Maria Victoria Periago

• B.S. in Biology, M.Sc., PhD
• Chief Scientific Officer/Independet Researcher at Fundación Mundo Sano/CONICET

Background Mother-to-child transmission (MTCT) of Trypanosoma cruzi and hepatitis B virus (HBV) increases morbidity and disability in Latin America and the Caribbean. The tailormade comprehensive antenatal care based on the Framework for the elimination of MTCT of HIV, syphilis, hepatitis B virus (HBV), and Chagas disease (EMTCT Plus) has been impl...

Introducción: Los parásitos intestinales afectan particularmente a grupos poblacionales vulnerables siendo de importancia su abordaje en zonas endémicas. Objetivo: Evaluar la relación de parásitos intestinales con características socioeconómicas y estado nutricional antropométrico. Metodología: Estudio observacional, y transversal en niños de 1 a 1...

Soil-transmitted helminths (STHs) are a group of parasites that are globally distributed and are the most prevalent neglected disease (NTD) in Latin America and the Caribbean (LAC); their presence is associated with health and development problems. In Argentina, their distribution is heterogenous, and there are highly endemic areas in the north of...

Argentina has a heterogeneous prevalence of infections by intestinal parasites (IPs), with the north in the endemic area, especially for soil-transmitted helminths (STHs). We analyzed the spatial patterns of these infections in the city of Tartagal, Salta province, by an observational, correlational, and cross-sectional study in children and adoles...

Prevalencia de enteroparasitosis y riesgo asociado a características socioeconómicas en niños y adolescentes de Tartagal, Salta Scavuzzo CM(1,2,4), Oberto MG(1), Campero MN(1,2,4), Fringes RA(1), Lugea Nin TR(1), Uribe FE(1), Porcasi X(3), Periago MV(3,4). (1)Escuela de Nutrición, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba. (2...

Caracterización de patrones espaciales de parásitos intestinales y estado nutricional en niños y adolescentes de Tartagal, Salta Scavuzzo CM(1,2,4), Oberto MG(1), Campero MN(1,2,4), Maidana RE(1), Bruno PA(1), Prosdocimo J(1), Somerfeld AD(1), Periago MV(3,4), Porcasi X(3). (1)Escuela de Nutrición, Facultad de Ciencias Médicas, Universidad Nacion...

Background Soil-transmitted helminths (STHs) are widely distributed throughout the world. Various factors, including the environment, socioeconomic characteristics, and access to water and sanitation, play an important role in the spread and persistence of these parasites within communities. They, in turn, affect the growth and development of membe...

Hookworm, a parasitic infection, retains a considerable burden of disease, affecting the most underprivileged segments of the general population in endemic countries and remains one of the leading causes of mild to severe anemia in Low and Middle Income Countries (LMICs), particularly in pregnancy and children under 5. Despite repeated large scale...

Strategies for the prevention of arboviral diseases transmitted by Aedes aegypti have traditionally focused on vector control. This remains the same to this day, despite a lack of documented evidence on its efficacy due to a lack of coverage and sustainability. The continuous growth of urban areas and generally unplanned urbanization, which favor t...

Neglected tropical diseases are a group of 20 disabling diseases, which, in particular, are the most common chronic infections in the most vulnerable people. This study aimed to characterize the infection by intestinal parasites (IPs) in dwellings from a peri-urban neighborhood in Pampa del Indio, Chaco (Argentina), and its association with socioec...

Background Chagas Disease (ChD) is a Neglected Tropical Disease (NTD) affecting 6 to 7 million people worldwide, mostly from Latin America. In Argentina, a national control program has been implemented since 1962, yet there are still an estimated 1.6 million infected individuals. Control programs were based almost exclusively on entomological surve...

Introduction Canine soil-transmitted helminth (cSTH) parasites need specific environmental conditions to complete their life cycle. Toxocara canis and T. cati are the most important zoonotic cSTH, since they are the causal agents of human toxocariasis. Canine STHs are dispersed in feces from infected domestic and wildlife canines. In this study, th...

Echinococcosis is a neglected tropical disease (NTD) that affects more than 1 million people, manifested mostly as cystic or alveolar echinococcosis (CE or AE, respectively) [...]

Cystic echinococcosis (CE) is endemic in Argentina, and approximately 30% of the national territory has characteristics appropriate for the development of the zoonotic domestic cycle of this disease. This community-wide study was implemented in rural areas of Añatuya, Santiago del Estero (northern Argentina) to determine the presence of Echinococcu...

