Objective. To estimate frequency of toxocariosis in Lima Region. Methods. During 2013, a non- randomized serological survey was performed by Elisa technique in four Lima Region provinces’ (Cajatambo, Canta, Huaral and Yauyos) inhabitants. Sera samples were obtained by DIRESA Lima and Regional Reference Laboratory of Public Health workers and processed at Tropical Medicine Institute “Daniel A. Carrion” of Universidad Nacional Mayor de San Marcos, Lima, Peru. Results. From 442 sera samples obtained 142 (32.1%) were positive to Toxocara; 54% of participants were female, 31% were between 31-59 years, 45% had a dog or cat at home. There were no significant differences between serology and ages or sex or in having dog or cats. Conclusions. Toxocariosis is frequent in Lima Region inhabitants. It is necessary to perform representative studies to determine prevalence of this infection.

Objetivo. Estimar la frecuencia de toxocariosis en la Región Lima. Métodos. Durante el año 2013, se realizó una encuesta serológica no aleatorizada mediante la técnica de Elisa en pobladores de cuatro provincias de la Región Lima (Cajatambo, Canta, Huaral y Yauyos). Las muestras fueron obtenidas por personal de la DIRESA Lima, del Laboratorio de Referencia Regional en Salud Pública y procesadas en el Instituto de Medicina Tropical “Daniel A. Carrión” de la Universidad Nacional Mayor de San Marcos, Lima, Perú. Resultados. Se recolectaron 442 muestras de suero, de las cuales 142 (32,1%) fueron positivas a toxocara. El 54% de participantes fue de sexo femenino, 31% tenía entre 31 y 59 años, 45% manifestó tener un perro o un gato en su hogar. No hubo diferencias significativas entre los resultados de serología y las edades y sexos ni tenencia de canes o gatos en la población estudiada. Conclusiones. La toxocariosis es frecuente en la población de la Región Lima, por lo que es necesario realizar estudios representativos para determinar la prevalencia de esta infección.

The immunogenicity of Bothrops atrox, "jergón", venom was studied using ELISA and Western Blot methods, as well as cross-reactivity patterns against venoms of Bothrops brazili, Lachesis muta and Crotalus durissus. For this purpose, New Zealand white rabbits (2 kg aprox) were immunized with four 500 µg doses of B. atrox venom in a period of 90 days. Antibody production was followed using ELISA technique, and title of hiper-immune serum was determined at the end of immunization protocol. Additionally, electrophoretic patterns of venoms were analyzed by SDS-PAGE and venom reactivity against obtained serum by ELISA and Western Blot. Immunization schedule allowed a pronounced antibody production since day 20 of protocol. At the end of process, serum title was 256000, which demonstrated both efficacy and usefulness of the developed procedure. On the other hand, studied venoms showed a heterogenic protein composition according to their electrophoretic patterns, whereas cross-reactivity values of 23,7%, 4,0% and 1,8% were obtained between B. atrox venom and B. brazili, L. muta and C. durissus venoms, respectively, using immunoenzymatic methods. According to our results, this procedure constitutes an initial step for further assays directed to optimization in immunoserum production for envenoming treatment and development of kits for diagnosis and species identification of snakes.

