[Show abstract][Hide abstract] ABSTRACT: Mycobacterium leprae infects macrophages and Schwann cells inducing a gene expression program to facilitate its replication and progression to disease. MicroRNAs (miRNAs) are key regulators of gene expression and could be involved during the infection. To address the genetic influence of miRNAs in leprosy, we enrolled 1,098 individuals and conducted a case-control analysis in order to study four miRNAs genes containing single nucleotide polymorphism (miRSNP). We tested miRSNP-125a (rs12975333 G.T), miRSNP-223 (rs34952329 *.T), miRSNP-196a-2 (rs11614913 C.T) and miRSNP-146a (rs2910164 G.C). Amongst them, miRSNP-146a was the unique gene associated with risk to leprosy per se (GC OR = 1.44, p = 0.04; CC OR = 2.18, p = 0.0091). We replicated this finding showing that the C-allele was over-transmitted (p = 0.003) using a transmission-disequilibrium test. A functional analysis revealed that live M. leprae (MOI 100:1) was able to induce miR-146a expression in THP-1 (p,0.05). Furthermore, pure neural leprosy biopsies expressed augmented levels of that miRNA as compared to biopsy samples from neuropathies not related with leprosy (p = 0.001). Interestingly, carriers of the risk variant (C-allele) produce higher levels of mature miR-146a in nerves (p = 0.04). From skin biopsies, although we observed augmented levels of miR-146a, we were not able to correlate it with a particular clinical form or neither host genotype. MiR-146a is known to modulate TNF levels, thus we assessed TNF expression (nerve biopsies) and released by peripheral blood mononuclear cells infected with BCG Moreau. In both cases lower TNF levels correlates with subjects carrying the risk C-allele, (p = 0.0453 and p = 0.0352; respectively), which is consistent with an immunomodulatory role of this miRNA in leprosy.
[Show abstract][Hide abstract] ABSTRACT: Mycobacterium leprae and Mycobacterium tuberculosis antimicrobial resistance has been followed with great concern during the last years, while the need for new drugs able to control leprosy and tuberculosis, mainly due to XDR-TB, is pressing. Our group has recently described that M. leprae is able to induce lipid body biogenesis and cholesterol accumulation in macrophages and Schwann cells, facilitating its viability and replication. Considering these previous results, we investigated the efficacy of two statins on the intracellular viability of mycobacteria within the macrophage, and atorvastatin effect on BALB/c mice M. leprae infection. We observed that intracellular mycobacteria viability decreased markedly after incubation with both statins, but atorvastatin showed the best inhibitory effect when combined with rifampin. Using Shepard's model we observed atorvastatin efficacy in control M. leprae and inflammatory infiltrate in the BALB/c footpad, in a serum cholesterol level dependent way. We conclude that statins contribute to macrophage-bactericidal activity against M. bovis, M. leprae and M. tuberculosis. It is likely that statins association with the actual multidrug therapy could effectively reduce mycobacteria viability and tissue lesion in Leprosy and Tuberculosis patients, although epidemiological studies are still needed for confirmation.
Antimicrobial Agents and Chemotherapy 07/2014; · 4.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We synthesized a series of novel dapsone-thalidomide hybrids (3a-i) by molecular hybridization and evaluated their potential for the treatment of type 2 leprosy reactions. All of the compounds had analgesic properties. Compounds 3c and 3h were the most active antinociceptive compounds and reduced acetic acid-induced abdominal constrictions by 49.8% and 39.1%, respectively. The hybrid compounds also reduced tumor necrosis factor-α levels in lipopolysaccharide-stimulated L929 cells. Compound 3i was the most active compound; at concentrations of 15.62 and 125μM, compound 3i decreased tumor necrosis factor-α levels by 86.33% and 87.80%, respectively. In nude mice infected with Mycobacterium leprae in vivo, compound 3i did not reduce the number of bacilli compared with controls. Compound 3i did not have mutagenic effects in Salmonella typhimurium strains TA100 and TA102, with or without metabolic activation (S9 mixture). Our results indicate that compound 3i is a novel lead compound for the treatment of type 2 leprosy reactions.