BACKGROUND Soil-transmitted helminths (STH) are widely distributed throughout the world. Different factors, including environmental and socioeconomic ones, play an important role in the spread and persistence of these parasites. Studies in northern provinces of Argentina have shown variable prevalence of STH, but the factors associated with their p...

In the field of landscape epidemiology, the contribution of machine learning (ML) to modeling of epidemiological risk scenarios presents itself as a good alternative. This study aims to break with the ”black box” paradigm that underlies the application of automatic learning techniques by using SHAP to determine the contribution of each variable in...

Neglected tropical diseases (NTDs) are a group of 13 disabling diseases, which, in particular, are the most common chronic infections in the most vulnerable people. This study aims to characterize the infection by intestinal parasites in dwellings of Parque Industrial neighborhood, Pampa del Indio, Chaco, and its association with socioeconomic and...

LLa leptospirosis continúa siendo hoy en día un problema para la salud pública, principalmente en poblaciones de bajos recursos socioeconómicos. En este trabajo se presenta la detección de leptospiras patógenas en muestras ambientales (aguas y barros) provenientes de regiones del norte argentino (provincias de Formosa, Salta, Santiago del Estero, M...

Ancylostoma caninum is a zoonotic nematode which is able to affect animals and humans. Diagnosis in the definitive host and environmental detection are key to prevent its dissemination and achieve control. Herein, a new coprological LAMP method for the detection of A. caninum (Copro-LAMPAc) DNA was developed. DNA extraction was performed using a lo...

Background The first case of SARS-CoV-2 was reported in Argentina on 3 March 2020. Measures to limit the spread of the virus were implemented, including complete lockdown (26 March). Nonetheless, the virus spread throughout the country, with a first peak of almost a million cases in October. On 30 November, the government’s recommendation switched...

Background Intestinal parasites (IPs) are widely distributed worldwide and are one of the major contributors to gastrointestinal disease. Their prevalence is associated with poor access to water, sanitation and hygiene (WASH). The objective of this study was to identify the prevalence of IPs, including soil-transmitted helminths (STH), and their re...

Quantitative coprological analyses of children were performed in Alexandria and Behera governorates, Egypt, to ascertain whether individual intensities in the Nile Delta lowlands reach high levels as those known in hyperendemic highland areas of Latin America. Analyses focused on subjects presenting intensities higher than 400 eggs per gram of faec...

Soil-Transmitted Helminths (STH) are highly prevalent Neglected Tropical Disease in Ethiopia, an estimated 26 million are infected. Geographic Information Systems and Remote Sensing (RS) technologies assist data mapping and analysis, and the prediction of the spatial distribution of infection in relation to environmental variables. The influence of...

Toxocariasis is a zoonotic disease caused mainly by Toxocara canis and Toxocara cati and diagnosis in dogs and cats is an important tool for its control. For this reason, a new coprological loop mediated isothermal amplification (LAMP) assay was developed for the simultaneous detection of these species. The primer set was designed on a region of th...

[This corrects the article DOI: 10.1371/journal.pntd.0005574.].

The World Health Organization (WHO) has defined moderate-to-heavy intensity (M&HI) infections with soil-transmitted helminths (Ascaris lumbricoides, Trichuris trichiura and the two hookworms, Ancylostoma duodenale and Necator americanus) based on specific values of eggs per gram of stool, as measured by the Kato-Katz method. There are a variety of...

Background Soil transmitted helminths are highly prevalent worldwide. Globally, approximately 1.5 billion people are infected with Ascaris lumbricoides, Trichuris trichiura or hookworm. Endemic countries carry out periodic mass treatment of at-risk populations with albendazole or mebendazole as a control measure. Most prevalence studies have focuse...

The framework for the elimination of mother-to-child transmission (EMTCT Plus) was proposed by the Pan American Health Organization in 2017 to all member states in order to widen the already existing framework for HIV and syphilis to include elimination of the infection with hepatitis B virus (HBV) and Chagas disease (ChD), now called EMTCT Plus. T...

Background Soil-transmitted helminths (STHs) comprise a group of helminth parasites that are included in the list of Neglected Tropical Diseases and require a passage through the soil to become infective. Several studies have detected that infection with STHs are associated with certain socioeconomic, environmental and soil characteristics. In Arge...

