Prevalencia de parásitos intestinales en muestras de pacientes atendidos en el Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Argentina, 2018-2019 / Prevalence of intestinal parasites in samples of patients attending the Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Argentina, 2018-2019 / Prevalência de parasitas intestinais em amostras de pacientes atendidos no Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Argentina, 2018-2019

Resumen Se evaluaron retrospectivamente los resultados obtenidos de estudios parasitológicos en muestras de heces y escobillados anales remitidos al Laboratorio de Parasitología y Gastroenterología del Hospital de Pediatría "Prof. Dr. Juan P. Garrahan" de la Ciudad de Buenos Aires, Argentina. El objetivo del trabajo fue conocer la prevalencia de los parásitos intestinales observados en las muestras remitidas a este hospital y su distribución en rangos etarios. En el período comprendido entre mayo de 2018 y abril de 2019 se analizó un total de 4713 muestras pertenecientes a 3311 pacientes, que arrojó un resultado total de 29% de positivos (1371/4713). De los exámenes coproparasitológicos el 30% fueron positivos (1193/4025) y se hallaron huevos de Enterobius vermicularis en el 26% (178/688) de los escobillados anales. En las muestras seriadas de heces se obtuvo un 37% de positividad mientras que en muestras únicas un 21%. En la totalidad de muestras fecales, los enteroparásitos más prevalentes fueron Blastocystis spp. en un 14% (579/4025), Giardia duodenalis 11% (456/4025) y Dientamoeba fragilis 7% (291/4025). Los resultados demostraron diferencias significativas con mayor prevalencia de parásitos intestinales en pacientes en edad escolar comprendidos entre los 6 y 10 años, en relación a los de edad preescolar. En las muestras fecales analizadas se evidenció un predominio de parasitismo de protozoos sobre helmintos, por lo que se debería considerar reforzar el diagnóstico de laboratorio de esas especies mediante técnicas, como coloraciones, que posibiliten su hallazgo y confirmación.

Abstract The results obtained of the coproparasitological studies and anal swab submitted to the laboratory of the Parasitology Section of the Hospital de Pediatría "Prof. Dr. Juan P. Garrahan" of the Buenos Aires City, Argentina, were retrospectively evaluated The aim of this study was to determine the prevalence of intestinal parasites found on the submitted samples and to evaluate their frequency according to the age of the patients. Within the period between May 2018 and April 2019, a total of 4713 samples corresponding to 3311 patients were analyzed and intestinal parasites were present in 29% (1371/4713). In 30% of coproparasitological studies parasite estructures were found (1193/4025) and 26% of anal swab samples were positive for the presence of Enterobius vermicularis eggs (178/688). In serial fecal samples, 37% positive results were obtained, while in single samples, 21%. The most prevalent enteroparasites calculated from the total fecal samples were: Blastocystis spp. with 14% (579/4025), followed by Giardia duodenalis 11% (456/4025) and Dientamoeba fragilis 7% (291/4025). The incidence of intestinal parasites was higher in the group of patients between 6 and 10 years, and the existence of significant differences between proportions of parasitized patients in preschool and school infants, was observed. In the faecal samples analyzed, a greater prevalence of parasitism caused by protozoa than by helminths was evidenced, for which reason it should be considered, reinforcing the laboratory diagnosis using techniques such as stains that allow its finding and confirmation.

Resumo Os resultados obtidos de estudos parasitológicos em amostras fecais e esfregaços anais enviados ao Laboratório de Parasitologia e Gastroenterologia do Hospital de Pediatría "Prof. Dr. Juan P. Garrahan" da Cidade de Buenos Aires, Argentina, foram avaliados retrospectivamente. O objetivo do estudo foi avaliar a prevalência dos parasitas intestinais observados nas amostras enviadas a este hospital e sua distribuição por faixas etárias. Durante o período compreendido entre maio de 2018 a abril de 2019 foram analisadas 4713 amostras, correspondentes a 3311 pacientes, o que deu um resultado total de 29% de positivos (1371/4713). 30% dos exames coproparasitológicos foram positivos (1193/4025) e foram encontrados ovos de Enterobius vermicularis em 26% (178/688) dos esfregaços anais. Nas amostras seriadas fecais foram obtidos 37% de resultados positivos, enquanto que em amostras únicas, 21%. Os enteroparasitas mais prevalentes na totalidade das amostras fecais foram Blastocystis spp. em 14% (579/4025), Giardia duodenalis 11% (456/4025) e Dientamoeba fragilis 7% (291/4025). Os resultados demonstraram diferenças significativas com maior prevalência de parasitas intestinais em pacientes em idade escolar da faixa etária entre 6 e 10 anos, em relação aos da pré-escola. Nas amostras fecais analisadas, evidenciou-se um predomínio de parasitismo por protozoários por sobre helmintos, pelo qual deve ser considerado o reforço do diagnóstico laboratorial dessas espécies por meio de técnicas, como colorações que permitam a sua localização e confirmação.

Concordance between the zinc sulphate flotation and centrifugal sedimentation methods for the diagnosis of intestinal parasites / Concordancia entre los métodos de flotación con sulfato de zinc y sedimentación centrífuga para el diagnóstico de parásitos intestinales

Resumen Introduction: The diagnosis of intestinal parasitic infections depends on the parasite load, the specific gravity density of the parasite eggs, oocysts or cysts, and the density and viscosity of flotation or sedimentation medium where faeces are processed. Objective: To evaluate the concordance between zinc sulphate flotation and centrifugal sedimentation in the recovery of parasites in faecal samples of children. Materials and methods: Faecal samples of 330 children from day care centers were evaluated by zinc sulphate flotation and centrifugal sedimentation techniques. The frequencies of detection of parasites by each method were determined and the agreement between the diagnostic techniques was evaluated using the kappa index, with 95% confidence intervals. Results: The faecal flotation in zinc sulphate diagnosed significantly more cases of Trichuris trichiura infection when compared to centrifugal sedimentation (39/330; 11.8% vs. 13/330; 3.9%, p<0.001), with low diagnostic concordance between methods (kappa=0.264; 95% CI: 0.102-0.427). Moreover, all positive samples for Enterobius vermicularis eggs (n=5) and Strongyloides stercoralis larvae (n=3) were diagnosed only by zinc sulphate. No statistical differences were observed between methods for protozoa identification. Conclusions: The results showed that centrifugal flotation in zinc sulphate solution was significantly more likely to detect light helminths eggs such as those of T. trichiura and E. vermicularis in faeces than the centrifugal sedimentation process.