[Show abstract][Hide abstract] ABSTRACT: We recently showed that Mycobacterium leprae (ML) is able to induce lipid droplet formation in infected macrophages. We herein confirm that cholesterol (Cho) is one of the host lipid molecules that accumulates in ML-infected macrophages and investigate the effects of ML on cellular Cho metabolism responsible for its accumulation. The expression levels of LDL receptors (LDL-R, CD36, SRA-1, SR-B1, and LRP-1) and enzymes involved in Cho biosynthesis were investigated by qRT-PCR and/or Western blot and shown to be higher in lepromatous leprosy (LL) tissues when compared to borderline tuberculoid (BT) lesions. Moreover, higher levels of the active form of the sterol regulatory element binding protein (SREBP) transcriptional factors, key regulators of the biosynthesis and uptake of cellular cholesterol, were found in LL skin biopsies. Functional in vitro assays confirmed the higher capacity of ML-infected macrophages to synthesize Cho and sequester exogenous LDL-Cho. Notably, Cho co-localized to ML-containing phagosomes, and Cho metabolism impairment, through either de novo synthesis inhibition by statins or depletion of exogenous Cho, decreased intracellular bacterial survival. These findings highlight the importance of metabolic integration between the host and bacteria to leprosy pathophysiology, opening new avenues for novel therapeutic strategies to leprosy.
[Show abstract][Hide abstract] ABSTRACT: Leprosy, caused by Mycobacterium leprae, is an important infectious disease that is still endemic in many countries around the world, including Brazil. There are currently no known methods for growing M. leprae in vitro, presenting a major obstacle in the study of this pathogen in the laboratory. Therefore, the maintenance and growth of M. leprae strains are preferably performed in athymic nude mice (NU-Foxn1(nu)). The laboratory conditions for using mice are readily available, easy to perform, and allow standardization and development of protocols for achieving reproducible results. In the present report, we describe a simple protocol for purification of bacilli from nude mouse footpads using trypsin, which yields a suspension with minimum cell debris and with high bacterial viability index, as determined by fluorescent microscopy. A modification to the standard method for bacillary counting by Ziehl-Neelsen staining and light microscopy is also demonstrated. Additionally, we describe a protocol for freezing and thawing bacillary stocks as an alternative protocol for maintenance and storage of M. leprae strains.
[Show abstract][Hide abstract] ABSTRACT: Angiogenesis and lymphangiogenesis are the processes of neovascularization that evolve from preexisting blood and lymphatic vessels. There are few studies on angiogenesis and none on lymphangiogenesis in leprosy. Thus, the role of neovascularization in the pathophysiological mechanisms of the disease was studied across the spectrum of leprosy, its reactional states and its residual lesions.
Seventy-six biopsies of leprosy skin lesions and seven healthy controls were selected. Fifty-five serum samples were used for the detection of CD105 by ELISA. Histological sections were stained with antibodies against CD31 (blood and lymphatic vessels), D2-40/podoplanin (lymphatic vessels), and CD105/endoglin (neovessels). Microvessels were counted in 100 high-power fields (400x) and the number of vessels was evaluated in relation to the extension of the inflammatory infiltrate (0-3), to the bacillary index (0-6) and to the clinical forms. Angiogenesis, as marked by CD31 and CD105, was observed across the leprosy spectrum, compared with the controls. Additionally, there was a positive correlation between these markers with extension of the infiltrate (p <0.0001). For D2/40, lymphangiogenesis was observed in the tuberculoid form (p <0.0001). There was no statistical significance for values of CD105 detected in plasma by ELISA.
Angiogenesis is present across the spectrum of leprosy and in its reactional forms. The increase in the number of vessels, as detected by CD31 and CD105 staining, is related to the extension of the inflammatory infiltrate. Samples from reactional lesions have a higher number of CD31+ and CD105+ stained vessels, which indicates their involvement in the pathophysiological mechanisms of the reactional states. The regression of lesions is accompanied by the regression of neovascularization. Drugs inhibiting angiogenesis may be relevant in the treatment of leprosy, in addition to multidrugtherapy, and in the prevention of the development of reactions.
