunisian sheep population.
Infectious diseases affecting the eye often cause unilateral or asymmetric visual loss in children and people of working age. This group of conditions includes viral, bacterial, fungal and parasitic diseases, both common and rare presentations which, in aggregate, may account for a significant portion of the global visual burden. Diagnosis is frequently challenging even in specialist centres, and many disease presentations are highly regional. In an age of globalisation, an understanding of the various modes of transmission and the geographic distribution of infections can be instructive to clinicians. The impact of eye infections on global disability is currently not sufficiently captured in global prevalence studies on visual impairment and blindness, which focus on bilateral disease in the over-50s. Moreover, in many cases it is hard to differentiate between infectious and immune-mediated diseases. Since infectious eye diseases can be preventable and frequently affect younger people, we argue that in future prevalence studies they should be considered as a separate category, including estimates of disability-adjusted life years (DALY) as a measure of overall disease burden. Numbers of ocular infections are uniquely affected by outbreaks as well as endemic transmission, and their control frequently relies on collaborative partnerships that go well beyond the remit of ophthalmology, encompassing domains as various as vaccination, antibiotic development, individual healthcare, vector control, mass drug administration, food supplementation, environmental and food hygiene, epidemiological mapping, and many more. Moreover, the anticipated impacts of global warming, conflict, food poverty, urbanisation and environmental degradation are likely to magnify their importance. While remote telemedicine can be a useful aide in the diagnosis of these conditions in resource-poor areas, enhanced global reporting networks and artificial intelligence systems may ultimately be required for disease surveillance and monitoring.
The results regarding the prevalence of toxoplasmosis in humans in the city of Iasi during one year, show a rate of 6,6% of cases detected with positive IgM, and 32.7% of cases detected with positive IgG, compared to the prevalence of toxoplasmosis in cats which shows a rate of 0.7% of positive cases detected with positive IgM; which denotes that toxoplasmosis is underdiagnosed in veterinary medicine. A very important role is played by the diagnostic method used. The article deals with a case study, a 1,8-year-old cat with cerebellar ataxia, dysmetria and hypermetria, with moderate opacification of the entire corneal surface, panuveitis, chorioretinitis and corneal edema. Following the paraclinical investigations, the diagnosis of toxoplasmosis was made, using the Welltest Toxoplasma IgG/IgM immunochromatographic test, confirming the acute phase of the disease with positive IgM and negative IgG. Using the molecular detection techniques through qRT PCR, the result was negative, emphasizing the fact that the protozoan Toxoplasma gondii uses the blood as a way of spreading in the body, the relatively short phase that can induce a negative result, despite the presence of severe symptoms. The conclusions emphasize the importance of using a correct diagnostic method, molecular techniques, despite their high sensitivity, are not always recommended. In toxoplasmosis, the recommended diagnostic method is the serological one to detect IgG/IgM antibodies.
Background:
2,4,6-Trichlorophenol (TCP), 2,4,6-tribromophenol (TBP) and 2,4,6-triiodophenol (TIP) are three widely detected trihalophenolic disinfection by-products (DBPs). Previous studies have mainly focused on the carcinogenic risk and developmental toxicity of 2,4,6-trihalophenols. Very little is known about their immunotoxicity in mammals.
Objectives:
We investigated the effects of 2,4,6-trihalophenols on mammalian immunity using a mouse macrophage model infected with bacteria or intracellular parasites and aimed to elucidate the underlying mechanisms from an epitranscriptomic perspective. The identified mechanisms were further validated in human peripheral blood mononuclear cells (PBMCs).
Methods:
The mouse macrophage cell line RAW264.7 and primary mouse peritoneal macrophages were exposed to different concentrations of TCP, TBP, and TIP. The pro-inflammatory marker Ly6C, the survival of the bacterium Escherichia coli (E. coli), and the parasite burden of Toxoplasma gondii (T. gondii) were assessed. Furthermore, the global gene expression profiling of macrophages following exposure to 2,4,6-trihalophenols was obtained through RNA-sequencing (RNA-seq). The effects of 2,4,6-trihalophenols on RNA N6-methyladenosine (m6A) methyltransferases and total RNA m6A levels were evaluated using Western blotting and dot blot, respectively. Transcriptome-wide m6A methylome was analyzed by m6A-seq. In addition, expression of m6A regulators and total RNA m6A levels in human PBMCs exposed to 2,4,6-trihalophenols were detected using quantitative reverse transcriptase polymerase chain reaction and dot blot, respectively.
Results:
Mouse macrophages exposed to TCP, TBP, or TIP had lower expression of the pro-inflammatory marker Ly6C, with a greater difference from control observed for TIP-exposed cells. Consistently, macrophages exposed to such DBPs, especially TIP, were susceptible to infection with the bacterium E. coli and the intracellular parasite T. gondii, indicating a compromised ability of macrophages to defend against pathogens. Intriguingly, macrophages exposed to TIP had significantly greater m6A levels, which correlated with the greater expression levels of m6A methyltransferases. Macrophages exposed to each of the three 2,4,6-trihalophenols exhibited transcriptome-wide redistribution of m6A. In particular, the m6A peaks in genes associated with immune-related pathways were altered after exposure. In addition, differences in m6A were also observed in human PBMCs after exposure to 2,4,6-trihalophenols.