Abstract Introducción. El diagnóstico de infecciones parasitarias intestinales depende de la carga de parásitos, la densidad de la gravedad específica de los huevos, ooquistes o quistes de parásitos, y de la densidad y viscosidad de los reactivos de flotación o sedimentación usados para procesar las heces. Objetivo. Evaluar la concordancia entre el método de flotación de sulfato de zinc y la sedimentación por centrifugación en la recuperación de parásitos en muestras fecales de niños. Materiales y métodos. Se evaluaron las muestras fecales de 330 niños de guarderías mediante las técnicas de flotación con sulfato de zinc y de sedimentación por centrifugación. Se determinó la frecuencia de detección de parásitos con cada método y se evaluó la concordancia entre las técnicas de diagnóstico mediante el índice kappa, con intervalos de confianza del 95 %. Resultados. Mediante la flotación fecal con sulfato de zinc, se diagnosticó un número significativamente mayor de casos de infección por Trichuris trichiura que con la sedimentación por centrifugación (39/330; 11,8 % Vs. 13/330; 3,9 %) (p<0,001), con poco acuerdo entre los métodos (kappa=0,264; IC95% 0,102-0,427). Además, todas las muestras positivas para huevos de Enterobius vermicularis (n=5) y larvas de Strongyloides stercoralis (n=3) se diagnosticaron solamente por sulfato de zinc. No se observaron diferencias estadísticamente significativas entre los métodos para la identificación de protozoos. Conclusiones. La flotación centrífuga en una solución de sulfato de zinc presentó una probabilidad significativamente mayor de detectar los huevos livianos de helmintos como T. trichiura y E. vermicularis en heces, que el proceso de sedimentación por centrifugación.

Prevalencia e intensidad de la infección por geohelmintos y prevalencia de la malaria en escolares de El Salvador / Prevalence and intensity of infection by soil-transmitted helminths and prevalence of malaria among schoolchildren in El Salvador

Introducción. El Salvador no cuenta con datos actualizados de prevalencia en menores de 15 años de la infección por helmintos transmitidos por contacto con el suelo. Además, al ser uno de los países en las Américas que reporta un número bajo de casos de malaria, se considera que su eliminación allí es factible. Objetivo. Determinar la prevalencia y la intensidad de la infección por geohelmintos y la prevalencia de Plasmodium spp. en escolares de 8 a 10 años de El Salvador. Materiales y métodos. Se hizo un estudio de corte transversal en las cinco zonas eco-epidemiológicas del país (planicie costera, depresión central, cadena volcánica, cadena costera y zona montañosa). La presencia de geohelmintiasis se estudió en 1.325 estudiantes y, la de malaria, en 152. Se utilizó la técnica de Kato-Katz para la detección de geohelmintos, y para el diagnóstico de la malaria, una prueba rápida, el estudio mediante microscopía y la prueba de reacción en cadena de la polimerasa. Resultados. La prevalencia total de geohelmintiasis fue de 7,9 % (IC 95% 6,6-9,5). En la planicie costera fue de 14,9 % (IC 95% 10,9-19,7); en la depresión central, de 9,4 % (IC 95% 6,5-13,3); en la cadena volcánica, de 6,6 % (IC 95% 4,2-10,5); en la cadena costera, de 5,9 % (IC 95% 3,8-9,4), y en la cadena montañosa, de 2,6 % (IC 95% 1,4-5,7). La proporción de infección de gran intensidad debida a cualquiera de las especies de geohelmintos fue de 0,3 %. No se encontraron escolares infectados con Plasmodium spp. Conclusión. La prevalencia de geohelmintos fue baja y la especie más prevalente fue Trichuris trichiura . La intensidad de la infección debida a cualquiera de las especies de geohelmintos fue leve (<1 %). Los factores de riesgo asociados a la infección por geohelmintos fueron la defecación al aire libre, no usar calzado y vivir en la planicie costera.

Introduction: El Salvador does not have recent data on the prevalence of infection with soil-transmitted helminths among children aged under 15 years of age. As one of the countries in the Americas that reports few malaria cases, eradication of this disease from El Salvador is considered to be feasible. Objective: To determine the prevalence and intensity of infection by soil-transmitted helminths, as well as the prevalence of Plasmodium spp. in schoolchildren aged 8-10. Materials and methods: A cross-sectional study was carried out in each of the five eco-epidemiological zones of the country (coastal plain, central basin, volcanic range, coastal range and mountain zone). In all 1,325 students we studied the presence of geohelminthiasis, with 152 of them also being tested for malaria. The Kato-Katz technique was used to detect geohelminths while diagnosis of malaria was performed using the rapid diagnostic test, microscopy and polymerase chain reaction. Results: The overall prevalence of geohelminthiasis was 7.9% (95%CI 6.6-9.5%). Values for the five eco-epidemiological zones were as follows: coastal plain, 14.9% (95%CI 10.9-19.7%); central plateau, 9.4% (95%CI 6.5-13.3%); volcanic range, 6.6% (95%CI 4.2-10.5%); coastal range, 5.9% (95%CI 3.8-9.4%), and mountain zone, 2.6% (95%CI 1.4-5.7%). The overall rate of high intensity infection with any of the geohelminth species was 0.3%. No schoolchildren were found infected with Plasmodium spp. by any of the three diagnostic techniques used. Conclusion: Prevalence of geohelminths was low and Trichuris trichiura was the predominant species. Intensity of infection with any of the species of geohelminths was light (<1%). The risk factors associated with infection by soil-transmitted helminths were defecation in the open air, being barefoot and living in coastal areas.

OCCURRENCE OF Blastocystis spp. IN UBERABA, MINAS GERAIS, BRAZIL / Ocorrência de Blastocystis spp. em Uberaba, Minas Gerais, Brasil

Intestinal parasites are a problem for public health all over the world. The infection with Blastocystis, a protozoan of controversial pathogenicity, is one of the most common among them all. In this study, the occurrence of intestinal parasites, with emphasis on Blastocystis, in patients at the Universidade Federal do Triângulo Mineiro was investigated in Uberaba (MG) through microscopy of direct smears and fecal concentrates using Ritchie’s method. Feces of 1,323 patients were examined from April 2011 to May 2012. In 28.7% of them at least one intestinal parasite was identified, and the most frequent organisms were Blastocystis spp. (17.8%) and Giardia intestinalis (7.4%). The occurrence of parasitism was higher in children aged 6 -10 years old, and the infection with Blastocystis spp. was higher above the age of six (p < 0.001). The exclusive presence of G. intestinalis and of Blastocystis spp. was observed in 5.4% and 12.2% of the patients, respectively. Regarding patients with diarrheic feces, 8% revealed unique parasitism of Blastocystis spp. Other intestinal parasites observed in children were Ascaris lumbricoides (0.3%) and Entamoeba histolytica/dispar/moshkovskii (1.4%). The Ritchie’s method was more sensitive (92.8%) when compared to direct microscopy (89.8%), with high agreement between them (97.7%, kappa = 0.92). In conclusion, the occurrence of Blastocystis spp. in Uberaba is high and the presence of diarrheic feces with exclusive presence of the parasite of Blastocystis spp. was observed.