Aunque el lavado de manos evita enfermedades infecciosas graves a bajo costo, sólo una de cada cinco personas se lava las manos después de ir al baño. Este estudio presenta una intervención diseñada interdisciplinariamente, corta y económica para promover el conocimiento sobre el lavado de manos en niños de 10 años y dos estudios piloto para evalua...

Intestinal parasites are a significant cause of morbidity in endemic areas in many low- and middle-income countries (LMICs). Infections with intestinal parasites have been reported in multiple locations throughout Argentina, but infection prevalence is still unknown in many areas. The aim of this study was to determine the prevalence of intestinal...

Background Intestinal parasites (IP) have been reported in point studies from different provinces of Argentina. The presence of soil-transmitted helminths (STH) was detected in many of these studies, including varied prevalences of all five species of STH in the north were the climate is more appropriate for transmission. Nonetheless, Argentina lac...

Aedes aegypti is a vector for Chikungunya, Dengue and Zika viruses in Latin America and is therefore a large public health problem for the region. For this reason, several inter-institutional and multidisciplinary efforts have been made to support vector control actions through the use of geospatial technologies. This study presents the development...

Necator americanus Glutathione-S-Transferase-1 (Na-GST-1) plays a role in the digestion of host hemoglobin by adult N. americanus hookworms. Vaccination of laboratory animals with recombinant Na-GST-1 is associated with significant protection from challenge infection. Recombinant Na-GST-1 was expressed in Pichia pastoris and adsorbed to aluminum hy...

Anti-Na-GST-1 IgE levels in a subset of adults and children (n = 179) living in a hookworm-endemic area of Brazil. IgE levels (kUA/L) were measured by custom ImmunoCAP. (TIF)

CONSORT checklist. (PDF)

Baseline characteristics of study participants in Brazil clinical trial. (PDF)

Baseline characteristics of study participants in US clinical trial. (PDF)

Brazil clinical trial protocol. (PDF)

US clinical trial protocol. (PDF)

A new generation of vaccines for the neglected tropical diseases (NTDs) have now advanced into clinical development, with the Na-GST-1/Alhydrogel Hookworm Vaccine already being tested in Phase 1 studies in healthy adults. The current manuscript focuses on the often overlooked critical aspects of NTD vaccine product development, more specifically, v...

Schematic of the process for the Na-GST-1 catalytic inhibition assay. Outset box shows the chemical reaction of monochlorobimane (MCB) with glutathione resulting in fluorescence. (TIF)

Due to the recent increased use of the McMaster (MM) fecal egg counting method for assessing benzimidazole drug efficacy for treating soil-transmitted helminth (STH) infections, the aim of the current study was to determine the operational value of including the MM method alongside the Kato-Katz (KK) fecal thick smear to increase the diagnostic sen...

Background Robust reference values for fecal egg count reduction (FECR) rates of the most widely used anthelmintic drugs in preventive chemotherapy (PC) programs for controlling soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, and hookworm) are still lacking. However, they are urgently needed to ensure detection of reduc...

In Iran, more than 100 humans and many livestock species have shown to be infected in the northern province of Mazandaran, at the Caspian Sea shore. This picture suggested the need for further multidisciplinary studies to ascertain the extent of the problematics. Three species of lymnaeids were found throughout most of Mazandaran: Lymnaea (Stagnico...

Schistosomiasis is a neglected tropical disease that is responsible for almost 300,000 deaths annually. Mass drug administration (MDA) is used worldwide for the control of schistosomiasis, but chemotherapy fails to prevent reinfection with schistosomes, so MDA alone is not sufficient to eliminate the disease, and a prophylactic vaccine is required....

Human hookworm infection is one among the most prevalent of the neglected tropical diseases. An informative experimental animal model, i.e., one that parallels a human infection, is not available for the study of human hookworm infection. Much of our current understanding of human immune response during hookworm infection relies on studies from exp...

STROBE Checklist. (DOC)

Performance characteristics for ELISAs to detect antibodies in serum and urine to O. viverrini antigen. Panel A shows the mean and 95% CI for 12 Standard Calibration Curves (SCCs) for serum IgG to OV antigen and Panel B shows the estimation of the RDL. Panel C shows the mean and 95% CI for 12 SCC for serum IgG1 to OV-antigen and Panel D shows the e...

Parallelism for Standard Calibration Curves to detect IgG to OV antigen in serum and urine. The linearized 4 parameter logistic log (4-PL) modeling of either a Standard Reference Serum (for IgG, IgG1, and IgG4) or a urine Standard Reference Solution for IgG to OV antigen. Each SRS is serially diluted on an ELISA plate where the Optical Density (OD)...