Discussion:
These findings suggest that 2,4,6-trihalophenol exposure impaired the ability of macrophages to defend against pathogens. This response might be associated with notable differences in m6A after exposure. To the best of our knowledge, this study presents the first m6A landscape across the transcriptome of immune cells exposed to pollutants. However, significant challenges remain in elucidating the mechanisms by which m6A mediates immune dysregulation in infected macrophages after 2,4,6-trihalophenol exposure. https://doi.org/10.1289/EHP11329.
"Minimally invasive surgery is constantly improving and breaking grounds due to its benefits such as, fast recovery and less pain. But these procedures need a lot of effort from the surgeon, more than an opened technique, since the focus becomes a monitor and not a directly visible organ. In cats two procedures can be performed for spaying, ovariectomy and ovariohisterectomy. The first one can be performed using a two port laparoscopy technique. This study describes the surgical approach for a laparoscopic two port ovariectomy and emphasizes on the time needed for the procedure, taking into study 8 young healthy short hair cats and a veterinary surgeon with limited experience in laparoscopy, but with some little experience in using the laparoscopic instrumentation. None of the surgeries needed conversion. In one case we observed a wound dehiscence, that healed by secondary healing. The surgeon’s time of surgery improved as the number of cases increased."
Introduction
Toxoplasma gondii is an obligate intracellular protozoan that can infect almost all warm-blooded animals, including humans. Patients with co-infection with toxoplasmosis and HIV have a 30-40% risk of developing toxoplasmosis encephalitis. This study aimed to describe the epidemiology and burden of Toxoplasma gondii in HIV-infected individuals in Iran.
Methods
We searched the five English databases (Science Direct, PubMed, Scopus, Ovid, Embase, and Cochrane) and four Persian databases (Scientific Information Database (SID), Iran Medex, Iran Doc, and Magiran) with the terms of (Toxoplasma gondii OR “toxoplasmosis”) AND (HIV OR “AIDS” OR immunodeficiency OR acquired immune deficiency syndrome) AND (Seroprevalence) AND (Seroepidemiologic Studies) AND (Elisa OR IgG) AND (PCR) AND (Iran) by two authors up to Feb 2021. Studies were included if they investigated people with HIV infection and presented data that allowed us to establish the prevalence of Toxoplasma gondii infection in Iran.
Results
According to the inclusion/exclusion criteria, 15 studies were selected. A total number of 2275 HIV-infected individuals were tested and evaluated for toxoplasmosis from 2005 up to 2018 in different regions of Iran. The weighted overall prevalence of toxoplasmosis in HIV-infected individuals with Elisa was obtained using a random-effects model, which was estimated at 47% (95% CI = 31% – 62%). Also, the Weighted overall prevalence of toxoplasmosis in HIV-infected individuals with PCR was obtained using a random-effects model, which was estimated at 7% (95% CI = 3% – 12%).
Conclusion
According to the results of this study, it can be clearly understood that a large population of HIV patients living in Iran have toxoplasmosis. Therefore, due to the high susceptibility of these groups to toxoplasmosis, healthcare professionals must consider measures such as training in the ways of transmission and prevention of the infection to this high-risk group in order to reduce the risk of infection.
TORCH enfeksiyonları, Toxoplasma gondii, Rubella, Cytomegalovirus (CMV), Herpes Simpleks Virüs ve diğer bazı patojenlerin neden olduğu, anne-fetal bariyeri geçebilen ve potansiyel olarak fetüsün gelişimini olumsuz etkileyebilen bir grup enfeksiyonu ifade etmektedir. Bu çalışmada, doğurganlık çağındaki kadınlarda konjenital enfeksiyonlara neden olma potansiyeline sahip Toksoplazma, Rubella ve CMV’ye karş oluşan antikorların seroprevalansının belirlenmesi amaçlanmıştır. 1 Ocak 2020 ve 1 Aralık 2022 tarihleri arasında laboratuvarımıza anti-Toksoplazma IgM ve IgG, anti-Rubella IgM ve IgG, anti-CMV IgM ve IgG serolojisinin araştırılması amacı ile gönderilen doğurganlık çağındaki 15–49 yaş arası toplam 2155 kadına ait test sonuçları retrospektif olarak incelenmiştir. Hasta serumlarında, IgM ve IgG antikorları Enzyme Linked Fluorescent Assay (ELFA-VIDAS, bioMérieux, Fransa) yöntemi ile tespit edilmiştir. Çalışmamızda anti-Toksoplazma IgM pozitifliği %0,5, anti-Toksoplazma IgG pozitifliği %19,4; anti-Rubella IgM pozitifliği %0,5, anti-Rubella IgG pozitifliği %92,3; anti-CMV IgM pozitifliği %0,5, anti-CMV IgG pozitifliği ise %99,9 olarak tespit edilmiştir. Toxoplazma IgG seropozitifliği ile yaş grubu arasında istatistiksel olarak anlamlı bir farklılık olduğu ve yaşın azalması ile istatistiksel olarak arttığı tespit edilmiştir (p
To determine a cost-minimizing option for congenital toxoplasmosis in the United States.
A decision-analytic and cost-minimization model was constructed to compare monthly maternal serological screening, prenatal treatment, and post-natal follow-up and treatment according to the current French (Paris) protocol, versus no systematic screening or perinatal treatment. Costs are based on published estimates of lifetime societal costs of developmental disabilities and current diagnostic and treatment costs. Probabilities are based on published results and clinical practice in the United States and France. One- and two-way sensitivity analyses are used to evaluate robustness of results. Universal monthly maternal screening for congenital toxoplasmosis with follow-up and treatment, following the French protocol, is found to be cost-saving, with savings of 12, screening is cost-saving for rates of congenital infection above 1 per 10,000 live births. If universal testing generates economies of scale in diagnostic tools-lowering test costs to about $2 per test-universal screening is cost-saving at rates of congenital infection well below the lowest reported rates in the United States of 1 per 10,000 live births.