PLoS ONE 09/2013; 8(9):e74651. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Herein, we performed microarray experiments in Schwann cells infected with live M. leprae and identified novel differentially expressed genes (DEG) in M. leprae infected cells. Also, we selected candidate genes associated or implicated with leprosy in genetic studies and biological experiments. Forty-seven genes were selected for validation in two independent types of samples by multiplex qPCR. First, an in vitro model using THP-1 cells was infected with live Mycobacterium leprae and M. bovis bacillus Calmette-Guérin (BCG). In a second situation, mRNA obtained from nerve biopsies from patients with leprosy or other peripheral neuropathies was tested. We detected DEGs that discriminate M. bovis BCG from M. leprae infection. Specific signatures of susceptible responses after M. leprae infection when compared to BCG lead to repression of genes, including CCL2, CCL3, IL8 and SOD2. The same 47-gene set was screened in nerve biopsies, which corroborated the down-regulation of CCL2 and CCL3 in leprosy, but also evidenced the down-regulation of genes involved in mitochondrial metabolism, and the up-regulation of genes involved in lipid metabolism and ubiquitination. Finally, a gene expression signature from DEG was identified in patients confirmed of having leprosy. A classification tree was able to ascertain 80% of the cases as leprosy or non-leprous peripheral neuropathy based on the expression of only LDLR and CCL4. A general immune and mitochondrial hypo-responsive state occurs in response to M. leprae infection. Also, the most important genes and pathways have been highlighted providing new tools for early diagnosis and treatment of leprosy.
PLoS ONE 06/2013; 8(6):e64748. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Overpopulation of urban areas results from constant migrations that cause disordered urban growth, constituting clusters defined as sets of people or activities concentrated in relatively small physical spaces that often involve precarious conditions. Aim. Using residential grouping, the aim was to identify possible clusters of individuals in São José do Rio Preto, Sao Paulo, Brazil, who have or have had leprosy. Methods. A population-based, descriptive, ecological study using the MapInfo and CrimeStat techniques, geoprocessing, and space-time analysis evaluated the location of 425 people treated for leprosy between 1998 and 2010. Clusters were defined as concentrations of at least 8 people with leprosy; a distance of up to 300 meters between residences was adopted. Additionally, the year of starting treatment and the clinical forms of the disease were analyzed. Results. Ninety-eight (23.1%) of 425 geocoded cases were located within one of ten clusters identified in this study, and 129 cases (30.3%) were in the region of a second-order cluster, an area considered of high risk for the disease. Conclusion. This study identified ten clusters of leprosy cases in the city and identified an area of high risk for the appearance of new cases of the disease.
The Scientific World Journal 01/2013; 2013:219143. · 1.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Leprosy in children younger than 15 years old is correlated with recent disease and active foci of trans-mission in the community, reflecting the efficiency of local control programmes. In the state of Pará (PA), in the Brazilian Amazon Region, leprosy is hyperendemic in this age group. This state had an annual case detec-tion rate of 20.4/100,000 people in 2008, which is much higher than the Brazilian average of 5.8/100,000 people (MS/SVS 2009), indicating that Mycobacterium leprae is circulating amongst the children in PA. Furthermore, in highly endemic areas, the prevalence of previously un-diagnosed leprosy in the general population is six times higher than the registered prevalence (Moet et al. 2008). In Brazil, the primary health service is responsible for diagnosing leprosy, finding active cases of leprosy, tracing the patients' contacts, treating leprosy and pre-venting disability in the people affected by leprosy, but only 42% of the total population of PA is covered by these services (Department of Health Care/Depart-ment of Primary Care 2012 -dab.saude.gov.br/histori-co_cobertura_sf.php). This scenario suggests that there may be many patients with undiagnosed leprosy in PA who are perpetuating the transmission of the bacillus. Additionally, because of the long incubation period of M. leprae, more leprosy patients (LPs) are expected to emerge in the coming decades. The diagnosis of leprosy is based primarily on a clini-cal examination and there is no laboratory test that detects all forms of leprosy. Because of the isolation and char-acterisation of phenolic glycolipid-I (PGL-I) (Hunter & Brennan 1981), a species-specific antigen from the M. leprae cell wall, various studies have demonstrated that serology could potentially be used to detect antibodies against PGL-I to classify patients for treatment purposes, monitor cases, identify the risk of relapse and identify the household contacts (HHCs) of LPs who are at a higher risk of contracting the disease than the general public (Moura et al. 2008). A positive test for anti-PGL-I is associated with an 8.6-fold higher risk of leprosy in HHCs and a 4.4-fold higher risk in non-contacts (Brasil et al. 2003). Some studies have shown that subclinical infections with M. leprae are much more common than overt disease in endemic communities (Godal & Negassi 1973, Abe et al. 1990, Barreto et al. 2011) and that anti-PGL-I sero-positivity is a marker of subclinical infection (Baumgart et al. 1993, Lobato et al. 2011). Van Beers et al. (1999) in-dicated that the seropositivity rates amongst school chil-dren (SC) may reflect leprosy incidence. Seroprevalence may be an appropriate indicator of the magnitude of the burden of leprosy in a selected area. Therefore, screening to determine the seroepidemiol-ogy of anti-PGL-I in hyperendemic areas may be useful Financial support: CNPq (Neglected Diseases 576425/2008-7, schol-arship for CGS), FAPESPA, SESPA, UFPA + Corresponding author:
