Prevalence of intestinal parasites and molecular characterization of Giardia intestinalis, Blastocystis spp. and Entamoeba histolytica in the village of Fortín Mbororé (Puerto Iguazú, Misiones, Argentina)

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 relation to socioeconomic characteristics, as well as a first approach to molecularly characterize the types of Giardia intestinalis, Blastocystis spp. and Entamoeba histolytica present in an indigenous community from Puerto Iguazú, Misiones,Argentina. Methods: A cross-sectional study was conducted in the rural settlement of Fortin Mbororé between January and March 2018. Socioeconomic variables, household characteristics, and stool and blood samples were collected. Standard coprological techniques were used to analyze stool samples, and a complete hemogram was performed on the blood samples. Giardia intestinalis microscopy-positive samples were genetically typed by the β-giardin (bg) gene. Molecular identification of Blastocystis spp. subtypes and E. histolytica were carried out by amplification and sequencing of a partial fragment of the small subunit ribosomal RNA gene (SSU rDNA). Results: The overall prevalence of IPs was 92.7%, with 72.0% specifically for hookworm. IPs were significantly more prevalent in preschool- and school-age children (P < 0.05). No formal education (P = 0.035), the presence of unimproved floors (P = 0.001) and overcrowding (P = 0.005) were significantly associated with IP infection. Hookworm was associated with anemia (P = 0.019). Molecular characterization revealed the presence of E. histolytica sub-assemblages AII (12.5%), AIII (87.5%) and BIV (100%); one case of sub-assemblage D for G. intestinalis; and the presence of subtypes ST1 (14.8%), ST2 (14.8%) and ST3 (70.4%) of Blastocystis spp. Conclusions: Protozoans detected in this study are transmitted mainly through water contaminated with fecal matter,evidencing the need to improve the quality of water and sanitation for the inhabitants of Fortín Mbororé. Molecular characterization showed that domestic animals can be implicated in the zoonotic transmission of G. intestinalis and Blastocystis spp. to humans. A hyperendemic area for STH was found, with hookworm prevalence greater than 50%. Therefore, improvements in WASH as well as mass deworming programs need to be implemented in this area to control and decrease the prevalence of IPs in general and STH in particular.Fil: Candela, Ernesto. Universidad de Valencia; EspañaFil: Goizueta, Carolina. Fundación Mundo Sano; ArgentinaFil: Periago, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Mundo Sano; ArgentinaFil: Muñoz Antoli, Carla. Universidad de Valencia; Españ

Prevalence of intestinal parasites and related risk factors in rural localities from Pampa del Indio, Chaco, Argentina

Intestinal parasites are a significant cause of morbidity in endemic areas in many low- and middle-income countries (LMIC). 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 parasites in rural areas surrounding Pampa del Indio, Chaco, Argentina, and to identify risk factors for human infections. In the current study, a survey of three rural neighborhoods surrounding the town of Pampa del Indio was conducted in July 2018. A total of 24 households were surveyed. A questionnaire to assess socio-economic and household variables was administered and fecal samples were collected. Of the 62 stool samples analyzed, an intestinal parasite prevalence of 46.8% (29 cases) was found. The most common parasite identified was Endolimax nana (22.6%), followed by Giardia intestinalis (17.7%), and Entamoeba coli (16.1%). Most of the intestinal parasites found were protozoa, but three cases of helminths (4.8%) were also identified. Participants were polyparasitized at a rate of 19.4%. This study did not identify any statistically significant risk factors for infection but revealed a high overall rate of parasitism in the selected communities.Fil: Richards, Lindsay Renee. University of Florida; Estados UnidosFil: Delgado, Cintia. Fundación Mundo Sano; ArgentinaFil: Goy, Marcia. Hospital Dante Tardelli; ArgentinaFil: Liang, Song. Fundación Mundo Sano; ArgentinaFil: Periago, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Mundo Sano; Argentin

Intestinal parasitic infections in a community from Pampa del Indio, Chaco (Argentina) and their association with socioeconomic and environmental factors