Universal screening according to the French protocol is cost saving for the US population within broad parameters for costs and probabilities.
Toxoplasma gondii has arisen as an important opportunistic agent especially in the central nervous system and in advanced HIV disease can cause significant morbidity and mortality. This study was carried out to determine the seroprevalence of toxoplasmosis among HIV-positive patients in Iran. Blood samples were collected from 201 HIV-positive patients and anti-toxoplasma antibodies were detected by using conventional ELISA. An antibody titer of >3 IU/ml was considered positive. The majority of studied patients were male (male to female ratio: 5 to 1) with the mean age of 36 ± 1 yrs. The seroprevalence of toxoplasmosis in HIV-positive patients was 49.75%. The mean CD4 count in HIV patients with positive toxoplasma serology was 332.5 ± 22.4 cells/µl. Only 1% of the patients had IgM anti-toxoplasma antibodies and 10% of the patients had clinical toxoplasma encephalitis. The mean CD4 count in this group was 66.4 ± 15.5 cells/µl and there was a significant association between CD4 count and rate of toxoplasma encephalitis (P<0.001). Previous reports suggested that toxoplasma encephalitis could be prevented by appropriate chemoprophylaxis. In view of the relatively high prevalence of toxoplasma infection found among the HIV-infected patients in our study, we suggest that routine screening for toxoplasma should be undertaken for all HIV-infected patients in Iran.
To determine the incidence of congenital toxoplasmosis in Colombian newborns from 19 hospital or maternal child health services from seven different cities of five natural geographic regions (Caribbean, Central, Andean, Amazonia and Eastern).
We collected 15,333 samples from umbilical cord blood between the period of March 2009 to May 2010 in 19 different hospitals and maternal-child health services from seven different cities. We applied an IgM ELISA assay (Vircell, Spain) to determine the frequency of IgM anti Toxoplasma. The results in blood cord samples were confirmed either by western blot and repeated ELISA IgM assay. In a sub-sample of 1,613 children that were negative by the anti-Toxoplasma IgM assay, the frequency of specific anti-Toxoplasma IgA by the ISAGA assay was determined. All children with positive samples by IgM, IgA, clinical diagnosis or treatment during pregnancy were recalled for confirmatory tests after day 10 of life.
61 positive samples for specific IgM (0.39%) and 9 positives for IgA (0.5%) were found. 143 questionnaires were positive for a clinical diagnosis or treatment for toxoplasmosis during pregnancy. 109 out of the 218 children that had some of the criteria for postnatal confirmatory tests were followed. Congenital toxoplasmosis infection was confirmed in 15 children: 7 were symptomatic, and three of them died before the first month of life (20% of lethality). A significant correlation was found between a high incidence of markers for congenital toxoplasmosis and higher mean annual rainfall for the city.
Incidence for congenital toxoplasmosis is significantly different between hospitals or maternal child health services from different cities in Colombia. Mean annual rainfall was correlated with incidence of congenital toxoplasmosis.
Toxoplasmosis, a protozoan disease caused by the coccidian parasite Toxoplasma gondii, is one of the most prevalent parasitic diseases of humans. Although most infections are subclinical and asymptomatic, it has a great importance with respect to immunocompromized hosts and congenitally infected newborns. The diagnosis of T. gondii infection has gained in great interest over the past decades with a wide variety of techniques being investigated from animal inoculation to advanced molecular techniques. This paper reviews and highlights the development and evaluation of polymerase chain reaction in the diagnosis of congenital toxoplasmosis in human population to present the redundant research on it in a chronologically simple approach.
Infection with T. gondii is particularly dangerous for pregnant women as it may lead to the transplacental passage of the parasite. Currently, congenital toxoplasmosis is the second most frequent intrauterine infection. The risk of transmission of T. gondii to the foetus varies throughout the world and ranges from 0.6-1.7/1,000 of pregnant women. The consequences of congenital toxoplasmosis are multifarious. On the basis of current literature review, the authors discuss the epidemiological and clinical aspects of toxoplasmosis in pregnant women, the influence of climatic and environmental factors that may lead to an increase in T. gondii infections in humans, particularly in pregnant women, and the principles of prophylactics against T. gondii infections in those women.
Protozoan foodborne diseases are generally underrecognized. Toxoplasma gondii is the causative agent of toxoplasmosis, one of the most prevalent parasitic infections to humans and domestic animals. The most likely source of T. gondii occurring through food is the consumption of raw or undercooked meat contaminated with tissue cysts. Sporulated T. gondii oocysts, from the feces of infected cats, present in the environment are a potential source of infection. The ingestion of water contaminated with oocysts and the eating of unwashed raw vegetables or fruits were identified as an important risk factor in most epidemiological studies. This review presents information and data to show the importance of T. gondii transmission by foods.
Kotresha D, Rahmah N. Recombinant proteins in the diagnosis of toxoplasmosis. APMIS 2010; 118: 529–42.