Memórias do Instituto Oswaldo Cruz 12/2012; 107(Suppl. I):60-67. · 1.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Jorge Lobo's disease is a cutaneous and subcutaneous mycosis that affects patients in the Amazon region. The number of patients is relatively small, but the real situation of the disease as public health problem is not known, because Jorge Lobo's disease is not a notifiable disease. This study aims to report the clinical evolution in patients affected and to determine the prevalence and areas of occurrence of the disease. A retrospective study was carried out based on the analysis of the clinical records, which included a collection of photographs of patients in the Department of Sanitary Dermatology, in Rio Branco, and patients seen in the interior of the state. In a decade, in Rio Branco, 249 cases of the disease were reported, 30 were females and 219 males. Of these patients, 153 had localized lesions, 94 of them were on one ear, 55 had multifocal lesions and 41 had disseminated lesions. The average time between the onset of symptoms and diagnosis was 19 years. The average age at the time of diagnosis was 53 years, and ages ranged from 14 to 96 years.
Revista do Instituto de Medicina Tropical de São Paulo 10/2010; 52(5):273-8. · 0.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Procedures involving the use of Mycobacterium leprae and Lacazia loboi, uncultivated organisms, depend on the collection of material from the lesions of patients or experimental animals. This study compared fine-needle aspiration (FNA) and skin biopsy methods for obtaining bacilli and fungal cells to experimentally infect animals.
Lepromas from one armadillo and one enlarged footpad of a mouse previously inoculated with L. loboi were submitted to FNA and biopsy. Materials collected were processed for inoculation in mice.
Acid-fast bacilli (AFB) collected by two FNA procedures yielded 7.2×10(7) and 5.3×10(6) AFB/ml and biopsies yielded 1.58×10(8) and 3.5×10(8) AFB/ml from each leproma. Yeast-like cells of L. loboi collected by FNA yielded 1.0×10(6) fungal cells/ml and biopsy 1.0×10(7) fungal cells/ml. After 8 months, inoculated animals were sacrificed and the inoculated footpads submitted to histopathological examination and counting of AFB and fungal cells. The results obtained by the two methods were comparable for both microorganisms.
Biopsy may be replaced by FNA during harvesting of material for different purposes, especially for experimental inoculation of mice in leprosy and Jorge Lobo's disease, with the advantage of FNA being a simpler, less invasive, and less costly method.
International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 02/2010; 14 Suppl 3:e49-53. · 2.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Leprosy is still a worldwide public health problem. Brazil and India show the highest prevalence rates of the disease. Natural infection of armadillos Dasypus novemcinctus with Mycobacterium leprae has been reported in some regions of the United States. Identification of bacilli is difficult, particularly due to its inability to grow in vitro. The use of molecular tools represents a fast and sensitive alternative method for diagnosis of mycobacteriosis. In the present study, the diagnostic methods used were bacilloscopy, histopathology, microbiology, and PCR using specific primers for M. leprae repetitive sequences. PCR were performed using genomic DNA extracted from 138 samples of liver, spleen, lymph nodes, and skin of 44 D. novemcinctus, Euphractus sexcinctus, Cabassous unicinctus, and C. tatouay armadillos from the Middle Western region of the state of São Paulo and from the experimental station of Embrapa Pantanal, located in Pantanal da Nhecolândia of Mato Grosso do Sul state. Also, the molecular analysis of 19 samples from internal organs of other road killed species of wild animals, such as Nasua nasua (ring-tailed coati), Procyon cancrivoros (hand-skinned), Cerdocyon thous (dog-pity-bush), Cavia aperea (restless cavy), Didelphis albiventris (skunk), Sphigurrus spinosus (hedgehog), and Gallictis vittata (ferret) showed PCR negative data. None of the 157 analyzed samples had shown natural mycobacterial infection. Only the armadillo inoculated with material collected from untreated multibacillary leprosy patient presented PCR positive and its genomic sequencing revealed 100% identity with M. leprae. According to these preliminary studies, based on the used methodology, it is possible to conclude that wild mammals seem not to play an important role in the epidemiology of leprosy in the Middle Western region of the São Paulo state and in the Pantanal of Mato Grosso do Sul state.