Parasitos intestinais são um problema de saúde pública no mundo e a infecção por Blastocystis, protozoário de patogenicidade controversa, é uma das mais frequentes. Nesse estudo foi investigada a ocorrência de parasitos intestinais em pacientes atendidos na Universidade Federal do Triângulo Mineiro, em Uberaba (MG), com ênfase em Blastocystis, pelos métodos parasitológicos direto e de Ritchie. Foram examinadas fezes de 1.323 pacientes de abril/2011 a maio/2012. Em 28,7% deles foi identificado um parasito intestinal, sendo Blastocystis spp. (17,8%) e Giardia intestinalis (7,4%) os mais frequentes. A ocorrência de parasitismo foi maior em crianças de 6-10 anos e a infecção por Blastocystis spp. foi maior acima de seis anos (p < 0,001). Presença exclusiva de G. intestinalis e de Blastocystis spp. foi observada em 5,4% e 12,2% dos pacientes, respectivamente, sendo que dos pacientes com fezes diarreicas, 8% apresentavam parasitismo exclusivo por Blastocystis spp. Outros parasitos intestinais observados em crianças foram Ascaris lumbricoides (0,3%) e Entamoeba histolytica/dispar/moshkovskii (1,4%). O método de Ritchie foi mais sensível (92,8%) que o direto (89,8%), com alta concordância entre eles (97,7%, kappa = 0,92). Em conclusão, a ocorrência de Blastocystis spp. em Uberaba é elevada e foi observada a presença de fezes diarreicas com parasitismo exclusivo por Blastocystis spp.

Método FAMACHA para detectar anemia clínica causada por Haemonchus contortus em cordeiros lactentes e ovelhas em lactação / FAMACHA method for detecting clinical anemia caused by Haemonchus contortus in suckling lambs and lactating ewes

O controle das endoparasitoses gastrintestinais em pequenos ruminantes tem sido tradicionalmente realizado por meio do uso indiscriminado dos anti-helmínticos, porém essa prática tem resultado em grande pressão de seleção de parasitas resistentes. Métodos seletivos (ex: FAMACHA/FMC e contagem de ovos nas fezes/OPG) e que apresentem boa sensibilidade para identificar os animais que necessitam receber o tratamento químico são importantes alternativas aos métodos tradicionais. O objetivo desse trabalho foi determinar a sensibilidade e a especificidade do método FMC, usado para detectar anemia causada por Haemonchus contortus em ovinos da raça Suffolk, em duas categorias de alta suscetibilidade; cordeiros lactentes e ovelhas durante a fase de lactação...

The control of gastrointestinal parasites in small ruminants has traditionally involved the indiscriminate use of anthelmintic drugs that resulted in a high parasite selection pressure for anthelmintic resistance. Selective methods (ex.: FAMACHA/FMC and faecal egg count/EPG), which have good sensitivity to identify animals that need drug treatment, are important alternative methods for parasite control. The objective of this study was to determine the sensitivity and specificity of the FMC method to detect clinical anemia caused by Haemonchus contortus in two highly susceptible categories of Suffolk sheep; suckling lambs and lactating ewes...

Enteroparasitismo en Indígenas Terena en el Estado de Mato Grosso do Sul, Brasil / Intestinal Parasitism in Terena Indigenous People of the Province of MatoGrossodoSul, Brazil

Objetivo Considerando que más de la mitad de la población mundial está infectada por protozoarios y helmintos intestinales, con alta prevalencia en las zonas más pobres, esta investigación tuvo como objetivo identificar la prevalencia de los parasitismos entre indígenas de la etnia Terena, establecidos en el Estado de Mato Grosso do Sul. Metodología Se examinaron 134 muestras de heces de individuos de la comunidad indígena. Estas se conservaron en solución de Merthiolate-iodo-formol (MIF). Los exámenes de laboratorio fueron realizados por las técnicas de Hoffman, Pons y Janer; Willis y Kinyoun. Resultados Se identificaron infecciones por helmintos nematodos de las especies Ascaris lumbricoides, Ancylostomidae, Enterobius vermicularis, Strongyloides stercoralis, y Trichuris trichiura; cestodos de la especie Hymenolepis nana, y Taeniaspp. También por protozoarios de las especies Cryptosporidium spp., Giardia lamblia, Endolimax nana, Entamoeba coli, y Entamoeba histolytica. De las muestras investigadas, 23,1% fueron negativas; de los 76,9 % parasitados hubo diferencia estadísticamente no significativa para el parasitismo en hombres y mujeres examinados, de unoa 33 años de edad, y sobre parasitismo mono específico, o con simultaneidad de especies. Como diversidad parasitaria fueron encontradas siete especies de helmintos nematodos y cestodos, y cinco de protozoarios Archamoebae, flagelados y enterozoários. Conclusiones Los resultados fueron la base para la orientación e intervención adecuada, revelando la necesidad de la implantación de medidas gubernamentales y socioeducativas para mejorar las condiciones de vida de esta comunidad...

Objective Considering that intestinal protozoans and helminths infect more than half of the world population, with high prevalence in the poorest regions, the objective of this study was to conduct parasitological research among indigenous Terena people established in the state of MatoGrosso do Sul. An inquiry was performed to find the incidence of parasitism in these communities. Methodology 134 aliquots of feces from individuals of the indigenous community were examined. Samples were conserved in Merthiolate-iodine-formol solution (MIF). The laboratory exams were carried out using the techniques of Hoffman, Pons and Janer; Willis and Kinyoun. Results We identified infections of nematode helminths of the species Ascarislumbricoides, Ancylostomidae, Enterobiusvermicularis, Strongyloidesstercoralis, and Trichuristrichiura; and cestodes of the species Hymenolepis nana and Taenia spp. Also found were the protozoan species: Cryptosporidium spp., Giardia lamblia, Endolimax nana, Entamoeba coli, and Entamoebahistolytica. 23.1 % of the samples studied were negative. Of the 76.9 % of samples with parasites, there were non-statistically significant differences in parasitism between men and women examined between 1 and 33 years-of-age. There were also no significant differences between monospecific parasitism and with concurrent species. In terms of parasitic diversity, seven species of nematode and cestodeshelminths were found along with five species of Archamoebae protozoa: flagellates and enterozoans. Conclusions These results were the basis for orientation and appropriate drug intervention and reveal the need for the implementation governmental, social and educational measures to improve the living conditions of that community...