Toxoplasma gondii is an important human pathogen with a worldwide distribution. It is primarily of medical importance for pregnant women and immunocompromised patients. Primary infection of the former is often associated with fetal infection, which can lead to abortion or severe neonatal malformation. Immunocompromised patients are at risk of contracting the severe form of the disease that may be fatal. Thus, detection of T. gondii infection with high sensitivity and specificity is crucial in the management of the disease. Toxoplasmosis is generally diagnosed by demonstrating specific immunoglobulin M (IgM) and IgG antibodies to toxoplasma antigens in the patient’s serum sample. Most of the commercially available tests use T. gondii native antigens and display wide variations in test accuracy. Recombinant antigens have great potential as diagnostic reagents for use in assays to detect toxoplasmosis. Thus in this review, we address recent advances in the use of Toxoplasma recombinant proteins for serodiagnosis of toxoplasmosis.
The usefulness of a specific immunoglobulin G (IgG) avidity enzyme-linked immunosorbent assay (ELISA) based on recombinant GRA6 antigen for distinguishing between acute and chronic Toxoplasma infection was investigated. Two sets of serum samples obtained from pregnant women with acute, chronic, or no Toxoplasma infection collected in France and Iran were used. Among the French subjects, 19 of 20 (95%) women who experienced seroconversion during the past 4 months before sampling displayed low-avidity IgG antibodies against GRA6, while all 17 (100%) women with chronic infection had high-avidity antibodies. When the Euroimmun IgG avidity ELISA was used, 15 of 19 (78.9%) recently infected women had low-avidity antibodies, and 20 of 22 (90.9%) women with chronic infection displayed high-avidity antibodies. The results suggested better performance of the GRA6 avidity ELISA than the Euroimmun avidity ELISA for exclusion of a recent infection occurring less than 4 months previously. Similarly, all 35 Iranian women with acute Toxoplasma infection had low-avidity antibodies against GRA6, whereas all 34 women with chronic infection displayed IgG antibodies of high avidity, indicating the value of GRA6 avidity testing for ruling out a recent infection. Avidity tests based on lysed whole-cell Toxoplasma gondii antigen are currently used to exclude recently acquired infections; however, the use of recombinant antigen(s) might improve the diagnostic performance of avidity tests and facilitate the development of more standardized assays.
Although screening for maternal toxoplasmic seroconversion during pregnancy is based on immunodiagnostic assays, the diagnosis of clinically relevant toxoplasmosis greatly relies upon molecular methods. A problem is that this molecular diagnosis is subject to variation of performances, mainly due to a large diversity of PCR methods and primers and the lack of standardization. The present multicentric prospective study, involving eight laboratories proficient in the molecular prenatal diagnosis of toxoplasmosis, was a first step toward the harmonization of this diagnosis among university hospitals in France. Its aim was to compare the analytical performances of different PCR protocols used for Toxoplasma detection. Each center extracted the same concentrated Toxoplasma gondii suspension and tested serial dilutions of the DNA using its own assays. Differences in analytical sensitivities were observed between assays, particularly at low parasite concentrations (<or=2 T. gondii genomes per reaction tube), with "performance scores" differing by a 20-fold factor among laboratories. Our data stress the fact that differences do exist in the performances of molecular assays in spite of expertise in the matter; we propose that laboratories work toward a detection threshold defined for a best sensitivity of this diagnosis. Moreover, on the one hand, intralaboratory comparisons confirmed previous studies showing that rep529 is a more adequate DNA target for this diagnosis than the widely used B1 gene. But, on the other hand, interlaboratory comparisons showed differences that appear independent of the target, primers, or technology and that hence rely essentially on proficiency and care in the optimization of PCR conditions.
This paper reports on the national neonatal screening programme for congenital toxoplasmosis (CT) in Denmark conducted from 1999 to 2007, including background, basis for initiation of screening, methods, results, and finally reasons for the discontinuation of the screening.
A nationwide screening was conducted at Statens Serum Institut, including >98% newborns, and using filter paper eluates (Guthrie card, PKU card) obtained from newborns 5-10 days old. These were analysed for Toxoplasma gondii-specific antibodies (IgM), and if positive, then IgM (ISAGA). Confirmatory serology was performed on children and their mothers (IgM, IgG, IgA, dye test) where infection was suspected, and children with suspected or confirmed CT initiated a 3-month treatment regimen with pyrimethamine, sulfadiazine and folinic acid supplements. Selective cohorts were followed with regard to developmental and clinical outcome.
A total of 100 children were diagnosed with CT in the screening period, and only 2 cases were detected outside of the screening programme. CT prevalence was 1.6 per 10,000 live-born infants. Follow-up studies showed new retinochoroidal lesions in affected children despite treatment.
Screening was terminated August 2007, after it became apparent that no benefit of treatment could be shown. CT was evaluated using a Danish adaptation of the Uniform Screening Panel (ACMG), showing CT as an unlikely candidate for screening today. Whereas results might be comparable with other low-endemic countries with similar strains of T. gondii, neonatal screening and treatment might offer different results in regions with either high prevalence or different strains of T. gondii.
Toxoplasmosis can cause severe ocular and neurological disease. We sought to determine risk factors for Toxoplasma gondii infection in the United States.
We conducted a case-control study of adults recently infected with T. gondii. Case patients were selected from the Palo Alto Medical Foundation Toxoplasma Serology Laboratory from August 2002 through May 2007; control patients were randomly selected from among T. gondii-seronegative persons. Data were obtained from serological testing and patient questionnaires.