The Brazilian journal of infectious diseases: an official publication of the Brazilian Society of Infectious Diseases 01/2010; 14(1):47-53. · 1.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Several pathogens that cause important zoonotic diseases have been frequently associated with armadillos and other xenarthrans. This mammal group typically has evolved on the South American continent and many of its extant species are seriously threatened with extinction. Natural infection of armadillos with Paracoccidioides brasiliensis in hyperendemic areas has provided a valuable opportunity for understanding the role of this mammal in the eco-epidemiology of Paracoccidioidomycosis (PCM), one of the most important systemic mycoses in Latin America.
This study aimed to detect P. brasiliensis in different xenarthran species (Dasypus novemcinctus, Cabassous spp., Euphractus sexcinctus, Tamandua tetradactyla and Myrmecophaga tridactyla), by molecular and mycological approaches, in samples obtained by one of the following strategies: i) from road-killed animals (n = 6); ii) from naturally dead animals (n = 8); iii) from animals that died in captivity (n = 9); and iv) from living animals captured from the wild (n = 2). Specific P. brasiliensis DNA was detected in several organs among 7/20 nine-banded armadillos (D. novemcinctus) and in 2/2 anteaters (M. tridactyla). The fungus was also cultured in tissue samples from one of two armadillos captured from the wild.
Members of the Xenarthra Order, especially armadillos, have some characteristics, including a weak cellular immune response and low body temperature, which make them suitable models for studying host-pathogen interaction. P. brasiliensis infection in wild animals, from PCM endemic areas, may be more common than initially postulated and reinforces the use of these animals as sentinels for the pathogen in the environment.
[Show abstract][Hide abstract] ABSTRACT: Lacazia loboi is a geographically restricted, uncultivated fungal pathogen of humans and dolphins. Previous investigations using 18S small unit rDNA, chitin synthase 2 and gp43 DNA sequences positioned L. loboi as a close relative of Paracoccidioides brasiliensis. However, given the few individuals of L. loboi studied and the high degree of genetic variation observed in P. brasiliensis, the existence of L. loboi as an independent species has been questioned. To investigate the phylogenetic position of this species, we conducted a phylogenetic analysis using 20 L. loboi collections (L. loboi was obtained from proven cases of lacaziosis and 14 collections were maintained in mice, the others were analyzed from DNA taken directly from infected human tissue.). L. loboi DNA sequence was compared to that from 17 P. brasiliensis strains that represented the known variation in this species, and outgroup taxa in the Onygenales (Ajellomyces and Coccidioides species). Our analyses used DNA sequence from ITS rRNA, and partial coding sequences of chitin synthase 4, ADP-ribosylation factor, and gp43. Nucleotide variation among strains of L. loboi was minor but numerous nucleotide mismatches and multiple gaps were found for these gene regions among members in the Ajellomycetaceae, including P. brasiliensis. Phylogenies inferred using neighbor-joining, maximum parsimony and Bayesian analyses showed no significant conflict and depicted L. loboi as a well-supported, monophyletic group that was sister to the Paracoccidioides clade. These results argue for maintaining L. loboi as a taxon independent from Paracoccidioides within the Ajellomycetaceae.