Parasitosis intestinales en Argentina: principales agentes causales encontrados en la población y en el ambiente / Intestinal parasitoses in Argentina: Major causal agents found in the population and in the environment

Las parasitosis intestinales se encuentran ampliamente distribuidas en el mundo, con mayor prevalencia en los países en desarrollo. Principalmente afectan a los niños, en los que además provocan disminución del desarrollo físico y mental, situación que puede potenciarse enormemente cuando se suma a un estado nutricional deficiente. La Organización Mundial de la Salud las considera una de las principales causas de morbilidad, estrechamente ligada a la pobreza y relacionada con inadecuada higiene personal, incorrecta manipulación de los alimentos crudos, falta de servicios sanitarios, falta de provisión de agua potable y contaminación fecal del ambiente. Algunas enfermedades parasitarias se vinculan con condiciones de transmisión que existen universalmente, por lo que son cosmopolitas, mientras que otras tienen distribución geográfica variable. En los últimos años, debido a la globalización, el movimiento de personas de zonas endémicas a regiones no endémicas ha permitido la diseminación de ciertas parasitosis. Y aunque también influyen en la frecuencia de algunas de estas enfermedades las costumbres de los pueblos, las condiciones ambientales son un factor determinante para la supervivencia de los parásitos. En nuestro país, debido a la diversidad de suelos y condiciones climáticas que existen, es posible hallar variedad de agentes causales de estas parasitosis. El objetivo de este trabajo fue realizar una revisión bibliográfica de los agentes parasitarios causantes de enfermedades entéricas encontrados en la República Argentina, tanto en materia fecal de personas como en el ambiente, ya que la contaminación parasitaria de este último constituye un indicador directo del riesgo de infección por parásitos intestinales.

Intestinal parasitic diseases are widely spread in the world, with the highest prevalence in developing countries. Children are mainly affected, showing a decrease in physical and mental development, as well as the expected manifestations of the disease. This situation can be greatly enhanced in children with poor nutritional status. The World Health Organization considers intestinal parasitic diseases a major cause of morbidity, closely linked to poverty and poor personal hygiene, inappropriate handling of raw food, lack of sanitation, lack of potable water supply, and environmental fecal contamination. Some parasitic diseases are cosmopolitan while others have variable geographic distribution, due to different factors such as the presence of exclusive intermediate hosts. In the past few years, globalization allowed the spread of certain parasites from endemic to non-endemic regions. Even though people's customs influence on the frequency of certain parasites, environmental conditions are a determinant factor for parasite survival. In our country, due to the variety of soils and climatic conditions, several causative agents of these parasitoses can be found. The aim of this work was to review the literature on the intestinal parasitic agents found in Argentina in human fecal samples and its environment, as parasitic contamination constitutes a direct indicator of the infection risk by intestinal parasites.

Protozoarios y helmintos intestinales en adultos asintomáticos del estado Zulia, Venezuela / Intestinal protozoa and helminths in asymptomatic adults in the Zulia state, Venezuela

Los estudios de prevalencia de enteroparásitos generalmente se efectúan en población infantil, por ser la más susceptible a estas infecciones; sin embargo, para evaluar la situación en adultos se realizó la presente investigación. Se efectuó el examen coproparasitológico a 95 personas asintomáticas mayores de 18 años, provenientes de 3 diferentes localidades del estado Zulia, Venezuela. Las muestras fecales se sometieron al examen microscópico con SSF-Lugol y método de concentración con formol-éter. 64 individuos (67,36%) presentaron una o varias especies de parásitos intestinales y de éstos, el 81,25% presentaba al menos un parásito patógeno para los humanos. 31 individuos presentaron más de una especie parasitaria (poliparasitismo), con un máximo de 3 especies por hospedador. Se identificaron 7 especies de protozoarios intestinales incluyendo patógenos y comensales, así como 2 especies de helmintos. Predominaron los casos de protozoosis (93) sobre las helmintiasis (10). La mayor frecuencia correspondió a Blastocystis sp. entre los protozoarios y Ascaris lumbricoides entre los helmintos, así mismo, existió un predominio de A. lumbricoides y Trichuris trichiura en la comunidad Los Pescadores, al comparar las tres comunidades estudiadas. La asociación parasitaria más frecuente fue Blastocystis sp. con varias amibas. Este estudio detectó una elevada prevalencia de protozoarios intestinales y particularmente de Blastocystis sp.

Prevalence studies for intestinal parasites are usually performed on children, since they are the most susceptible to these infections; however, this research was conducted to assess the situation in adults. Stool examination was performed on 95 asymptomatic persons over 18 years old, from three different locations in the state of Zulia, Venezuela. Fecal samples were submitted to microscopic examination with SSF-Lugol and the concentration method with formalin ether. Sixty-four individuals (67.36%) had one or more species of intestinal parasites and of these, 81.25% had at least one parasite pathogenic for humans. Thirty-one individuals had more than one parasite species (polyparasitism), with a maximum of three species per host. Seven intestinal protozoa species were identified, including pathogens and commensals, as well as 2 species of helminths. Protozoosis cases predominated (93) over helminths (10). The greatest frequencies corresponded to Blastocystis sp. among protozoa and Ascaris lumbricoides among helminths; also, there was a predominance of A. lumbricoides and Trichuris trichiura in the community Los Pescadores, when comparing the three communities studied. The most frequent parasitic association was Blastocystis sp. with several amoebas. This study found a high prevalence of intestinal protozoa and particularly Blastocystis sp.

Parasitological stool sample exam by spontaneous sedimentation method using conical tubes: effectiveness, practice, and biosafety / Exame parasitológico de fezes pelo método de sedimentação espontânea utilizando tubos cônicos: eficácia, praticidade e biossegurança

INTRODUCTION: Spontaneous sedimentation is an important procedure for stool examination. A modification of this technique using conical tubes was performed and evaluated. METHODS: Fifty fecal samples were processed in sedimentation glass and in polypropylene conical tubes. Another 50 samples were used for quantitative evaluation of protozoan cysts. RESULTS: Although no significant differences occurred in the frequency of protozoa and helminths detected, significant differences in protozoan cyst counts did occur. CONCLUSIONS: The use of tube predicts a shorter path in the sedimentation of the sample, increases concentration of parasites for microscopy analysis, minimizes the risks of contamination, reduces the odor, and optimizes the workspace.