We evaluated 148 case patients with recent T. gondii infection and 413 control patients. In multivariate analysis, an elevated risk of recent T. gondii infection was associated with the following factors: eating raw ground beef (adjusted odds ratio [aOR], 6.67; 95% confidence limits [CLs], 2.09, 21.24; attributable risk [AR], 7%); eating rare lamb (aOR, 8.39; 95% CLs, 3.68, 19.16; AR, 20%); eating locally produced cured, dried, or smoked meat (aOR, 1.97; 95% CLs, 1.18, 3.28; AR, 22%); working with meat (aOR, 3.15; 95% CLs, 1.09, 9.10; AR, 5%); drinking unpasteurized goat's milk (aOR, 5.09; 95% CLs, 1.45, 17.80; AR, 4%); and having 3 or more kittens (aOR, 27.89; 95% CLs, 5.72, 135.86; AR, 10%). Eating raw oysters, clams, or mussels (aOR, 2.22; 95% CLs, 1.07, 4.61; AR, 16%) was significant in a separate model among persons asked this question. Subgroup results are also provided for women and for pregnant women.
In the United States, exposure to certain raw or undercooked foods and exposure to kittens are risk factors for T. gondii infection. Knowledge of these risk factors will help to target prevention efforts.
A comparative study of the Toxoplasma IgG(I) and IgG(II) Access (Access I and II, respectively; Beckman Coulter Inc.), AxSYM Toxo IgG (AxSYM; Abbott Diagnostics), Vidas Toxo IgG (Vidas; bioMerieux, Marcy l'Etoile, France), Immulite Toxo IgG (Immulite; Siemens Healthcare Diagnostics Inc.), and Modular Toxo IgG (Modular; Roche Diagnostics, Basel, Switzerland) tests was done with 406 consecutive serum samples. The Toxo II IgG Western blot (LDBio, Lyon, France) was used as a reference technique in the case of intertechnique discordance. Of the 406 serum samples tested, the results for 35 were discordant by the different techniques. Using the 175 serum samples with positive results, we evaluated the standardization of the titrations obtained (in IU/ml); the medians (second quartiles) obtained were 9.1 IU/ml for the AxSYM test, 21 IU/ml for the Access I test, 25.7 IU/ml for the Access II test, 32 IU/ml for the Vidas test, 34.6 IU/ml for the Immulite test, and 248 IU/ml for the Modular test. For all the immunoassays tested, the following relative sensitivity and specificity values were found: 89.7 to 100% for the Access II test, 89.7 to 99.6% for the Immulite test, 90.2 to 99.6% for the AxSYM test, 91.4 to 99.6% for the Vidas test, 94.8 to 99.6% for the Access I test, and 98.3 to 98.7% for the Modular test. Among the 406 serum samples, we did not find any false-positive values by two different tests for the same serum sample. Except for the Modular test, which prioritized sensitivity, it appears that the positive cutoff values suggested by the pharmaceutical companies are very high (either for economical or for safety reasons). This led to imperfect sensitivity, a large number of unnecessary serological follow-ups of pregnant women, and difficulty in determining the serological status of immunosuppressed individuals.
Untreated acute toxoplasmosis among pregnant women can lead to serious sequelae among newborns, including neurological impairment and blindness. In Brazil, the risk of congenital toxoplasmosis (CTox) has not been fully evaluated. Our aim was to evaluate trends in acute toxoplasmosis prevalence from 1998-2005, the incidence of CTox and the rate of mother-to-child transmission (MTCT). A cross-sectional study was undertaken to dentify patients who fit the criteria for acute toxoplasmosis during pregnancy. Exposed newborns were included in a historical cohort, with a median follow-up time of 11 months, to establish definite diagnosis of CTox. Diagnoses for acute infection in pregnancy and CTox were based on European Research Network on Congenital Toxoplasmosis criteria. In 41,112 pregnant women, the prevalence of acute toxoplasmosis was 4.8/1,000 women. The birth prevalence of CTox was 0.6/1,000 newborns [95% confidence interval (CI): 0.4-0.9]. During the follow-up study, 12 additional cases were detected, increasing the CTox rate to 0.9/1,000 newborns (95% CI: 0.6-1.3). Among the 200 newborns exposed to Toxoplasma gondii,there were 37 babies presenting diagnostic criteria of CTox, leading to an MTCT rate of 18.5% (95% CI: 13.4-24.6%). The additional cases identified during follow-up reinforce the need for serological monitoring during the first year of life, even in the absence of evidence of congenital infection at birth.
Evidence that prevention, diagnosis and treatment of toxoplasmosis is beneficial developed as follows: anti-parasitic agents abrogate Toxoplasma gondii tachyzoite growth, preventing destruction of infected, cultured, mammalian cells and cure active infections in experimental animals, including primates. They treat active infections in persons who are immune-compromised, limit destruction of retina by replicating parasites and thereby treat ocular toxoplasmosis and treat active infection in the fetus and infant. Outcomes of untreated congenital toxoplasmosis include adverse ocular and neurologic sequelae described in different countries and decades. Better outcomes are associated with treatment of infected infants throughout their first year of life. Shorter intervals between diagnosis and treatment in utero improve outcomes. A French approach for diagnosis and treatment of congenital toxoplasmosis in the fetus and infant can prevent toxoplasmosis and limit adverse sequelae. In addition, new data demonstrate that this French approach results in favorable outcomes with some early gestation infections. A standardized approach to diagnosis and treatment during gestation has not yet been applied generally in the USA. Nonetheless, a small, similar experience confirms that this French approach is feasible, safe, and results in favorable outcomes in the National Collaborative Chicago-based Congenital Toxoplasmosis Study cohort. Prompt diagnosis, prevention and treatment reduce adverse sequelae of congenital toxoplasmosis.