Se estudió la inmunogenicidad del veneno de la serpiente Bothrops atrox, "jergón", utilizando los métodos inmunoenzimáticos de ELISA y Western Blot, así como los patrones de reactividad cruzada empleando los venenos de las serpientes Bothrops brazili, Lachesis muta y Crotalus durissus. Para este fin se inmunizaron conejos albinos Nueva Zelanda (2 kg aprox) con cuatro dosis de 500 ¼g del veneno de B. atrox en un periodo de 90 días. La producción de anticuerpos fue monitoreada mediante la técnica de ELISA, determinándose el título del suero hiperinmune obtenido al final del protocolo de inmunización. Adicionalmente se analizaron los patrones electroforéticos de los venenos en estudio mediante PAGE-SDS y su reactividad frente al suero obtenido mediante ELISA y Western Blot. El esquema de inmunización utilizado permitió una producción sostenida de anticuerpos a partir del día 20 del protocolo. Finalizado este proceso, el título del suero fue calculado en 256000, lo cual mostró la eficacia y practicidad del procedimiento desarrollado. Por otro lado, los venenos estudiados mostraron una heterogeneidad en su composición proteica a partir del análisis de sus patrones electroforéticos, mientras que a partir de los estudios inmunoenzimáticos, se pudo obtener valores de reactividad cruzada entre el veneno de B. atrox y los venenos de B. brazili, L. muta y C. durissus, de 23,7%, 4,0% y 1,8%, respectivamente. Los resultados obtenidos constituyen el paso inicial para posteriores ensayos dirigidos a la optimización en la producción de inmunosueros para el tratamiento del envenenamiento, así como para el desarrollo de kits de diagnóstico e identificación de especies de serpiente.

Lophomonas sp. is a habitual parasite of the intestinal tract of the cockroaches and that is not recognized as pathogenic human being. Nevertheless, in the world literature are few reports of Lophomonas sp. in respiratory tract secretions in patients with severe pulmonary disease, mostly in adults. We present evidences of Lophomonas sp. in the respiratory low tract of children attended in the national reference center of paediatric diseases of Lima, Peru, in the period 2009- 2010. We found six cases, 4/23 from broncoalveolar lavage and 2/794 from tracheal aspirate samples of children. Five of them had pneumonia and one atelectasis, four were hospitalized in the intensive care unit. Increase knowledge about the presence of this organism in respiratory infections is needed, as its real pathogenic role.

Lophomonas sp. es un parásito habitual del tracto intestinal de las cucarachas y que no es reconocido como patógeno humano. Sin embargo, en la literatura mundial existen escasos reportes de Lophomonas sp. en secreciones del tracto respiratorio en pacientes con enfermedad pulmonar grave, principalmente en adultos. Presentamos evidencias de Lophomonas sp. en el tracto respiratorio inferior de niños atendidos en el centro de referencia nacional de enfermedades pediátricas de Lima, Perú, en el periodo 2009-2010. Se encontró seis casos, 4/23 provenientes de muestras de lavado broncoalveolar y 2/794 muestras de aspirado traqueal de niños. Cinco de ellos tuvieron neumonía y uno atelectasia, cuatro estuvieron en la unidad de cuidados intensivos. Es necesario conocer más sobre la presencia de este organismo en infecciones respiratorias así como su rol patogénico real.

Human toxocarosis is an important parasitic zoonosis caused by larval stages of Toxocara species, the roundworms from dogs and cats. Larval migration through different soft tissues in the human generates several clinical entities in the patient, such as visceral larva migrans, ocular toxocarosis, and neurotoxocarosis. Definitive diagnosis by histopathological methods is very difficult or almost impossible and, nowadays, the diagnosis is usually made by clinical signs/symptoms, epidemiological background of the patient and the use of hematological and immunological tests which finally help to confirm the clinical suspicion of the illness. The purpose of this paper was to update the available knowledge on the use of different tools for both the diagnosis and following up of human toxocarosis.

La toxocarosis humana es una importante zoonosis parasitaria causada por formas larvarias de especies del género Toxocara, un parásito nematodo de los perros y los gatos. La migración de la larva por los diferentes tejidos blandos en el ser humano genera una serie de entidades clínicas en el paciente, tales como el síndrome de larva migrans visceral, la toxocarosis ocular y la neurotoxocarosis. El diagnóstico definitivo es mediante la histopatología en biopsias, pero resulta ser casi imposible de realizar y actualmente su diagnóstico se establece mediante el análisis de la sintomatología clínica, los antecedentes epidemiológicos del paciente y el uso de pruebas hematológicas e inmunológicas de laboratorio que son las que finalmente ayudan a confirmar la sospecha clínica de la enfermedad. El propósito del presente artículo es actualizar los conocimientos que se tienen sobre el uso de las diferentes herramientas para establecer el diagnóstico y el monitoreo de la toxocarosis humana.