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 socioeconomic and environmental variables. Single stool samples were collected from all individuals older than 1 year through household visits and processed using coprological sedimentation and flotation techniques. Standardized questionnaires were used at the household level to collect socio-economic information. Environmental variables were obtained from the Planetscope image, Landsat 8 images and remote sensors, while land-use layers were obtained through the use of a maximum likelihood algorithm. Stool samples were provided by 314 individuals. The prevalence of IPs found was 30.6% (n = 96), with a predominance of Giardia lamblia (12.7%, n = 40) and Hymenolepis nana (7.6%, n = 24). The only soil-transmitted helminth found was Strongyloides stercoralis with a 2.5% prevalence (n = 8). Individuals of adult age (> 18 years) were 0.65 times less likely to present parasitic infections with respect to children and adolescents. The only environmental variable that was closely associated with the presence of IPs, was the Normalized Difference Water Index (NDWI), a measure of humidity; being higher around houses with positive individuals. Most of the IPs found in this study were of water-borne transmission and those transmitted directly from person-to-person, therefore fecal contamination is present. We believe that the low prevalence of STH in this area, which requires a passage through the soil, is related to the environmental characteristics, which are unsuitable for the development/permanence of the infective stages of these parasites. The geospatial data and tools used herein proved to be useful for the study of the relationship between the different factors that influence the presence of IPs in a community, from an eco-health approach.Fil: Scavuzzo, Carlos Matias. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Fundación Mundo Sano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Delgado, Cintia. Fundación Mundo Sano; ArgentinaFil: Goy, Marcia. Hospital Dr. Dante Tardelli; ArgentinaFil: Crudo, Favio. Fundación Mundo Sano; ArgentinaFil: Porcasi, Ximena. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; ArgentinaFil: Periago, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Mundo Sano; Argentin

Interaction between spatial and temporal scales for entomological field data: Analysis of Aedes Aegypti oviposition series

Background In Argentina, Aedes aegypti represents an important public health threat, since it is the vector responsible for the transmission of dengue, chikungunya, zika and yellow fever. Mundo Sano Foundation has been carrying out periodic surveys of immature vector stages in several cities of northern Argentina. The main tool to mitigate their spread is through vector control. The identification of vector "hot spots" is an important key to design preventive program tools. Geostatistical techniques such as spatial autocorrelation (SAC) and kriging interpolation can be used to predict vector abundance in unsampled areas using data obtained from monitored sites. The knowledge of the spatial autocorrelation of vector abundance is fundamental and it can also be used to design disease surveillance strategies: To determine the characteristics of chemical control; to select ovitrap placement (distance between samples); and to determine the optimum sample size, among others. It is important to analyze the effect of the variation of the scale in the observed phenomenon. Methods This paper analyzes a two years series of weekly oviposition data from 25 ovitraps distributed in the urban area of a small city (104 measurements were collected for each ovitrap). We aim to understand how the relationship between sites measurements varies considering its relative location in the city, for different temporal sampling frequency or temporal resolution (TR). Different similarity measures between curves and graphic representations of these relationships, are explored. Among these, an innovative use of polar graphs -a tool commonly used to detect changes in satellite images- is examined. We evaluate variograms and SAC for multitemporal data (oviposition curves) at each TR. Results Similarity between curves does not show spatial continuity in relation to the spatial arrangement of ovitraps, may be due to the effect of processes that are only observable at the microhabitat scale or due to sociodemographic factors. As the temporal resolution is greater in a given area, a greater number of ovitraps are needed to capture the spatial heterogeneity of the abundance of the vector. At the maximum TR analyzed, the minimum distance of spatial correlations was set at 1000 m. This has implications on the quantity of ovitraps per area unit required in the field in order to obtain a good description of the population dynamics of Ae. aegypti at the peridomestic level. Conclusion The results would indicate that when varying the time scale of analysis, the spatial scale should be modified accordingly to adapt to the new data structure. The ability to predict ecological phenomena depends on the relationships between spatial and temporal scales. The approach and innovative statistical tools described in this study, based on empirical data from a field study, may be used by different Ae. aegypti monitoring and control programs in order to design and implement tailor-made interventions. It would allows to support not only the selection of field samples, and to obtain data interpolation parameters, but also to contribute to the development of vector abundance models.Fil: Lanfri, Sofía. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Fundación Mundo Sano; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Espinosa, Manuel. Fundación Mundo Sano; ArgentinaFil: Lanfri, Mario. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Periago, Maria Victoria. Fundación Mundo Sano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Abril, Marcelo. Fundación Mundo Sano; ArgentinaFil: Scavuzzo, Carlos Marcelo. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Universidad Nacional de Córdoba; Argentin