Development of vaccines against Toxoplasma gondii infection in humans is of high priority, given the high burden of disease in some areas of the world like South America, and the lack of effective drugs with few adverse effects. Rodent models have been used in research on vaccines against T. gondii over the past decades. However, regardless of the vaccine construct, the vaccines have not been able to induce protective immunity when the organism is challenged with T. gondii, either directly or via a vector. Only a few live, attenuated T. gondii strains used for immunization have been able to confer protective immunity, which is measured by a lack of tissue cysts after challenge. Furthermore, challenge with low virulence strains, especially strains with genotype II, will probably be insufficient to provide protection against the more virulent T. gondii strains, such as those with genotypes I or II, or those genotypes from South America not belonging to genotype I, II or III. Future studies should use animal models besides rodents, and challenges should be performed with at least one genotype II T. gondii and one of the more virulent genotypes. Endpoints like maternal-foetal transmission and prevention of eye disease are important in addition to the traditional endpoint of survival or reduction in numbers of brain cysts after challenge.
Performance variation among PCR systems in detecting Toxoplasma gondii has been extensively reported and associated with target genes, primer composition, amplification parameters, treatment during pregnancy, host genetic susceptibility and genotypes of different parasites according to geographical characteristics.
A total of 467 amniotic fluid samples from T. gondii IgM- and IgG-positive Brazilian pregnant women being treated for 1 to 6 weeks at the time of amniocentesis (gestational ages of 14 to 25 weeks).
One nested-B1-PCR and three one-round amplification systems targeted to rDNA, AF146527 and the B1 gene were employed.
Of the 467 samples, 189 (40.47%) were positive for one-round amplifications: 120 (63.49%) for the B1 gene, 24 (12.69%) for AF146527, 45 (23.80%) for both AF146527 and the B1 gene, and none for rDNA. Fifty previously negative one-round PCR samples were chosen by computer-assisted randomization analysis and re-tested (nested-B1-PCR), during which nine additional cases were detected (9/50 or 18%).
The B1 gene PCR was far more sensitive than the AF146527 PCR, and the rDNA PCR was the least effective even though the rDNA had the most repetitive sequence. Considering that the four amplification systems were equally affected by treatment, that the amplification conditions were optimized for the target genes and that most of the primers have already been reported, it is plausible that the striking differences found among PCR performances could be associated with genetic diversity in patients and/or with different Toxoplasma gondii genotypes occurring in Brazil.
The use of PCR for the diagnosis of fetal Toxoplasma infections in Brazil should be targeted to the B1 gene when only one gene can be amplified, preferably by nested amplification with primers B22/B23.
Determination of the avidity of immunoglobulin G (IgG) directed against a specific marker has become an established diagnostic tool for identifying or excluding acute infections with pathogens. A novel assay format termed AVIcomp (avidity competition based on mass action) circumventing the conventional chaotropic format has been developed for determination of the avidity of marker-specific IgG in patient specimens. Its applications for cytomegalovirus (CMV) and Toxoplasma gondii are presented. Specific high-avidity IgG from the patient specimen is selectively blocked using a soluble antigen in a sample pretreatment reagent, and the amount of remaining specific low-avidity IgG is determined relative to that in an untreated control. The comparison of the conventional chaotropic format, represented by the Radim CMV IgG Avidity assay, and the newly developed AVIcomp method, as exemplified by the Architect CMV IgG Avidity assay, on blood drawn within 4 months after seroconversion revealed a sensitivity of 100% (97.3% by an alternative calculation) for the AVIcomp format versus 87.5% (75.7% by an alternative calculation) for the chaotropic avidity assay. The specificity on 312 CMV IgG reactive and CMV IgM nonreactive specimens from pregnant women was 100% for the AVIcomp assay and 99.7% for the conventional avidity assay. The Architect Toxo IgG Avidity assay showed an agreement of 97.2% with the bioMérieux Vidas Toxo IgG Avidity Assay employing chaotropic reagents. These performance data suggest that the AVIcomp format shows superior sensitivity and equivalent specificity for the determination of IgG avidity to assays based on the chaotropic method and that the AVIcomp format may also be applicable to other disease states.
An unusual assay was developed for the serologic diagnosis of recent primary infection by Toxoplasma gondii. This test measures the antigen-binding avidity of toxoplasma-specific IgG antibodies. Serum samples from 5 patients with
recent primary toxoplasma infection were compared with those from 21 subjects with preexisting toxoplasma immunity. Patients
with primary infection exhibited a low avidity of toxoplasma-specific IgG, which persisted for several months after the onset
of symptoms of toxoplasmosis. In contrast, all subjects with past immunity had a high avidity of toxoplasma-IgG. This IgG
avidity assay should assist in the diagnosis of acquired toxoplasmosis and may be used to identify pregnancies that are at
risk for congenital toxoplasmosis.