Lophomonas sp. is a habitual parasite of the intestinal tract of the cockroaches and that is not recognized as pathogenic human being. Nevertheless, in the world literature are few reports of Lophomonas sp. in respiratory tract secretions in patients with severe pulmonary disease, mostly in adults. We present evidences of Lophomonas sp. in the respiratory low tract of children attended in the national reference center of paediatric diseases of Lima, Peru, in the period 2009- 2010. We found six cases, 4/23 from broncoalveolar lavage and 2/794 from tracheal aspirate samples of children. Five of them had pneumonia and one atelectasis, four were hospitalized in the intensive care unit. Increase knowledge about the presence of this organism in respiratory infections is needed, as its real pathogenic role.

Lophomonas sp. es un parásito habitual del tracto intestinal de las cucarachas y que no es reconocido como patógeno humano. Sin embargo, en la literatura mundial existen escasos reportes de Lophomonas sp. en secreciones del tracto respiratorio en pacientes con enfermedad pulmonar grave, principalmente en adultos. Presentamos evidencias de Lophomonas sp. en el tracto respiratorio inferior de niños atendidos en el centro de referencia nacional de enfermedades pediátricas de Lima, Perú, en el periodo 2009-2010. Se encontró seis casos, 4/23 provenientes de muestras de lavado broncoalveolar y 2/794 muestras de aspirado traqueal de niños. Cinco de ellos tuvieron neumonía y uno atelectasia, cuatro estuvieron en la unidad de cuidados intensivos. Es necesario conocer más sobre la presencia de este organismo en infecciones respiratorias así como su rol patogénico real.

Human toxocarosis is an important parasitic zoonosis caused by larval stages of Toxocara species, the roundworms from dogs and cats. Larval migration through different soft tissues in the human generates several clinical entities in the patient, such as visceral larva migrans, ocular toxocarosis, and neurotoxocarosis. Definitive diagnosis by histopathological methods is very difficult or almost impossible and, nowadays, the diagnosis is usually made by clinical signs/symptoms, epidemiological background of the patient and the use of hematological and immunological tests which finally help to confirm the clinical suspicion of the illness. The purpose of this paper was to update the available knowledge on the use of different tools for both the diagnosis and following up of human toxocarosis.

La toxocarosis humana es una importante zoonosis parasitaria causada por formas larvarias de especies del género Toxocara, un parásito nematodo de los perros y los gatos. La migración de la larva por los diferentes tejidos blandos en el ser humano genera una serie de entidades clínicas en el paciente, tales como el síndrome de larva migrans visceral, la toxocarosis ocular y la neurotoxocarosis. El diagnóstico definitivo es mediante la histopatología en biopsias, pero resulta ser casi imposible de realizar y actualmente su diagnóstico se establece mediante el análisis de la sintomatología clínica, los antecedentes epidemiológicos del paciente y el uso de pruebas hematológicas e inmunológicas de laboratorio que son las que finalmente ayudan a confirmar la sospecha clínica de la enfermedad. El propósito del presente artículo es actualizar los conocimientos que se tienen sobre el uso de las diferentes herramientas para establecer el diagnóstico y el monitoreo de la toxocarosis humana.

