Objetive: To standardise ELISA technique for Toxocara canis human infection diagnosis by using excreted-secreted antigen prepared in our country. Material and methods: T. canis eggs were collected by incubation with formalin (2%) at 28oC in order to obtain third stage larvae that were freed and incubated in RPMI at 37°C for 7 days; the medium was replaced by a similar one and stored at - 20°C. Antigen was concentrated and protein dosage was made. Sera from patients with toxocariasis and newborns were used as positive and negative controls by ELISA technique, dilutions ¼ to 1/1024. Polystyrene plates were sensitised with antigen in several concentrations and conjugated peroxidase with horseradish IgG, anti human IgG and substrate OPD were used. Absorbance was read with spectrophotometer (Multiskan plus labsystems) at 492 nm. Cut off point was determined by negative sera absorbencies ar...

Objective: To estimate seroprevalence of human toxocariosis in Lima inhabitants. Design: Cross-sectional study, non aleatory selection. Material and methods: To people living in Lima city urban marginal communities, an interview and clinical examination were done and serum samples obtained to detect antibodies against Toxocara by ELISA technique. Stool samples were also obtained to check parasites causing cross reactions with serology. Results: From 553 persons examined 23,3% were reactive. There were no sex differences and ELISA results related to anemia, leucocytosis, eosinophilia or intestinal parasites. People older than 15 yearold had twice the possibility to be reactive. Most frequent symptom in positive individuals was decrease of visual capacity. Most frequent parasites were Blastocystis hominis, Entamoeba coli, Giardia lamblia. Conclusions: Human toxocariosis is frequent in Lima...

Objective: To determine human toxocariosis prevalence in subjects presenting suspicious ocular symptoms. Material and methods: Subjects with symptoms and suspicion of intraocular toxocariosis damage attended at various Lima hospitals ophtalmology services were studied. Blood samples were obtained and Toxocara serology by ELISA technique was done, along with leukocyte counts. An epidemiological questionnaire was also applied to identify behaviors associated to infection risk. Results: Forty-five persons were studied, 19 male and 26 female, 55,6% were reactive by ELISA test. No differences in sex and serology results were observed; among participants between 15 and 45 years old, 63% were reactive. There were no significant differences in the epidemiological factors studied. No association between eosinophilia and serology was observed. Conclusions: Human infection by Toxocara is frequent i...

Objetivos: Evaluar la capacidad de absorción de anticuerpos inespecíficos de antígenos totales de adultos de Fasciola hepatica frente a los de Ascaris suum, para mejorar el serodiagnóstico de toxocarosis humana. diseño: Observacional, descriptivo Institución: Instituto de Medicina Tropical Daniel A. Carrión, Facultad de Medicina, UNMSM. Participantes: Se recolectó sueros de pacientes con toxocarosis, otras helmintiasis y de personas aparentemente sanas. Se preparó antígenos TES de Toxocara canis, de Fasciola hepatica y de Ascaris suum. Intervenciones: SDS-PAGE y western blot. Principales medidas de resultados: Los antígenos fueron analizados por SDS-PAGE y western blot y la capacidad de absorción de anticuerpos inespecíficos mediante ELISA y western blot. Resultados: Por SDS-PAGE y western blot se determinó que el extracto antigénico de F. hepatica posee bandas antigénica...

From December 2007 to June 2008, a parasitological research among the population of Parque Industrial Huaycán, in Ate Vitarte district, province of Lima, Peru was performed, in order to determine the prevalence of intestinal parasites and risk factors as well as to determine the sero-prevalence of human Toxocariosis. The coprological samples were analized by the Direct Method with lugol, rapid Sediment in Lumbrera`s glass, and Kinyoun dye for coccidia; and ELISA technique for sero-diagnose of human Toxocariosis. For soil samples, glass sediment and the Baermann-Lumbrera`s technique were used. The Graham method was used for the diagnosis of enterobiosis. Prevalence of enteroparasitism was 74.24%. The most prevalent species of pathogenic protozoa were: Blastocystis hominis Brumpt, 1912 (52.51%) and Giardia lamblia (Lamb, 1859) (18.16%); and among helminths, Enterobius vermicularis Limaeus...