INTRODUÇÃO: A sedimentação espontânea é um procedimento importante para o exame parasitológico de fezes. Uma modificação desta técnica utilizando tubos cônicos foi realizada e avaliada. MÉTODOS: Cinquenta amostras de fezes foram processadas em cálices de sedimentação de vidro e em tubos cônicos de polipropileno. Outras 50 amostras foram usadas para avaliação quantitativa de cistos de protozoários. RESULTADOS: Embora não tenham sido encontradas diferenças significativas na frequência de helmintos e protozoários identificados, houve diferença significativa na contagem de cistos de protozoários. CONCLUSÕES: O uso do tubo prevê um caminho mais curto na sedimentação da amostra, aumenta a concentração de parasitas para a análise microscópica, minimiza os riscos de contaminação, reduz o odor e otimiza o espaço de trabalho.

La prevalencia de geohelmintiasis se relaciona con las condiciones socioambientales / The prevalence of geohelminthiasis is related to socio-environmental conditions

Se realizó un estudio socioambiental y parasitológico en niños de áreas urbanas, periurbanas y rurales de las provincias de Buenos Aires y Misiones. Se completó una encuesta epidemiológica y se tomaron muestras fecales seriadas, las cuales se analizaron mediante técnicas de flotación y sedimentación. Del total de muestras fecales (1893), 5.5% fueron positivas en Buenos Aires y 25.6% en Misiones. El área periurbana de Misiones presentó la mayor prevalencia de parasitosis total (34.1%) y de biparasitados y poliparasitados (45.4%). Las especies más prevalentes fueron Strongyloides stercoralis (22.1%) en el sector periurbano y Ancylostomideos (21.6%) en el área rural de Misiones. Hymenolepis nana y Ascarislumbricoides mantuvieron bajas frecuencias en ambas provincias y Trichuris trichiura sólo se encontró en el periurbano de Buenos Aires. La prevalencia de geohelmintos aumentó con la edad (p < 0.05) y se asoció en el área periurbana de ambas provincias y rural de Misiones con las condiciones socioambientales: vivienda precaria, piso de tierra, eliminación de excretas en letrinas o a cielo abierto, sin recolección domiciliaria de residuos, madre sin actividad laboral, padres sin instrucción primaria (p < 0.05). Las características biogeográficas y las condiciones socioambientales de la provincia de Misiones favorecen la persistencia de las formas parasitarias en el ambiente.

Human intestinal capillariasis: A rare case report from non-endemic area (Andhra Pradesh, India).

Human intestinal capillariasis is caused by Capillaria philippinensis. This disease is endemic in Philippines and Thailand. To the best of our knowledge, we report the third case of human intestinal capillariasis from India and the first case from Andhra Pradesh, which is a non-endemic area. A 40-year-old female presented with diarrhoea, vomiting, decreased urinary output, ascitis, pedal oedema, hypoalbuminemia, and electrolyte imbalance. Microscopic examination of stool sample revealed the presence of ova, larvae, and adult worms of C. philippinensis. Patient recovered from the disease after taking albendazole 400 mg daily for 1 month along with supportive treatment.

A comparative study of the TF-Test®, Kato-Katz, Hoffman-Pons-Janer, Willis and Baermann-Moraes coprologic methods for the detection of human parasitosis

This study compares the diagnostic accuracy of the TF-Test® (TFT) for human parasitosis with results obtained using the traditional Kato-Katz (KK), Hoffman-Pons-Janer (HPJ), Willis and Baermann-Moraes (BM) techniques. Overall, four stool samples were taken from each individual; three alternate-day TFT stool samples and another sample that was collected in a universal container. Stool samples were taken from 331 inhabitants of the community of Quilombola Santa Cruz. The gold standard (GS) for protozoa detection was defined as the combined results for TFT, HPJ and Willis coproscopic techniques; for helminth detection, GS was defined as the combined results for all five coproscopic techniques (TFT, KK, HPJ, Willis and BM). The positivity rate of each method was compared using the McNemar test. While the TFT exhibited similar positivity rates to the GS for Entamoeba histolytica/dispar (82.4 percent) and Giardia duodenalis (90 percent), HPJ and Willis techniques exhibited significantly lower positivity rates for these protozoa. All tests exhibited significantly lower positivity rates compared with GS for the diagnosis of helminths. The KK technique had the highest positivity rate for diagnosing Schistosoma mansoni (74.6 percent), while the TFT had the highest positivity rates for Ascaris lumbricoides (58.1 percent) and hookworm (75 percent); HPJ technique had the highest positivity rate for Strongyloides stercoralis (50 percent). Although a combination of tests is the most accurate method for the diagnosis of enteral parasites, the TFT reliably estimates the prevalence of protozoa and selected helminths, such as A. lumbricoides and hookworm. Further studies are needed to evaluate the detection accuracy of the TFT in samples with varying numbers of parasites.

Infection Status of Estuarine Fish and Oysters with Intestinal Fluke Metacercariae in Muan-gun, Jeollanam-do, Korea

The source of human infection with intestinal flukes was surveyed in estuarine fishes, including the dotted gizzard shad, common sea bass, common blackish goby, redlip mullet, black sea bream, and oyster collected from Muan-gun, Jeollanam-do, Korea during August and September 2007. Collected fishes and oysters were artificially digested in pepsin-HCl solution and examined under a stereomicroscope. In 36 shads (Konosirus punctatus) and 20 basses (Lateolabrax japonicus) examined, Heterophyopsis continua metacercariae were found in 58.3% and 100%, and their average numbers were 12.0 and 6.3 per infected fish, respectively. In 34 gobies (Acanthogobius flavimanus) examined, metacercariae of H. continua were detected in 79.4%, Stictodora lari in 97.1%, and Acanthotrema felis in 92.1%, and their average numbers were 45.8, 189.3, and 235.3 per infected fish, respectively. In 37 redlip mullets (Chelon haematocheilus), Heterophyes nocens metacercariae were found in 56.8%, Pygidiopsis summa in 94.6%, and Stictodora fuscata in 45.9%, and the average metacercarial densities were 17.4, 31.3, and 35.1 per infected fish, respectively. In 30 black sea breams (Acanthopagrus schlegeli) and 45 oysters (Crassostrea gigas) examined, no metacercariae were detected. From the above results, it has been confirmed that the dotted gizzard shad, common sea bass, common blackish goby, and redlip mullet from Muan-gun, Jeollanam-do, Korea are infected with the metacercariae of heterophyid flukes.