The paper studies impacts of particular toxoplasmosis risk factors (consumption of raw meat and contact with cats), their interactions, and their relationship with the personality of the subjects. Among 243 men and 343 women the frequency of subjects with antitoxoplasma immunity was 26.6% and 21.6%, respectively. The association of antitoxoplasma immunity (assessed by the toxoplasmin skin test) with the two risk factors was estimated by log-linear analysis. Reported contact with cats has no influence on the probability of having antitoxoplasma immunity (P = 0.23) while the consumption of raw meat increased this probability (P = 0.0008). Very strong positive association between the contact with cats and the raw meat consumption was found among subjects without toxoplasmosis (P = 0.0028), suggesting that among these persons some subjects either incorrectly assessed their exposition to the risk factors or provided false data during the interview. The results of logistic regression suggest that the contact with cat and the consumption of raw meat are associated with particular personality traits. However, these traits differ from those associated with antitoxoplasma immunity suggesting that the correlation between antitoxoplasma immunity and consumption of raw meat reflects epidemiological importance of the raw meat rather than a correlation of both factors (raw meat consumption and probability of acquiring toxoplasmosis) with the subjects personality.
This authoritative and comprehensive account looks at the re-emergence of toxoplasmosis as a significant and potentially fatal infection. A team of acknowledged international experts review the latest diagnostic techniques, and the management of infection in pregnant women, neonates, the eye, transplant and other immunosuppressed patients and those with AIDS. The contentious issue of the role of screening during pregnancy and in the new-born is covered in depth. The introductory chapters on biology, immunology and epidemiology of the infection provide essential background to understanding the clinical disease. The full range of treatment strategies are presented in an easily accessible form. The natural history and life cycle of the causative organism, Toxoplasma gondii, provide a fascinating insight into one of the most successful parasites on earth. Although the burden of this disease varies greatly from country to country, it remains a global public health problem which affects about one billion individuals.
Immunization with nucleic acids can induce both CD4+ and CD8+ mediated immune responses. Because both types of responses are important in conferring immunity to T.qondii infections, immunization with a plasmid capable of expressing antigen has the potential to induce protective immunity. To assess the feasibility of achieving immunity to T. qondii we performed vaccinations using a cDNA construct which contained the coding sequence for the mature protein of the P30 surface antigen under control of the immediate early promoter of CMV. Transfection of rhabdomyosarcoma cells with the plasmid led to the secretion of a 30kDa protein immunoreactive with antibody to P30. Sera of mice injected with the recombinant plasmid were positive against T. qondii by ELISA and immunofluorescence. Both intramuscular and Gene Gun injection of mice with the plasmid led to production of antibody against P30. Western analysis revealed that sera from positive mice reacted with a band of approximately 30kDa. These results suggest that nucleic acid vaccination may offer an effective means to obtain immunization against T. gondii.
Sir.—The article by Koskiniemi et al¹ that appeared in the June 1989 issue of AJDC illustrates the great need for controlled data concerning optimal means to diagnose and treat congenital toxoplasmosis. We are conducting a randomized, prospective study to evaluate treatment and outcome of patients with congenital toxoplasmosis. This national collaborative study is supported by the National Institutes of Allergy and Infectious Diseases, the March of Dimes, and the Food and Drug Administration, Orphan Drugs Division.
Patients are stratified based on severity of their disease. They are then randomized to one of three treatment regimens, which include pyrimethamine, sulfonamides, folinic acid, and spiramycin.
To ensure uniform evaluation, patients are evaluated at the study center in Chicago, Ill, at ages 0 to 2 months and 1, 3.5, 5.5, 8, and 15 years. Evaluation includes assessments of the patient's immunologic response to Toxoplasma gondii and assessments by specialists in pediatric
This authoritative and comprehensive account looks at the re-emergence of toxoplasmosis as a significant and potentially fatal infection. A team of acknowledged international experts review the latest diagnostic techniques, and the management of infection in pregnant women, neonates, the eye, transplant and other immunosuppressed patients and those with AIDS. The contentious issue of the role of screening during pregnancy and in the new-born is covered in depth. The introductory chapters on biology, immunology and epidemiology of the infection provide essential background to understanding the clinical disease. The full range of treatment strategies are presented in an easily accessible form. The natural history and life cycle of the causative organism, Toxoplasma gondii, provide a fascinating insight into one of the most successful parasites on earth. Although the burden of this disease varies greatly from country to country, it remains a global public health problem which affects about one billion individuals.
Objective
To valide a multiplex polymerase chain reaction (PCR) assay capable of simultaneously screening vitreous biopsy specimens for a panel of common pathogens in posterior uveitis.
Methods
A multiplex PCR assay using novel primer sets for cytomegalovirus (CMV), herpes simplex virus (HSV), varicella zoster virus (VZV), and Toxoplasma gondii was developed. The sensitivity of the assay was determined for purified pathogen DNA. Twenty-one vitreous specimens from patients with posterior uveitis were tested by both multiplex and monoplex PCR.
Results
Fewer than 10 genomes of VZV and fewer than 100 genomes of HSV, CMV, and T gondii could be detected using the new primer sets. When used in multiplex, the assay lost less than 1 log of sensitivity. Monoplex PCR detected pathogen DNA in 18 of 21 patient samples; multiplex PCR detected pathogen DNA in 15 of the 18 samples positive by monoplex PCR. None of 10 negative control samples were positive for pathogen DNA.
Conclusions
Multiplex PCR has adequate sensitivity to simultaneously screen a substantial differential diagnosis for posterior uveitis in a single reaction, without loss of specificity. This assay may reduce the time and cost involved in PCR-based molecular diagnostics of infectious pathogens.