Handwashing promotion in 10-year-old children: intervention studies in Northern Argentina

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 evaluar su impacto. En el piloto 2016 (Puerto Iguazú, Argentina), se compararon las respuestas a una encuesta sobre lavado de niños que participaron y no participaron de la intervención. La intervención consistió en actividades lúdicas sobre el lavado de manos. En el piloto 2017 (cuatro localidades del norte argentino), se compararon las respuestas de niños previas y posteriores a la intervención.Los resultados de ambos estudios piloto indicaron que esta intervención tiene potencial para promover el conocimiento sobre los pasos que deben seguirse para un correcto lavado de manos.Although handwashing prevents serious infectious diseases at low cost, only one in five people wash their hands after using the bathroom. This study presents an interdisciplinary, short-term and low-cost intervention aimed at promoting knowledge about handwashing in 10-year-old children and two pilot studies to assess its impact. In the 2016 pilot study, conducted in Puerto Iguazú city, the responses to a survey about handwashing of children who participated and did not participate in the intervention were compared. The intervention consisted in playful activities in which children were instructed in different aspects of handwashing. In the 2017 pilot, carried out in four locations in northern Argentina, the responses of children before and after the intervention were compared. The results of both pilot studies indicated that this intervention has the potential to promote knowledge about the steps needed to achieve proper hand washing.Fil: Hermida, Maria Julia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Mundo Sano; Argentina. Universidad Nacional de Hurlingham. Instituto de Educacion.; Argentina. Universidad Torcuato Di Tella; ArgentinaFil: Ramírez, Verónica Adriana. Universidad de Buenos Aires. Facultad de Psicología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Goizueta, Carolina. Fundación Mundo Sano; ArgentinaFil: Periago, Maria Victoria. Fundación Mundo Sano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Operational satellite-based temporal modelling of Aedes population in Argentina

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 of an operational system for the application of free access to remotely sensed products capable of assessing the oviposition activity of Ae. aegypti in all of Argentina?s northern region with the specific aim to improve the current Argentine National Dengue risk system. Temporal modelling implemented includes remotely sensed variables like the normalized difference vegetation index, the normalized difference water index, day and night land surface temperature and precipitation data available from NASA?s tropical rainfall measuring mission and global precipitation measurement. As a training data set, four years of weekly mosquito oviposition data from four different cities in Argentina were used. A series of satellite-generated variables was built, downloading and resampling the these products both spatially and temporally. From an initial set of 41 variables chosen based on the correlation between these products and the oviposition series, a subset of 11 variables were preserved to develop temporal forecasting models of oviposition using a lineal multivariate method in the four cities. Subsequently, a general model was generated using data from the cities. Finally, in order to obtain a model that could be broadly used, an extrapolation method using the concept of environmental distance was developed. Although the system was oriented towards the surveillance of dengue fever, the methodology could also be applied to other relevant vector-borne diseases as well as other geographical regions in Latin America.Fil: Espinosa, Manuel. Fundación Mundo Sano; ArgentinaFil: Di Fino, Eliana Marina Alvarez. Fundación Mundo Sano; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Abril, Marcelo. Fundación Mundo Sano; ArgentinaFil: Lanfri, Mario. Centro Espacial Teófilo Tabanera; ArgentinaFil: Periago, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Mundo Sano; ArgentinaFil: Scavuzzo, Carlos Marcelo. Centro Espacial Teófilo Tabanera; Argentin

A Cross-Sectional Study to Detect Cystic Echinococcosis in Añatuya, Santiago Del Estero (Argentina)