Serum and urine IgG to OV antigen for the detection of APF versus Endemic Normal individuals. (DOCX)

Improved diagnostic capability using homologous interpolation and Arbitrary Units for the indirect ELISA. (DOCX)

Levels of serum IgG and urine IgG to OV antigen and proteinuria. Panel A shows the linear relationship between Arbitrary Units of serum IgG and urinary IgG to a crude OV antigen extract in the 256 individuals who are OV positive in the study. Panel B shows the levels of proteinuria by clinical groups as determine by point-of care urine dipstick. (P...

Serum antibodies to OV antigen for the detection of cholangiocarcinoma cases compared to endemic normals. (DOCX)

Endemic Burkitt lymphoma (eBL) is linked to Plasmodium falciparum (Pf) infection geographically, but evidence from individual-level studies is limited. We investigated this issue among 354 childhood eBL cases and 384 age-, sex-, and location-matched controls enrolled in Ghana from 1965 to 1994. Immunoglobulin G1 (IgG1) and immunoglobulin G3 (IgG3)...

Approximately 680 million people are at risk of infection with Opisthorchis viverrini (OV) and Clonorchis sinensis, with an estimated 10 million infected with OV in Southeast Asia alone. While opisthorchiasis is associated with hepatobiliary pathologies, such as advanced periductal fibrosis (APF) and cholangiocarcinoma (CCA), animal models of OV in...

Hookworm disease from Necator americanus and Ancylostoma duodenale affects approximately 700 million people, with N. americanus being the predominant species. Unlike other pathogens (e.g., bacterial infections), where "virulence" is described in regards to acute patho-genesis and case-fatality, hookworms are well-evolved, multicellular parasites th...

LBA-3 The incidence of endemic Burkitt lymphoma (eBL) is high in areas where Plasmodium falciparum (Pf) malaria is endemic, which suggests a role of malaria in eBL etiology. Previous data suggest that children with eBL are 5–12 times more likely to have elevated antibody titers to the whole schizont extract, a surrogate of exposure to malaria, comp...

Background Emergence of human fascioliasis prompted a worldwide control initiative including a pilot study in a few countries. Two hyperendemic areas were chosen: Huacullani, Northern Altiplano, Bolivia, representing the Altiplanic transmission pattern with high prevalences and intensities; Cajamarca valley, Peru, representing the valley pattern wi...

Hookworm is considered a neglected tropical disease, which is a group of parasitic and related infectious diseases that are common infections in low-income countries, where they produce a disease burden equivalent to HIV/AIDS or malaria. Despite their importance, progress on developing vaccines for neglected tropical diseases such as hookworm has l...

The need for a vaccineThe Human HookwormVaccine InitiativeThe history of hookwormvaccines: experiments in dogsAntibody production against canine hookwormVaccination against hookwormwith irradiated larvaeLessons from vaccination with irradiated larvaeResearch identifying target proteins for an anti-hookwormvaccineA human hookwormvaccine phase 1 clin...

Hookworms produce a vast repertoire of structurally and functionally diverse molecules that mediate their long-term survival and pathogenesis within a human host. Many of these molecules are secreted by the parasite, after which they interact with critical components of host biology, including processes that are key to host survival. The most impor...

Necator americanus Ancylostoma-secreted protein 2 (Na-ASP-2) is secreted by infective hookworm larvae on entry into human hosts. Vaccination of laboratory animals with recombinant Na-ASP-2 provides significant protection against challenge infections. In endemic areas antibodies to Na-ASP-2 are associated with reduced risk of heavy N americanus infe...

Opisthorchis viverrini is considered among the most important of the food-borne trematodes due to its strong association with advanced periductal fibrosis and bile duct cancer (cholangiocarcinoma). We investigated the relationship between plasma levels of Interleukin (IL)-6 and the risk of developing advanced fibrosis and bile duct cancer from chro...

Objectives: To improve the diagnosis of human fascioliasis caused by Fasciola hepatica and Fasciola gigantica, we evaluated the diagnostic accuracy of an enzyme-linked immunosorbent assay (ELISA), with Fasciola antigen from the adult liver fluke, for the detection of IgG against fascioliasis in human sera. Methods: The sera of 54 fascioliasis ca...