O propósito do presente trabalho foi estimar a soroprevalência da toxocaríase humana em três comunidades andinas do Nordeste de Lima, Peru. Foi estudado um total de 303 pessoas, entre crianças e adultos. Foram coletadas amostras de sangue para a detecção de anticorpos anti-Toxocara e para a análise hematológica, além de amostras fecais para o exame parasitológico. A soroprevalência geral da população foi de 20,46% com proporção significativamente maior de positividade em crianças de um a 10 anos (p = 0,034). Das pessoas com sorologia positiva, 32,26% apresentavam sintomas respiratórios, 22,58% moléstias hepáticas, 17,74% manifestações oculares, 14,51% dor abdominal, e 4,84% sinais cutâneos. Além disso, 79,03% das pessoas com sorologia positiva tinham pelo menos algum parasito intestinal com associação significativa (p < 0.05). A presença de cachorros dentro das casas, história de pica ou geofagia e o uso dos lugares públicos também estiveram presentes nesta população, mas o ultimo deles só esteve associado com a sorologia positiva (p < 0.05). Conclui-se que existem evidências clínicas, sorológicas e epidemiológicas de infecção por larvas de Toxocara na população estudada.

The aim of this study was to assess the seroprevalence of human toxocariasis in three Andean communities from the Northeast of Lima, Peru. A total of 303 subjects including children and adults were studied and blood samples were collected to detect anti-Toxocara antibodies by ELISA-IgG test and by hematological examination; stool samples were collected also for parasitological examination. The overall seroprevalence of toxocariasis observed in the total population was 20.46%, with a significant high proportion in children from one to 10 years old (p = 0.034). Among the subjects with positive serology, 32.26% of them had respiratory disturbances, 22.58% hepatomegaly, 17.74% ocular signs or symptoms, 14.51% abdominal pain, 9.68% neurological involvement, and 4.84% cutaneous signs, but none of these clinical features were associated to a positive serology by multivariate analysis. Furthermore, 79.03% of seropositive subjects also harbored at least one intestinal parasite, which was associated to a positive serology (p < 0.05). The presence of pets within the houses, a previous history of pica or geophagia and the use of public places were also present in this population, but only the latter was associated to the serology (p < 0.05). In conclusion, clinical, serological, and epidemiological evidences for larval Toxocara infection were found in the studied population.

O objetivo do presente estudo foi estimar a soroprevalência da infecção por Toxocara em população geral da cidade de Yurimaguas, Peru. Entre os meses de Março e Agosto de 2008, foi estudado um total de 300 pessoas por exame imunológico mediante Toxocara ELISA-IgG teste. Uma ficha clínico-epidemiológica foi utilizada para avaliar a sintomatologia e os fatores de risco associados à toxocaríase. A freqüência geral de anticorpos na população foi de 35,66% com proporção significativamente maior de positividade em meninos de um a 10 anos (p < 0.001). A avaliação clínica revelou que 95.33% do grupo de soropositivos apresentava algum tipo de sintomatologia associada à toxocaríase: 66,36% cefaléia, 63,55% sintomas respiratórios, 54,21% dor abdominal, 40,19% sinais cutâneos e 36,45% manifestações oculares e quase todos estes sinais foram estatisticamente associados ao resultado da sorologia (p < 0.001). Além disso, 56,07% das pessoas com sorologia positiva tinham pelo menos algum parasito intestinal patogênico e com predominância de helmintos, mas sem nenhuma associação significativa (p = 0.334). A análise dos fatores de risco mostrou que o uso de lugares públicos e história de geofagia tiveram significativa associação com a sorologia positiva (p < 0,001). Conclui-se que existem evidências clínicas, sorológicas e epidemiológicas de infecção por Toxocara na população estudada e futuros estudos são necessários para avaliar este sério problema de saúde pública.

The aim of this study was to determine the seroprevalence of the infection by Toxocara in the general population of the Amazonian city of Yurimaguas, Peru. From March to August 2008, a total of 300 subjects were sampled and tested by means of a Toxocara ELISA-IgG test. A clinical and epidemiological questionnaire was used to assess the symptomatology and risk factors associated with human toxocariasis. The overall rate of seropositivity was 35.66%, with a significant high proportion in children (p < 0.001). The clinical evaluation revealed that 95.33% of the seropositive group had some type of symptomatology: headache (66.36%), respiratory compromise (63.55%), abdominal pain (54.21%), cutaneous signs (40.19%) and ocular manifestations (36.45%), and almost all of them were statistically significant (p < 0.001). Furthermore, 56.07% of the seropositive subjects presented at least one intestinal pathogen parasite with predominance of helminthes, but without significant association (p = 0.334). The analysis of risk factors showed only that the use of public places and geophagia exhibited a significant association with the seropositivity (p < 0.001). Clinical, serological and epidemiological findings associated to infection with Toxocara were observed in the present study and future studies should be done to assess this serious health problem.