Objective: To conduct metaanalysis by reviewing bibliographic references published during the last 20 years that directly or indirectly compared serologic and parasitologic diagnostic methods for Strongyloides stercoralis infection. Material and methods: We tried to build a tetracoric table to obtain values of serology sensitivity and specificity, choosing parasitologic methods as gold standard. Finally, those references that compared ELISA with parasitologic methods were selected and information was obtained to calculate positive and negative predictive values. Results: Twenty-five references were chosen by applying selection criteria. Positive and negative predictive values were 85,33% and 97,83%, respectively. Conclusion: These results show the potential usefulness of ELISA method as a screening test for strongyloidiasis, in order to facilitate studies in populations exposed to this p...

Objetivos: Determinar niveles de Elisa anti-IgE, sensibilidad, especificidad y valor predictivo en pacientes con equinococosis quística. Demostrar la correlación entre los niveles de IgE específicos con la respuesta al tratamiento médico con albendazol. Diseño: Estudio cuasiexperimental con grupo control para la prueba de Elisa IgE y preexperimento con preprueba y posprueba en un solo grupo, para diagnóstico y seguimiento postratamiento. Institución: Instituto de Medicina Tropical Daniel A. Carrión, Facultad de Medicina, UNMSM. Participantes: Pacientes sanos y con equinococosis quística y otras helmintiasis. Intervenciones: Para Elisa, se utilizó suero de 5 pacientes con equinococosis quística; para sensibilidad y especificidad el suero de 30 pacientes sanos. Para reacciones cruzadas, 16 pacientes con otras helmintiasis y para el diagnóstico y seguimiento postratamiento, el s...

Objetivos: Definir el perfil clínico-epidemiológico de pacientes con estrongiloidiasis atendidos en el Instituto de Medicina Tropical, entre los años 2005 y 2011. Diseño: Estudio prospectivo de serie de casos. Institución: Instituto de Medicina Tropical, UNMSM. Participantes: Pacientes con diagnóstico de estrongiloidiasis. Intervenciones: A 31 pacientes con diagnóstico de estrongiloidiasis, 20 varones y 11 mujeres, se les hizo ficha clínico- epidemiológica, examen de heces seriado con método de Baerman y sedimentación rápida, hemograma completo. Principales medidas de resultados: Porcentajes de síntomas y signos, procedencia, vivir o haber estado en la selva y recuento de eosinófilos. Resultados: La edad promedio de los 31 pacientes fue 40 años, 41,9% nació en la selva, 32,2% en la costa y 25,8% en la sierra; 25,8% vivía en la selva, 61,2% vivía en Lima, pero en algún ...

A bibliographic review was done to update and systematize information on Toxocara human infection. Transmission mechanisms, epidemiology, clinical forms, diagnostic methods and treatment are described. Its importance as an infectious cause of blindness in young people that is potentially preventible and curable by early diagnosis is emphasized. Proposal is done to establish epidemiological surveillance, improve current laws to reduce transmission risk to the general population and increase knowledge on this infection in Peru.

Objective: To standardize ELISA technique for human Strongyloides stercoralis infection diagnosis. Material and methods: A crude antigen was prepared using filariform larvae obtained from positive stool samples cultured with charcoal. Harvested larvae were crushed by sonication and washed by centrifugation in order to obtain protein extracts to be used as antigen. Final protein concentration was 600 µg/mL. Several kinds of ELISA plates were tested and antigen concentration, sera dilution, conjugate dilution and cut off were determined to identify infection. Sera from patients with both hyperinfection syndrome and intestinal infection demonstrated by parasitological examination were positive controls and sera from people living in non-endemic areas with no infection demonstrated by parasitological examination were negative controls. Results: Best values were 5 µg/mL for antigen, 1/64 fo...

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%); al...

OBJECTIVE: To assess the prevalence of paragonimosis among elementary school students from three villages of Condebamba valley, Cajamarca - Perú. MATERIAL AND METHODS: 77 school-age children underwent parasitologic examination in stools, skin test and counterimmunoelectrophoresis in those positive for skin reactivity. RESULTS: From 77 skin tests performed, 2 were positive (2,6%), which were also positive by counterimmunoelectrophoresis. All 77 stool samples were negative for Paragonimus eggs. CONCLUSION: These results showed a decreasing prevalence of human paragonimiasis among Condebamba valley children.

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 he...