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 Echinococcus granulosus sensu lato in the definitive host (dogs) and the presence of CE in humans. Infection data from dogs were obtained through the collection and analysis of fecal samples; these were processed through sedimentation/flotation techniques and PCR. The presence in humans was determined by ultrasound (US) and serology (ELISA confirmed by Western Blot—WB) in the Miel de Palo settlement. A standardized questionnaire was used to investigate potential risk factors for CE; more than half of the studied population carried out activities that favor the maintenance of the cycle. The prevalence of E. granulosus s.l. in dogs from 10 rural settlements, confirmed by PCR, was 4.7% (32/678). The results of the US and serology screening showed a human prevalence of 0.55% (1/183) in Miel de Palo. This prevalence increased to 4.9% (9/183) if imaging-negative but serology-positive (ELISA+WB) individuals are included, as per national guidelines. One of the participants with CE, confirmed by US, was less than 15 years old, which evidences the presence of active transmission. A comprehensive multidisciplinary approach, taking into consideration social, behavioral, sanitary, and environmental aspects intimately tied to the parasite cycle, is needed.Fil: Avila, Héctor Gabriel. Gobierno de la Provincia de San Juan. Ministerio de Salud Publica. Direccion de Epidemiologia. Laboratorio Provincial de Zoonosis.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Cejas, Rosa Graciela. Fundación Mundo Sano; ArgentinaFil: Cabrera, Marta Graciela. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Departamento de Parasitología; ArgentinaFil: Sawicki, Mirna. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Santillan, Graciela Ines. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Departamento de Parasitología; ArgentinaFil: Periago, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Mundo Sano; Argentin

Impact of a public health intervention for active surveillance and mitigation of SARS-CoV-2 in a district from Buenos Aires province, Argentina: a descriptive epidemiological study

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 from social, preventive and compulsory isolation, to social, preventive and compulsory distancing. Objectives To describe a tailored public health strategy to mitigate the spread of SARS-CoV-2 and determine its behaviour in San Antonio de Areco district from Buenos Aires province (Argentina) through a private-public association. Design, setting and participants Surveillance of the virus was performed with the local healthcare system, through early identification of cases and the systematic study of each infected individual and contact, regardless of symptomatology, using telemedicine and a COVID-19-specific outpatient clinic. Real-time PCR was used for detection using both individual and pooled samples, with a 12-hour turnaround time. Results Up to 30 November, a total of 2426 suspected cases were analysed and 578 were confirmed. Surveillance of health personnel and at-risk populations proved effective, mitigating viral spread. Pooling samples allowed reduction of operator time, helped reduce costs, and allowed detection of both symptomatic and asymptomatic cases. Conclusion After 8 months of protocol implementation, the strategy to intensively survey groups at higher epidemiological risk and the systematic search for asymptomatic cases with the incorporation of pooled PCR for diagnosis, in combination with individual testing, is an efficient and viable option in populations with similar characteristics, in the frame of social isolation.Fil: Crudo, Favio. Fundación Mundo Sano; ArgentinaFil: Fernández, Mariana. Fundación Mundo Sano; ArgentinaFil: Rodríguez Fermepín, Marcelo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Entrocassi, Andrea Carolina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Cardone, Karina Angela. No especifíca;Fil: Spina Markmann, Fernando. No especifíca;Fil: Periago, Maria Victoria. Fundación Mundo Sano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chuit, Roberto. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Abril, Marcelo Claudio. Fundación Mundo Sano; Argentin

Development of a low-cost copro-LAMP assay for simultaneous copro-detection of Toxocara canis and Toxocara cati