Gastrointestinal parasites in goats from Monte Castelo, Santa Catarina, Brazil / Parasitas gastrintestinais em caprinos de Monte Castelo, Santa Catarina, Brasil

This study was carried out with the aim of estimating the degree of gastrointestinal helminth infection in goats on the Northern Plateau of Santa Catarina. Twelve young females and 11 adult females were used. Every 28 days, feces samples were taken to quantify the nematode eggs per gram of feces (EPG). Larval culturing was performed on a pool of positive samples from the same group. The fecal egg counts (FECs) ranged from zero to 10,400 EPG in the young group and zero to 7,600 EPG in the adult group. The mean FECs were between 583.3 and 4441.7 in the young group and between 418.2 and 2181.8 in the adult group. Eggs of the order Strongylida and genera Moniezia and Toxocara, and oocysts of Coccidia, were observed. The young animals were more affected and Haemonchus was the most prevalent genus in the samples.

Este trabalho foi realizado com o objetivo de estimar o grau de infecção dos helmintos gastrintestinais em um rebanho caprino criado no Planalto Norte Catarinense. Foram utilizadas 12 fêmeas jovens e 11 adultas, das quais, a cada 28 dias, foram coletadas amostras de fezes diretamente do reto, totalizando 12 coletas, para quantificação de ovos por grama de fezes (OPG) e cultivo de larvas através de "pool" das amostras positivas do mesmo grupo. A contagem de OPG variou de zero a 10.400 nos animais jovens e de zero a 7.600 nos adultos. As médias do OPG entre as coletas foram de 583,3 a 4.441,7 no grupo jovem e de 418,2 a 2.181,8 nos adultos, sendo observados ovos da ordem Strongylida, dos gêneros Moniezia e Toxocara, bem como oocistos de coccídeos. Os animais mais jovens foram os mais acometidos, sendo o gênero Haemonchus o mais prevalente.

Enteric parasites in HIV-1/AIDS-infected patients from a Northwestern São Paulo reference unit in the highly active antiretroviral therapy era / Enteroparasitas em pacientes infectados pelo HIV-1/AIDS em uma unidade de referência do noroeste paulista na era da terapia antirretroviral de alto impacto

INTRODUCTION: We describe the epidemiology of intestinal parasites in patients from an AIDS reference service in Northeastern São Paulo, Brazil. METHODS: Retrospective evaluation was done for all HIV-1/AIDS-positive patients whose Hospital de Base/São José do Rio Preto laboratorial analysis was positive for enteroparasites after diagnosis of HIV-1 infection, from January 1998 to December 2008. Statistical analysis was performed using the R statistical software version 2.4.1. The level of significance adopted was 5 percent. RESULTS: The most frequent protozoan was Isospora belli (4.2 percent), followed by Giardia lamblia (3.5 percent), Entamoeba coli (2.8 percent), and Cryptosporidium parvum (0.3 percent). Ancylostoma duodenale (1.4 percent) was the most frequently detected helminth, while Taenia saginata and Strongiloides stercoralis were found in 0.7 percent of the samples. The results showed that diarrhea was significantly associated with giardiasis and isosporiasis. However, no association was observed between CD4+ cell counts, viral load, and the characteristics of any particular parasite. CONCLUSIONS: Our data may be useful for further comparisons with other Brazilian regions and other developing countries. The data may also provide important clues toward improving the understanding, prevention, and control of enteric parasites around the world.

INTRODUÇÃO: Descrevemos a epidemiologia de enteroparasitoses em pacientes de um serviço de referência de AIDS, no noroeste paulista, Brasil. MÉTODOS: Durante o período de janeiro de 1998 a dezembro de 2008, foi realizado este estudo retrospectivo por meio da análise dos prontuários dos pacientes diagnosticados com HIV-1/AIDS atendidos no Ambulatório de Doenças Infecto-Parasitárias do Hospital de Base, São José do Rio Preto, São Paulo. As análises estatísticas foram realizadas usando a versão 2.4.1 do software estatístico R. O nível de significância adotado foi de 5 por cento. RESULTADOS: O protozoário mais frequente foi o Isospora belli (4,2 por cento), seguido da Giardia lamblia (3,5 por cento), Entamoeba coli (2,8 por cento) e Criptosporidium parvum (0,3 por cento). O Ancylostoma duodenalis (1,4 por cento) foi o helminto mais detectado, enquanto a Taenia saginata e o Strongiloides stercoralis foram observados em 0,7 por cento das amostras. Os resultados mostraram que a diarreia foi significativamente associada com giardíase e isosporíase. Entretanto, nenhuma associação foi observada entre as contagens de células T CD4+, carga viral e da característica de qualquer parasita em particular. CONCLUSÕES: Nossos dados podem ser úteis para futuras comparações com outras regiões do Brasil e outros países em desenvolvimento. Os dados também podem fornecer pistas importantes para a melhoria da compreensão, prevenção e controle de parasitas entéricos em todo o mundo.

Contaminação parasitária de solo em praças públicas da zona leste de São Paulo, SP - Brasil e a associação com variáveis metereológicas / Soil contamination with parasites in public squares in the east zone of Sao Paulo, Brazil and the association with meteorological variables

Vários estudos têm demonstrado a contaminação de ambientes públicos abertos à comunidade por parasitos com potencial zoonótico e propagadores de infecções humanas. De acordo coma Organização Mundial da Saúde, as helmintíases transmitidas pelo solo (Soil-transmitted helminthiases – STH) estão entre as 17 neglected tropical diseases e atingem mais de um bilhão de pessoas das regiões mais pobres do mundo. Neste estudo, verificou-se a contaminação por parasitos em praças públicas da zona leste da cidade de São Paulo, Brasil, no período de setembro de2008 a outubro de 2009, e avaliou-se a existência de relação entre esta contaminação e as variáveis precipitação e temperatura. As amostras, coletadas em dez localidades públicas, foram processadas pela técnica de flotação em solução saturada de cloreto de sódio. Das 300 amostras analisadas, 83,7por cento revelaram-se positivas, com média de 11 a 2 ovos por grama de peso seco nas praças públicas. Foram mais frequentes os parasitos dos gêneros Toxocara spp e Ascaris spp com 44,5por cento e 34,2por cento, respectivamente. Além deles foram observados ainda: Larvas de Nematoda (16,2por cento), Ancilostomídeos (3,8por cento), Enterobius sp (0,6por cento), Hymenolepis spp (0,4por cento), Capillaria sp (0,2por cento) e Trichuris sp (0,1por cento). Os meses com maior pico de encontro de ovos férteis, ovos inférteis, cistos e larvas destes parasitos foram os da estação chuvosa, ou seja, de outubro a março, sendo maiores os índices de ovos férteis. As variáveis precipitação e temperatura tiveram correlação com o númerototal de ovos viáveis e/ou inviáveis (p igual 0,02 e 0,09). Estes dados indicam a existência de risco de contaminação parasitária nas praças públicas estudadas, sendo maior nos períodos com índices mais altos de precipitação e elevada temperatura, de acordo com a Organização Mundial da Saúde.