O propósito do presente estudo foi estimar a freqüência da toxocaríase no distrito de Cauday, Cajamarca, Peru, usando o dot-ELISA teste. Entre junho e outubro de 2005, um total de 256 pessoas foram avaliadas. Coletaram-se amostras de sangue para o teste de dot-ELISA e para o exame hematológico e amostras de fezes para exame parasitológico. A freqüência geral de anticorpos anti-Toxocara observada foi de 44,92%, com maior proporção significativa de positividade em pessoas do sexo masculino. Das pessoas com sorologia positiva, 45,6% apresentavam sintomas respiratórios, 40,44% dores abdominais, 32,35% moléstias hepáticas, 14,7% sinais cutâneos, 13,23% manifestações oculares, 43,38% eosinofilia e todos estes fatores foram estatisticamente associados à sorologia. Entre as pessoas avaliadas 90,23% estavam parasitadas e 92,17% das pessoas com sorologia positiva tinham algum parasito intestinal, sendo os mais freqüentes: Blastocystis hominis (68,38%), Giardia lamblia (28,68%), Hymenolepis nana (20,0%), Ascaris lumbricoides (15,65%), Entamoeba histolytica/E. dispar (13,24%), Cyclospora cayetanensis (4,41%), Cryptosporidium sp. (1,47%), Enterobius vermicularis (0,87%), Strongyloides stercoralis (0,87%), Taenia sp. (0,87%) e Trichuris trichiura (0,87%). A taxa de falsos positivos no teste dot-ELISA foi melhorada pela absorção dos soros com antígenos de A. suum, com diminuição das reações cruzadas. Em conclusão, a toxocaríase humana é altamente freqüente nesta população e fatores de risco como ter um cão/gato, presença dos animais dentro de casa e estória prévia de geofagia foram observados durante o presente estudo.

The aim of this study was to estimate the frequency of human toxocariasis in Cauday district, Cajamarca, Peru, using a dot-ELISA test. From June to October 2005, a total of 256 adult subjects were studied. Blood samples were collected for serology by a dot-ELISA test and for hematological examination. Parasitological examination was also carried out in stool samples to check cross-reactions in the dot-ELISA. The frequency observed was 44.92%, with a significant higher proportion of positivity in male subjects. From subjects with positive serology, 45.6% had respiratory symptoms, 40.44% abdominal pain, 32.35% hepatic symptoms, 14.7% cutaneous signs, 13.23% ocular manifestations, 43.38% eosinophilia, and all of these were statistically associated to serology. Among the population evaluated, 90.23% (231/256) were parasitized. From subjects with positive serology, 92.17% had at least one intestinal parasite and the most frequent were: Blastocystis hominis (68.38%), Giardia lamblia (28.68%), Hymenolepis nana (20.0%), Ascaris lumbricoides (15.65%), Entamoeba histolytica/E. dispar (13.24%), Cyclospora cayetanensis (4.41%), Cryptosporidium sp. (1.47%), Enterobius vermicularis (0.87%), Strongyloides stercoralis (0.87%), Taenia sp. (0.87%), and Trichuris trichiura (0.87%). The rate of false positives in the dot-ELISA test was improved by serum absorption each with A. suum antigens, with a decrease of cross-reactions. In conclusion, human toxocariasis is highly frequent in this population and some risk factors like dog/cat ownership, presence of pets within house, and previous history of geophagia were observed in the present study.