OBJECTIVE: To determine the presence of Acanthamoeba genus in several Ica city (south of Lima) water sources. MATERIAL AND METHODS: Thirty-one samples from 7 natural water sources (lagoons) and 24 artificial sources (wells, tanks for rehabilitation therapy, reservoirs and cisterns) were examined during May 1997 in several points of the city. Samples were sowed in Agar Myast and in Agar Napolitan, incubated at 37°C and checked after 10 days. Positive samples were inoculated to immunocompetent mice by intranasal route; resultant lesions were cultured again following the same procedure. RESULTS: In 11 samples (35,5%) Acanthamoeba cysts were isolated, 6 from natural sources and 5 from artificial sources; among negative samples only one came from natural source and the other 19 came from artificial sources inside homes or from the local hospital. OR =22,8 was obtained for exposition to natur...

Objetivo: Realizar una evaluación inmunogénica de la EST del veneno de B. atrox y determinar su grado de reactividad contra los venenos de las principales serpientes venenosas del país. Materiales y métodos: Se inmunizaron conejos albinos (2.5 Kg) con 150 μg de la enzima purificada basándose en protocolos estandarizados en nuestro laboratorio. Una vez obtenido el suero hiperinmune anti-EST, se analizaron los patrones de reactividad entre el suero experimental y la enzima purificada, así como contra los venenos totales de Bothrops atrox, Bothrops brazili, Lachesis muta y Crotalus durissus, empleando la técnica de ELISA. Resultados: Se obtuvo, al final del protocolo de inmunización, un suero anti-EST con un título de 64000. Por otro lado, los anticuerpos producidos reaccionaron de forma cruzada con los venenos completos de B. atrox (9.9%) y B. brazili (9.6%), y menor intensidad c...

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 μg 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...

Objetivo: Realizar una evaluación inmunogénica de la EST del veneno de B. atrox y determinar su grado de reactividad contra los venenos de las principales serpientes venenosas del país. Materiales y métodos: Se inmunizaron conejos albinos (2.5 Kg) con 150 μg de la enzima purificada basándose en protocolos estandarizados en nuestro laboratorio. Una vez obtenido el suero hiperinmune anti-EST, se analizaron los patrones de reactividad entre el suero experimental y la enzima purificada, así como contra los venenos totales de Bothrops atrox, Bothrops brazili, Lachesis muta y Crotalus durissus, empleando la técnica de ELISA. Resultados: Se obtuvo, al final del protocolo de inmunización, un suero anti-EST con un título de 64000. Por otro lado, los anticuerpos producidos reaccionaron de forma cruzada con los venenos completos de B. atrox (9.9%) y B. brazili (9.6%), y menor intensidad c...

OBJECTIVES: To assess the prevalence of E. histolytica and E. dispar in a marginal population of Callao, Lima, using ELISAs. MATERIAL AND METHODS: Two ELISAs were used, one of them for both Entamoeba species (Entamoeba-ELISA), and an E. histolytica-specific ELISA. RESULTS: 128 stool samples from randomized Callao inhabitants were microscopically examined. Thirteen (10%) were microscopically diagnosed as having E. histolytica or E. dispar infection; and 7 (6%) were positive to Entamoeba–ELISA (sensitivity = 54%). Five of the 115 samples without cysts of E. histolytica or E. dispar were Entamoeba ELISA positive (specificity = 96%). All samples were negative to the E. histolytica-specific ELISA. CONCLUSIONS: The correlation between the microscopical identification and Entamoeba-ELISA was not good, it may be due to an overvaluation of the morphological diagnosis.

Objective: To estimate intestinal coccidiae infection prevalence of in asymptomatic children from a marginal community in Lima. Material and Methods: Stool samples were collected from 79 asymptomatic children aged 7 months through 7 year-old from Asentamiento Humano “Las Casuarinas de Villa”. Direct smear and colored frotis by Kinyoun technique were prepared. Another portion was placed in small bottles with potasium bicromatum 2,5% to obtain sporulation. After 10 days, frotis were colored by Kinyoun. Results: Direct smear detected one sample with Cryptosporidium (1,3%). In frotis colored before sporulation, 3 with Cryptosporidium (3,8%) were found and one with Isospora belli (1,3%); in frotis colored post-sporulation 6 samples with Cryptosporidium (7.59%) were detected and one with Isospora belli. Conclusion: Sporulation increases Cryptosporidium detection.