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 the mitochondrial cox-1 gene. Amplification conditions were evaluated using a temperature gradient (52°C to 68°C), different incubation times (15-120 min), and different concentrations of malachite green dye (0.004-0.4% w/v). The analytical sensitivity was evaluated with serial dilutions of genomic DNA from T. canis and T. cati adult worms, and with serial dilutions of DNA extracted from feces using a low-cost in-house method. The specificity was evaluated using genomic DNA from Canis lupus familiaris, Felis catus, Escherichia coli, Toxascaris leonina, Ancylostoma caninum, Echinococcus granulosus sensu stricto and Taenia hydatigena. The LAMP assay applied to environmental fecal samples from an endemic area showed an analytical sensitivity of 10-100 fg of genomic DNA and 10-5 serial dilutions of DNA extracted from feces using the low-cost in-house method; with a specificity of 100%. Additionally, the total development of the assay was carried out in a basic laboratory and per-reaction reagent cost decreased by ~80%. This new, low-cost tool can help identify the most common agents of toxocariasis in endemic areas in order to manage prevention strategies without having to rely on a laboratory with sophisticated equipment.Fil: Avila, Héctor Gabriel. Universidad Católica de Cuyo. Facultad de Ciencias Químicas y Tecnológicas. Laboratorio Provincial de Zoonosis Provincial; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Risso, Marikena Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Ruybal, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Repetto, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Butti, Marcos Javier. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias; ArgentinaFil: Trangoni, Marcos David. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Grune Loffler, Sylvia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología Veterinaria - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Patobiología Veterinaria; ArgentinaFil: Perez, Veronica Mirtha. Gobierno de la Provincia de San Juan. Ministerio de Salud Publica. Direccion de Epidemiologia. Seccion Rabia y Zoonosis.; ArgentinaFil: Periago, Maria Victoria. Fundación Mundo Sano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Safety and immunogenicity of the Na-GST-1 hookworm vaccine in Brazilian and American adults

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 hydroxide adjuvant (Alhydrogel) according to current Good Manufacturing Practice. Two Phase 1 trials were conducted in 142 healthy adult volunteers in the United States and Brazil, first in hookworm-naïve individuals and then in residents of a N. americanus endemic area in Brazil. Volunteers received one of three doses of recombinant Na-GST-1 (10, 30, or 100 μg) adjuvanted with Alhydrogel, adjuvanted with Alhydrogel and co-administered with an aqueous formulation of Glucopyranosyl Lipid A (GLA-AF), or the hepatitis B vaccine. Vaccinations were administered via intramuscular injection on days 0, 56, and 112. Na-GST-1/Alhydrogel was well tolerated in both hookworm-naïve and hookworm-exposed adults, with the most common adverse events being mild to moderate injection site pain and tenderness, and mild headache and nausea; no vaccine-related severe or serious adverse events were observed. Antigen-specific IgG antibodies were induced in a dose-dependent fashion, with increasing levels observed after each vaccination in both trials. The addition of GLA-AF to Na-GST-1/Alhydrogel did not result in significant increases in specific IgG responses. In both the US and Brazil studies, the predominant IgG subclass induced against Na-GST-1 was IgG1, with lesser amounts of IgG3. Vaccination of both hookworm-naïve and hookworm-exposed adults with recombinant Na-GST-1 was safe, well tolerated, and resulted in significant antigen-specific IgG responses. Based on these results, this vaccine will be advanced into clinical trials in children and eventual efficacy studies.Fil: Diemert, David J.. The George Washington University; Estados UnidosFil: Freire, Janaína. Fundación Oswaldo Cruz; BrasilFil: Vanderson, Valente. Fundación Oswaldo Cruz; BrasilFil: Talles, Federico. Fundación Oswaldo Cruz; BrasilFil: Grahek, Shannon. The George Washington University; Estados UnidosFil: Campbell, Doreen. The George Washington University; Estados UnidosFil: Jariwala, Amar. The George Washington University; Estados UnidosFil: Periago, Maria Victoria. Fundación Oswaldo Cruz; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Enk, Martin. Fundación Oswaldo Cruz; BrasilFil: Gazzinelli, María Flavia. Universidade Federal do Minas Gerais; BrasilFil: Bottazzi, María Elena. Baylor College of Medicine; Estados UnidosFil: Hamilton, Roberto. University Johns Hopkins; Estados UnidosFil: Brelsford, Jill. The George Washington University; Estados UnidosFil: Yakovleva, Anna. The George Washington University; Estados UnidosFil: Guangzhao, Li. The George Washington University; Estados UnidosFil: Peng, Jin. The George Washington University; Estados UnidosFil: Correa Oliveira, Rodrigo. Fundación Oswaldo Cruz; BrasilFil: Hotez, Peter. Baylor College of Medicine; Estados UnidosFil: Bethony, Jeffrey. The George Washington University; Estados Unido