Durante estudo epidemiológico em escola primária do Distrito de Carabayllo (norte de Lima, Peru), 200 crianças (96 do sexo masculino e 104 do feminino, entre cinco e 12 anos de idade) foram selecionadas ao acaso e divididas em dois grupos (grupo positivo e grupo negativo) de acordo com os resultados de teste de ELISA para Toxocara em população total de 646 escolares. Todas as crianças foram analisadas por testes hematológicos para determinar a freqüência de eosinofilia e leucocitose. Adicionalmente, os dados clínicos e epidemiológicos foram analisados para determinar associação com toxocaríase. No grupo de crianças com sorologia positiva 40% tinham eosinofilia em contraste com 19% de crianças com sorologia negativa e esta associação foi estatisticamente.significante (OR = 2,84, p < 0,001). De todos os sinais e sintomas avaliados, somente tosse seca foi mais freqüente e estatisticamente significante no grupo de sorologia positiva (OR = 2,79, p < 0,001). Quase todos os fatores de risco avaliados foram de alta freqüência e estatisticamente associados à sorologia positiva. Em conclusão, a presença de eosinofilia e dos fatores de risco avaliados nesta população foram frequentemente associados à toxocaríase humana.

During a health survey in a primary school from the district of Carabayllo (North of Lima, Peru), 200 schoolchildren (96 male and 104 female between five to 12 years old) were randomly selected and divided in two groups (as positive or negative group), according to the serologic result of the Toxocara ELISA test from a total population of 646 schoolchildren. All children were analyzed by hematologic tests to determinate the frequency of eosinophilia and leukocytosis. Additionally, all clinical and epidemiological data were also analyzed to determine their association with toxocariasis. From group of children with positive serology, 40% had some type of eosinophilia in contrast to 19% of children with negative serology, and their association was statistically significant (OR = 2.84, p < 0.001). From all signs and symptoms evaluated, only 'dry cough' was more frequent and statistically significant in the positive serology group (OR = 2.79, p < 0.001). Almost all risk factors evaluated were highly frequent and statistically associated to the positive serology. In conclusion, the presence of eosinophilia and the risk factors evaluated in this population were frequently associated to human toxocariasis.

O propósito do presente trabalho foi estimar a freqüência da toxocaríase humana em crianças do distrito de Morrope, Lamabayeque, Perú. Nos meses de outubro a dezembro de 2005, 182 escolares (96 meninos e 86 meninas) foram estudados. Coletaram-se amostras de sangue para a análise hematológica e imunológica pelo teste de ELISA-IgG-Toxocara e amostras fecais para o exame parasitológico. A freqüência geral da população foi de 32,4% (59/182) com proporção significativamente maior de positividade nos meninos. Das crianças com resultado positivo ao teste sorológico (52 meninos e sete meninas), 71,2% tinham entre cinco e 10 anos, 77,96% apresentavam sintomas respiratórios, 61,02% apresentavam manifestações oculares, 38,98% apresentavam moléstias hepáticas, 38,98% apresentavam suave ou moderada eosinofília e todos estes sinais foram estatisticamente associados ao resultado da sorologia. A presença de algum parasito intestinal foi observada em 83,5% da população estudada: Blastocystis hominis (53,3%), Giardia lamblia (31,3%), Entamoeba coli (29,1%), Entamoeba histolytica/E. dispar (1,1%), Hymenolepis nana (5,49%), e Ascaris lumbricoides (3,3%), mas estes não tiveram nenhuma associação com a sorologia. A posse de cães e gatos revelou associação estatisticamente significante com a positividade para toxocaríase embora a presença destes animais no domicílio não tenha revelado tal associação. Conclui-se que existem evidências clínicas e sorológicas de infecção por Toxocara na população estudada.