Several studies have demonstrated the contamination of public places with parasites with zoonotic potential and propagators of human infections. The soil-transmitted helminths are among the seventeen “Neglected Tropical Diseases”, according to World Health Organization, and affect more than one billion people in the poorest regions of the world. We studied the contamination by parasites in public squares in the eastern region of the city of São Paulo, Brazil, between September 2008 and October 2009, and evaluated whether there is a relationship between this contamination and the variables of precipitation and temperature. The samples, collected from ten public localities, were processed by the flotation technique in saturated solution of sodium chloride. Of the 300 samples tested, 83.7% were positive. An average from 11 to 2 eggs per gram dry weight was found. The parasitesmore often found were of the genus Ascaris spp and Toxocara spp with proportions of 44.5% and 34.2%, respectively. In addition, Nematode Larvae (16.2%), Hookworm (3.8%), Enterobius sp (0.6%), Hymenolepis spp (0.4%), Capillaria sp (0.2%) and Trichuris sp (0.1%) were also observed. Higher prevalence of fertile eggs, infertile eggs, cysts, and larvae of the parasite occurred in the rainy seasonwhich lasts from October to March, of these the most prevalent were fertile eggs. The precipitation and temperature variables were correlated with the total number of viable and / or nonviable eggs (p= 0.02 and 0.09).

Evaluación de la posible asociación entre la presencia de parásitos intestinales y Helicobacter pylori en población infantil de la etnia Warao, Venezuela / Evaluation of the possible association between the presence of intestinal parasites and Helicobacter pylori in children of ethnic Warao

Las infecciones por microorganismos gastrointestinales constituyen hoy en día una de las principales causas de morbilidad y mortalidad en países en vías de desarrollo. Nos planteamos como objetivo evaluar la posible asociación entre la presencia de parásitos intestinales y la infección por Helicobacter pylori, y el comportamiento de anticuerpos séricos y secretores en una población infantil de la etnia Warao del Edo. Delta Amacuro, Venezuela. La presencia de parásitos se determinó por examen microscópico directo de las heces. Los niveles séricos de IgE total, IgG anti H. pylori e IgA anti Giardia duodenalis; y los secretores IgA total y específica a G. duodenalis y H. pylori en muestra de saliva, se determinaron utilizando el método de ELISA. El 65% de los niños estaban parasitados por protozoarios, observándose un 47% de poliparasitismo. Encontramos una mayor seroprevalencia de H. pylori en el grupo de niños no parasitados (46%) comparado con los parasitados (25%) (P<0,05). Sin embargo, los niños seropositivos a H. pylori y parasitados con G. duodenalis mostraron niveles séricos de IgE total mayores que los no parasitados (P<0,01); en contraparte, los niveles de IgA secretora total y especifica a H. pylori y G. duodenalis estaban disminuidos (P<0,05). Es posible que la respuesta inflamatoria generada por Giardia pueda aumentar los niveles de IgE total y disminuir la respuesta de IgA secretora favoreciendo la instauración de la infección por H. pylori.

The infections for gastrointestinal microorganisms represent nowadays one of the major reasons of morbidity and mortality in developing countries. We had evaluated both, the possible association between the presence of intestinal parasites and infection by Helicobacter pylori, and the production of serum and salivary antibodies in Amerindian Warao children from the Orinoco Delta, Venezuela. The prevalence of parasites was determined by faecal examination. The levels of serum antibodies (total IgE, specific anti- H. pylori IgG and anti G. duodenalis IgA) and salivary antibodies (total and specific IgA to G. duodenalis and H. pylori), was determined by ELISA. 65% of the child population was parasitized by protozoos, and a 47% of polyparasitism was observed. We found a major seroprevalence of H. pylori in the group of children not parasitized (46 %) compared with the parasitized ones (25 %) (P<0.05). Nevertheless, the seropositive children to H. pylori and parasitized with G. duodenalis showed levels of total IgE higher than the non parasitized ones (P<0.01); in contrast, levels of total and specific secretory IgA to H. pylori and G. duodenalis were decreased (P<0.05). It is possible that the inflammatory response generated by G. duodenalis infection may increase levels of total IgE and diminish secretory IgA response favoring the establishment of infection by H. pylori.

Intestinal helminthiasis among school children in Ilie, Osun State, Southwest, Nigeria

A cross sectional study of intestinal helminthiasis among school pupils was undertaken in three primary schools in Ilie in Olorunda Local Government Area of Osun state in order to determine the prevalence and intensity of helminthic infections. The relationship between intestinal helminths and anthropometric indices and the factors that could favour the infection were also studied. Faecal samples from three hundred and four (304) randomly selected out of the four hundred and seven (407) school children in the study area were collected and analysed with the semi-quantitative Kato Katz technique and concentrated method. The intensity of infection was classified into light; moderate or high according to World Health Organisation (WHO) thresholds. The overall prevalence rate was 52.0 while five species of intestinal helminths were identified. Ascaris lumbricoides (36.2) was the most common; followed by Hookworm (10.5); Schistosoma mansoni (4); Strongyloides stercoralis (0.7) and Hymenolepis nana (0.7). Multiple helminthic infection were recorded with Ascaris -Hookworm (6.58) having the highest prevalence among the children. Female (56.6) were more infected than male (46.4) and the difference was statistically significant (P=0.0019). Seventeen percent (17) of the children were below the third percentile for weight (wasted) while fourteen percent (14) were below the third percentile for height (stunted). There was a relationship between intensity of infection and wasting since there were fewer underweight pupils (13) with normal stool than those moderately infected (35) (P0.05). There was statistically significant association between type of latrine use and prevalence of infection; and also between water treatment and infection. Periodic surveillance of school children for intestinal helminthiasis should be part of the public health activities while periodic deworming programme should be done routinely as this would reduce intensity of intestinal worm infection among school children

Prevalência e fatores associados às geo-helmintíases em crianças residentes em municípios com baixo IDH no Norte e Nordeste brasileiros / Prevalence and factors associated with geohelminth infections in children living in municipalities with low HDI in North and Northeast Brazil