Clinical Relevance
Mutiplex PCR may allow rapid diagnosis of infectious posterior uveitis.
This paper reviews the domestic and foreign literatures regarding molecular diagnosis of toxoplasmosis. The nucleic acid molecule hybridization and Toxoplasma gondii gene sequences for polymerase chain reaction (PCR), common and conventional PCR, nested PCR, real-time quantitative PCR, immune PCR, in-situ PCR, loop-mediated isothermal amplification technology are introduced.
Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is one of the most common parasitic infections in humans. Primary infection in pregnant women can be transmitted to the fetus leading to miscarriage or congenital toxoplasmosis. Carefully designed nationwide seroprevalence surveys and case-control studies of risk factors conducted primarily in Europe and America, have shaped our view of the global status of maternal and congenital infection, directing approaches to disease prevention. However, despite encompassing 1 in 5 of the world's population, information is limited on the status of toxoplasmosis in China, partly due to the linguistic inaccessibility of the Chinese literature to the global scientific community. By selection and analysis of studies and data, reported within the last 2 decades in China, this review summarizes and renders accessible a large body of Chinese and other literature and aims to estimate the seroprevalence in Chinese pregnant women. It also reviews the prevalence trends, risk factors, and clinical manifestations. The key findings are (1) the majority of studies show that the overall seroprevalence in Chinese pregnant women is less than 10%, considerably lower than a recently published global analysis; and (2) the few available appropriate studies on maternal acute infection suggested an incidence of 0·3% which is broadly comparable to studies from other countries.
Toxoplasmosis is a common congenital infection. It does not usually produce recognizable signs of infection at birth so most infected newborns are not detected by routine clinical examination and remain untreated. Infected children without clinical symptoms should nonetheless be identified and treated as early as possible. Serological diagnosis of congenital toxoplasmosis is quite difficult. The aim of this study was to evaluate the utility of Western blot for the diagnosis of congenital toxoplasmosis. We compared the immunological profiles of mothers and children to differentiate between passively transmitted maternal antibodies and antibodies synthesized by the infants in the first three months of life. The method enabled us to diagnose congenital toxoplasmosis in cases in which the infection had not been detected by classical serology techniques.
Long-term evolution of congenital toxoplasmosis is not documented. We assessed the outcome of treated congenital toxoplasmosis in a cohort of adult individuals who had undergone ante- and postnatal treatment to provide information for pediatricians and parents on the evolution of the disease.
We conducted a questionnaire study on 126 adults with congenital toxoplasmosis (mean age: 22.2 years; age range: 18-31 years) monitored regularly until the time of inclusion. The main outcome measures were quality of life (Psychological General Well-Being Index) and visual function (VF14 questionnaire), and the outcomes were correlated with disease-specific factors.
Of the 102 patients (80.9%) who were finally included in the study, 12 (11.8%) presented neurologic effects and 60 (58.8%) manifested ocular lesions; in the latter category, 13 individuals (12.7%) had reduced visual function. The overall global quality-of-life score (74.7 ± 14.2) was close to the expected normal range for the general population (73.7 ± 15.3). Overall, visual function was only slightly impaired (M = 97.3; 95% confidence interval, 95.8-98.8). Although disease-independent critical life circumstances were associated with a reduced Psychological General Well-Being Index, this index was not influenced by any of the clinical characteristics of congenital toxoplasmosis. Neurologic pathologies, reduced visual acuity, foveal location of the retinal lesion, and squinting contributed to decreased visual function at follow-up.
Our data reveal that treated congenital toxoplasmosis has little effect on the quality of life and visual function of the affected individuals. These encouraging findings may help to alleviate the anxiety of affected individuals and their parents.
Clin Microbiol Infect 2010; 16: 363–368
Toxoplasma gondii can be responsible for congenital toxoplasmosis leading to mild or severe sequelae, and for life-threatening infections in immunocompromised hosts. A new 5′-nuclease real-time PCR assay that targets the 300-fold repeated AF146527 DNA sequence (TaqMan-AF-PCR) has been developed and its performance for diagnosis of toxoplasmosis and treatment follow-up has been assessed. A retrospective analysis was first performed with 144 clinical specimens previously analysed for the presence of T. gondii DNA by a PCR–ELISA assay that targets the B1 gene of T. gondii (B1-PCR–ELISA). Fifteen samples, all from patients with clinically proven toxoplasmosis, were negative according to B1-PCR–ELISA and positive according to TaqMan-AF-PCR. A prospective analysis was then performed with 203 consecutive clinical specimens received at the laboratory of Parasitology of Saint-Louis Hospital during a 4-month period. The diagnosis of toxoplasmosis in two patients was made according to the TaqMan-AF-PCR whereas the B1-PCR–ELISA failed to make diagnosis. Additionally, iterative samples from a patient with cerebral and disseminated toxoplasmosis, already tested using a B1 real-time PCR assay, were tested using the TaqMan-AF-PCR and a Light Cycler real-time PCR assay targeting the same repetitive AF146527 sequence (LC-AF-PCR). Detection was achieved with the TaqMan-AF-PCR, with a mean gain of 7.1 and 3.3 amplification cycles when compared with the B1 real-time PCR and the LC-AF-PCR, respectively. This study demonstrates the higher sensitivity of the 5′-nuclease real-time PCR assay developed for the AF146527 DNA sequence and confirms the interest of using this highly repeated target to improve the diagnosis of toxoplasmosis.