The aim of this study was to estimate the frequency of human toxocariosis in a child population from Morrope district, Lambayeque, Peru. From October to December 2005, 182 school children (96 male and 86 female) were studied. Blood samples were collected for Toxocara ELISA-IgG test and hematological examination. Additionally, stool samples were collected for coproparasitological examination to check cross reactions. We found frequency of positives in 32.4% (59/182) with a significant higher proportion of positivity in male children (p < 0.00001). 71.2% of the children with positive serology (52 male and seven female), were between five and 10 years old, 77.96% had respiratory symptoms, 61.02% had ocular manifestations, 38.98% had hepatic symptoms, 38.98% had mild or moderate eosinophilia, signs statistically associated with seropositivity. 83.5% of studied population had some intestinal parasite, such as: Blastocystis hominis (53.3%), Giardia lamblia (31.3%), Entamoeba coli (29.1%), Entamoeba histolytica/E. dispar (1.1%), Hymenolepis nana (5.49%), and Ascaris lumbricoides (3.3%), but they had not any association with serology results. The ownership of dogs or/and cats were significantly associated with seropositivity to anti-Toxocara antibodies although the presence of such pets within the house was not. In conclusion, clinical and serological evidence of Toxocara infection exists in the studied population.

Objective: To describe the experience with ivermectin and thiabendazole in patients attended at the Tropical Medicine Institute "Daniel A. Carrión"- UNMSM. Material and Methods: During 2001 and 2002, ivermectin (0,2 mg/kg in single dosis) and thiabendazole (25 mg/kg/3days) were administered to 22 (Group 1) and 20 (Group 2) patients with diagnosis of Strongyloides stercoralis in stools. Controls were performed between 20 and 40 days following treatment. Results: Mean age was 21,8 years (SD 22,6) for group 1 and 33,5 years (SD 14,2) for group 2. There were 12 males (54,5%) in group 1 and 7 (35%) in group 2. Ivermectin was 100% efficient while thiabendazole was 95%; only one case needed a second cycle because of high amount of parasites from the beginning; his next control was negative. Most frequent symptoms were diarrhea (71,4%), abdominal pain (61,9%) and epigastric pain (47,6%); all patients felt better after treatment. Only 2 cases (10%) from group 2 referred light nausea during the first day of treatment that disappeared at the second day. Conclusions: Both drugs ratify their efficacy and safety for Strongyloides stercoralis treatment making it necessary to have them in the national petitioner.

Objetivo: Describir la experiencia del uso de ivermectina y tiabendazole en pacientes atendidos en el Instituto de Medicina Tropical "Daniel A. Carrión"- UNMSM. Material y Métodos: Durante los años 2001 y 2002, se administró ivermectina 0,2 mg/kg en dosis única a 22 pacientes (Grupo 1) o tiabendazole 25 mg/kg por 3 días a 20 pacientes (Grupo 2) con diagnóstico de Strongyloides stercoralis en heces. Se efectuó controles entre 20 y 40 días después de administrado el tratamiento. Resultados: El promedio de edades fue 21,8 años (DE 22,6) para el grupo 1 y de 33,5 años (DE 14,2) para el grupo 2. Hubo 12 varones (54,5%) en el grupo 1 y 7 (35%) en el grupo 2. Ivermectina fue 100% eficaz, mientras que tiabendazole lo fue en 95%; sólo un caso requirió un segundo ciclo debido a la alta carga parasitaria inicial; el siguiente control fue negativo. Los síntomas más frecuentes fueron diarreas (71,4%), dolor cólico (61,9%) y dolor epigástrico (47,6%). Todos los pacientes manifestaron mejoría clínica luego del tratamiento. Sólo 2 casos (10%) del grupo 2 manifestaron leve sensación nauseosa durante el primer día del tratamiento, que remitió por completo al segundo día. Conclusiones: Ambos medicamentos ratifican su eficacia y seguridad para ser utilizados en el tratamiento de Strongyloides stercoralis; es necesario disponer de ellos en el petitorio nacional.