Para determinar a prevalência de geo-helmintíases e identificar fatores associados a sua ocorrência, foram realizados inquéritos coprológicos em amostra de crianças entre 5 e 14 anos de idade, residentes em dez municípios brasileiros com baixo Índice de Desenvolvimento Humano. Aplicou-se questionário aos responsáveis, obtendo-se informações sócio-econômicas e ambientais e foi feita coleta de fezes. Estimaram-se prevalências de geohelmintos segundo variáveis de interesse e se avaliaram os fatores de risco mediante regressão logística multinível. Das 2.523 crianças estudadas, 36,5 por cento eram portadoras de um ou mais geohelmintos (Ascaris lumbricoides 25,1 por cento; ancilostomídeos 15,3 por cento, Trichuris trichiura 12,2 por cento). A proporção de geo-helmintíases para o conjunto na zona rural foi 45,7 por cento; na urbana, 32,2 por cento. Baixa renda familiar (OR = 1,75; 1,38-2,23), baixa escolaridade materna (OR = 1,69; 1,39-2,06), presença de lixo próximo ao domicílio (OR = 1,50; 1,22-1,84) e maior número de pessoas no domicílio (OR = 1,41; 1,17-1,71) mostraram-se associadas a tais infecções. Conclui-se que a ocorrência destas parasitoses está relacionada às condições sócio-econômicas e evidencia a importância de intervenções públicas direcionadas à melhoria das condições de vida para sua prevenção.

Stool surveys were conducted to estimate the prevalence and identify risk factors for geohelminth infections among children in ten Brazilian municipalities with low human development indices (HDI). Socioeconomic and environmental data were obtained from the children's parents or guardians, and stool samples were examined. The proportion of geohelminth infections according to target variables was calculated. Risk factors were evaluated using multilevel logistic regression. Of the 2,523 children, 36.5 percent were infected with one or more geohelminths (Ascaris lumbricoides, 25.1 percent; hookworm, 15.3 percent; Trichuris trichiura, 12.2 percent). Overall prevalence of geohelminth infections was 45.7 percent in rural areas and 32.2 percent in urban areas. Low family income (OR = 1.75; 1.38-2.23), low maternal schooling (OR = 1.69; 1.39-2.06), presence of garbage near the home (OR = 1.50; 1.22-1.84), and number of individuals in the household (OR = 1.41; 1.17-1.71) were associated with infection. In conclusion, geohelminth infections were closely related to socioeconomic conditions, thus emphasizing the importance of targeted public interventions to improve living conditions as part of sustainable prevention.

Asociación entre geohelmintos y condiciones socioambientales en diferentes poblaciones humanas de Argentina / Associations between geohelminths and socioenvironmental conditions among different human populations in Argentina

OBJETIVOS: Analizar la relación entre las especies de geohelmintos identificadas en poblaciones urbanas, suburbanas y rurales de las Provincias de Buenos Aires y Misiones, Argentina, y los aspectos socioambientales que favorecen la infestación por estos parásitos. MÉTODOS: Estudio transversal. Se analizaron 700 muestras fecales humanas provenientes de 319 familias residentes en una población urbana (LPU) y dos suburbanas (LPS, LPN) de la Provincia de Buenos Aires, y una población rural de la provincia de Misiones (MR), en Argentina. Se colectaron 35 muestras fecales de perros y 205 de tierra, y se completaron encuestas sobre las características socioambientales de las localidades estudiadas. Se utilizaron las técnicas de análisis parasitológicos de Ritchie, Carles Barthelemy, Fülleborn y Kato Katz. RESULTADOS: La frecuencia de parasitosis fue mayor en MR (78,4 por ciento), seguida de las áreas suburbanas LPN (35,0 por ciento) y LPS (25,8 por ciento), y fue menor en la zona urbana LPU (5,7 por ciento). Los ancilostomideos (71,1 por ciento) y Strongyloides stercoralis (22,2 por ciento) se detectaron solamente en MR y Ascaris lumbricoides, Hymenolepis nana y Trichuris trichiura fueron más frecuentes en LPN. Las muestras de heces de perros de Misiones presentaron una mayor frecuencia de parásitos (100 por ciento) que las de las localidades de Buenos Aires, pero el suelo del sector urbano bonaerense resultó más contaminado. Las prácticas de alimentación y defecación poco higiénicas, el hacinamiento, el hábito de no usar calzado y el piso de tierra en las viviendas se asociaron significativamente con una mayor frecuencia de geohelmintos y pseudogeohelmintos intestinales (P < 0,05). CONCLUSIONES: El alto número de casos con infestación múltiple observado tanto en las poblaciones suburbanas como en la rural merece una atención especial y plantea la necesidad de profundizar estudios epidemiológicos que integren los diversos aspectos de este complejo ...

OBJECTIVES: To analyze the relationship between the geohelminth species found in urban, suburban, and rural areas of the Buenos Aires and Misiones provinces of Argentina, and the socioenvironmental conditions that promote infection by these parasites. METHODS: This was a cross-sectional study that analyzed 700 human fecal samples taken from 319 families residing in an urban population (UP) and two suburban ones (SUP1, SUP2) in the Province of Buenos Aires, and a rural one in Misiones (RP). Thirty-five samples of dog feces and 205 earth samples were taken, plus surveys were performed of the socioenvironmental characteristics of the study areas. The Ritchie, Carles-Barthelemy, Fülleborn, and Kato-Katz parasite analysis techniques were used. RESULTS: The highest incidence of parasites was in RP (78.4 percent), followed by the suburban areas SUP1 (35.0 percent) and SUP2 (25.8 percent), and lastly, the urban area (5.7 percent). Ancylostomatidae (71.1 percent) and Strongyloides stercoralis (22.2 percent) were found only in RP, while Ascaris lumbricoides, Hymenolepis nana, and Trichuris trichiura were most frequent in SUP1. The samples of dog feces from the Misiones province had the highest incidence of parasites (100 percent) compared to those from Buenos Aires, but the urban dirt from this city proved to be more contaminated. Poor hygiene habits in food preparation and toileting, overcrowding, walking barefoot, and dwellings with dirt floors were significantly associated with a higher frequency of intestinal geohelminths and pseudogeohelminths (P < 0.05). CONCLUSIONS: The great number of cases of multiple infestations seen among suburban as well as rural populations calls for special attention and underscores the need for more extensive epidemiological studies that take on the different aspects of this complex issue with the goal of implementing more efficient health initiatives and programs.