Mycological Research 06/2009; 113(Pt 8):851-7. · 2.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Armadillos of the species Dasypus novemcinctus have been used as an experimental model of leprosy. Besides non-human primates, they are the only species naturally infected with Mycobacterium leprae and when experimentally inoculated, reproduce the lepromatous form of the disease producing large quantities of bacilli. This species has been maintained in captivity by numerous researchers and specific housing and feeding requirements have been developed to guarantee their survival during long experimental periods. In the 'Lauro de Souza Lima' Institute, armadillos receive dog food, ground beef, boiled eggs and vitamin C. However, despite the balanced diet, anemia has been observed in some captive animals, especially in armadillos inoculated with M. leprae in advanced stages of infection. Thus, the objective of the present study was to evaluate the effect of iron sulfate supplementation in the feed provided for armadillos, both inoculated and non-inoculated with M. leprae, by means of the evaluation of their hematological profile. Fourteen armadillos received 10 mg/animal of iron sulfate (Hematofer(R)) diluted in sterile water mixed with their daily feed for 50 days. Hemograms and serum iron dosages for each armadillo were performed before and after supplementation. The hematocrit values increased significantly after iron supplementation, both in armadillos inoculated and non-inoculated with M. leprae. It is possible that the amount of iron in the feed is insufficient for the formation of hemoglobin, leading to microcytic anemia. Dietary supplementation with iron sulfate reversed this state, showing the importance of understanding the metabolism of exotic species for their maintenance in captivity, and thus ensuring their well-being.
Brazilian journal of biology = Revista brasleira de biologia 03/2009; 69(1):117-22. · 0.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Jorge Lobo's disease (Lacaziosis) is a subcutaneous infection of humans living in the Amazon region of Latin America, and in dolphins inhabiting the east coastal areas of the United States. The disease mainly affects people from rural areas living or working in close contact with vegetation and aquatic environments. Most patients refer having developed lesions after accidental trauma with plant thorns or insect bites. Inter-human transmission has never been confirmed suggesting that Lacazia loboi is acquired from environmental propagules.
We report the case of a 41-year-old woman from São Paulo, Brazil, a non-endemic area of Jorge Lobo's disease, with L. loboi skin infection most likely accidentally acquired while manipulating experimentally infected mice in the laboratory.
Because many patients with Jorge Lobo's disease do not recall accidental skin trauma before their infections, the possibility of accidentally acquired Jorge Lobo's disease through unnoticed broken skin should be considered during the clinical investigation of nodular skin diseases in people who have contact with the fungus or who live in endemic areas. This is the second report of animal to human transmission of this disease.
[Show abstract][Hide abstract] ABSTRACT: Armadillos are primitive mammals used as food, mostly in rural areas. These animals may be sources of toxoplasmosis and leptospirosis infection for humans, but there is little information about their potential risk as reservoirs. In order to determine the prevalence of armadillos infected by Toxoplasma gondii and Leptospira spp., serum samples of 31 nine-banded armadillos (Dasypus novemcinctus), three six-banded armadillos (Euphractus sexcinctus), two naked-tailed armadillos (Cabassous tatouay) and two long-nosed armadillos (D. hybridus), captured in the mid-west region of the state of São Paulo, were analyzed for leptospirosis using the Microscopic Agglutination Test (MAT-l), and for toxoplasmosis using the Modified Agglutination Test (MAT-t). Only 4/31 (12.90%) nine-banded armadillos were positive for T. gondii, while 3/31 (9.68%) nine-banded armadillos and 1/3 (33.33%) six-banded armadillos presented antibodies to Leptospira spp., demonstrating the potential risk of T. gondii and Leptospira spp. transmission to humans, mainly due the habit of eating the meat of these animals in rural areas.
[Show abstract][Hide abstract] ABSTRACT: Infectious and parasitic diseases have always challenged man. Although many of them are typically seen in some areas of the world and can be adequately managed by just improving socioeconomic status and sanitary conditions, they are still quite prevalent and may sometimes be seen outside their original geographical areas. Human migration due to different reasons, tourism, blood transfusion and solid organ transplantation has created new concerns for health professionals all over the world. If not for diagnostic purposes, at least these tropical and infectious diseases should be largely known because their epidemiology, pathogenesis, host/parasite interaction, inflammatory and reparative responses are quite interesting and teach us about human biology. Curiosity is inherent to pathology practice and so we are compelled to look for things other than tumours or degenerative diseases. This review focuses on infectious and parasitic diseases found in a developing country and brings up-to-date information on diseases caused by viruses (dengue, yellow fever), bacteria (typhoid fever, leprosy), parasites (Chagas' disease, cutaneous and visceral leishmaniasis, amoebiasis, Capillaria hepatica, schistosomiasis, cysticercosis) and caused by fungi (paracoccidioidomycosis, cryptococcosis, histoplasmosis) that may be useful for pathologists when facing somewhat strange cases from developing countries.