The human hookworms Necator americanus and Ancylostoma duodenale remain among the most common infections of humans in areas of rural poverty in the developing regions of the world, with an estimated 1 billion people infected with one or more of these parasites. Herein, we review the nearly 100 years of research, development, animal testing, and fie...

Unlabelled: Based on the recently established role for the master coregulator MTA1 and MTA1-containing nuclear remodeling complexes in oncogenesis and inflammation, we explored the links between parasitism by the carcinogenic liver fluke Opisthorchis viverrini and this coregulator using both an Mta1(-/-) mouse model of infection and a tissue micro...

Unlabelled: Schistosoma haematobium is responsible for two-thirds of the world's 200 million to 400 million cases of human schistosomiasis. It is a group 1 carcinogen and a leading cause of bladder cancer that occurs after years of chronic inflammation, fibrosis, and hyperproliferation in the host liver. The coevolution of blood flukes of the genu...

A detailed overview of the calculations made to assess the accuracy of estimating drug efficacy (XLS)

Background: The Kato-Katz thick smear (Kato-Katz) is the diagnostic method recommended for monitoring large-scale treatment programs implemented for the control of soil-transmitted helminths (STH) in public health, yet it is difficult to standardize. A promising alternative is the McMaster egg counting method (McMaster), commonly used in veterinar...

CONSORT Checklist (0.22 MB DOC)

Trial Protocol (1.17 MB PDF)

The three major soil-transmitted helminths (STH) Ascaris lumbricoides, Trichuris trichiura and Necator americanus/Ancylostoma duodenale are among the most widespread parasites worldwide. Despite the global expansion of preventive anthelmintic treatment, standard operating procedures to monitor anthelmintic drug efficacy are lacking. The objective o...

Over the next decade, a new generation of vaccines will target the neglected tropical diseases (NTDs). The goal of most NTD vaccines will be to reduce the morbidity and decrease the chronic debilitating nature of these often-forgotten infections – outcomes that are hard to measure in the traditional potency testing paradigm. The absence of measurab...

In this study, we evaluate the MM3-COPRO method for detection of Fasciola coproantigens in human fecal samples, and the usefulness of a new preservative/diluent, CoproGuard, developed for preservation of Fasciola coproantigens. The MM3-COPRO assay was evaluated with 213 samples from healthy patients, 30 Fasciola positive fecal samples (according to...

In trematodiases, shape and size of the fluke eggs shed with faeces are crucial diagnostic features because of their typically reduced intraspecific variability. In fascioliasis, the usual diagnosis during the biliary stage of infection is based on the classification of eggs found in stools, duodenal contents or bile. The aim of the present study i...

During an experimental infection of sheep with Fasciola hepatica or F. gigantica, MM3-SERO and MM3-COPRO ELISA tests were applied to compare the kinetics of antibody production and coproantigen release between the 2nd and 32nd week post-infection (wpi). The Kato-Katz technique was used to measure the kinetics of egg shedding by both Fasciola specie...

The association between fasciolosis-induced anaemia and related factors has been quantified in a rodent model. Haematological parameters were analysed in Wistar rats at 20 and 60 weeks post-infection (p.i.). Pigment stones and bile specimens were collected. Serum IgG1, IgG2a and IgE were determined in rat serum samples. Cytokine levels have been co...

In Egypt, the genotyping study of Giardia intestinalis in human is limited. To determine the prevalence of G. intestinalis, faecal samples were collected from Egypt. Samples were concentrated using density gradient centrifugation. The samples were subjected to PCR and DNA sequence analysis for TPI gene. Prevalence of Giardia infection was 34.6% of...

Fasciola gigantica is the main fasciolid species in Africa; however, F. hepatica and F. gigantica overlap in some countries. Egypt deserves mentioning because of the emerging situation of human fascioliasis in the Nile Delta area. The morphometric characteristics of fasciolid adults infecting the main livestock species present in the Nile Delta hum...

Fascioliasis is an important human and animal disease caused by Fasciola hepatica and Fasciola gigantica. In Iran, the distribution of these two species overlaps in most areas, including the northern human endemic province of Gilan where both fasciolids are simultaneously found in individual cattle and buffaloes. A phenotypic study of fasciolid adu...

The free-living amoebae of the genus Acanthamoeba include non-pathogenic and pathogenic species and has been recently classified into 15 different genotypes, T1-T15. In this study, a survey was conducted in order to determine the presence and pathogenic potential of free-living amoebae of Acanthamoeba genus in freshwater sources associated with hum...