Inmunidad anti-cisticerco en una comunidad indígena del occidente venezolano / Anti-Cysticercus Immunity in an Amerindian Community from Western Venezuela

Para determinar la presencia de anticuerpos anti-cisticerco en una comunidad indígena del occidente venezolano, 93 individuos entre 1-78 años de edad fueron estudiados. La detección de anticuerpos anti cisticerco se realizó mediante la técnica inmunoenzimática de ELISA con extractos antigénicos de fluido vesicular de Taenia crassiceps. Los sueros fueron considerados positivos a diluciones ≥ 1:256 y las heces fueron estudiadas mediante examen parasitológico directo y concentrado. El 27,9% de la población presentó inmunidad anti-cisticerco y todos los grupos etarios fueron positivos. No se observaron diferencias estadísticamente significativas en relación al sexo, ni entre los grupos etarios. En el examen físico y en la historia clínica, no se encontraron datos relevantes de una probable alteración funcional en relación a cisticercosis. El porcentaje general de infección parasitaria fue de un 81,5%, con un marcado poliparasitismo de un 64,6%, con predominio de infección por protozoarios. No se detectaron huevos de Taenia spp. Este es el primer estudio sobre la prevalencia de anticuerpos anti-cisticerco en una comunidad indígena del occidente venezolano, con un alto porcentaje de la prevalencia desde la infancia, sugiriendo una exposición temprana a la cisticercosis. Además, una alta prevalencia de protozoarios y helmintos intestinales, lo que supone un riesgo sanitario considerable en esta población.

To determine the presence of anti-cysticercus antibodies in an Amerindian community in western Venezuela, ninety-three individuals between 1-78 years of age were studied. Anti-cysticercus antibodies were detected using the ELISA immune-enzymatic technique with antigenic extracts of vesicular fluid of Taenia crassiceps. Sera were considered positive at 1:256 dilutions; feces were studied by direct and concentrate parasitological examination. A 27.9% of the population had anti-cysticercus immunity, and all age groups were positives. No statistically significant differences in relation to sex or between age groups were observed. In the physical examination and medical history, no data relevant to a probable functional impairment related to cysticercosis were found. The overall percentage of parasitic infection was 81.5%, with a marked polyparasitism of 64.6% and a predominance of protozoan infection. No Taenia spp eggs were detected. This is the first study on the prevalence of anti-cysticercus antibodies in an indigenous community of western Venezuela with a high percentage of prevalence from childhood, suggesting early exposure to cysticercosis. In addition, a high prevalence of intestinal protozoa and helminthes were found, which supposes a significant health risk in this population.

Detección de Entamoeba histolytica y Entamoeba dispar mediante PCR, en niños menores de cinco años con diarrea, en Maracaibo, Venezuela: Estudio preliminar / Detection of Entamoeba histolytica and Entamoeba dispar by PCR in children, less than five years of age with diarrhea, in Maracaibo, Venezuela: A preliminary study

Para determinar la prevalencia de Entamoeba histolytica como productora de diarrea, se realizó un estudio en niños menores de cinco años con diarrea que asistieron a diversas consultas del Servicio Autónomo Hospital Universitario de Maracaibo, Venezuela. A las muestras de heces obtenidas, se les realizó examen macroscópico, microscópico con solución salina fisiológica 0,85% y lugol, así como coloración de Kinyoun. El resto de la muestra se congeló hasta la extracción del ADN y luego se amplificaron mediante PCR separadas para E. histolytica y E. dispar. De las 50 muestras analizadas mediante examen microscópico, ninguna presentó trofozoítos y/o quistes de Entamoeba histolytica/dispar/moshkovskii, ni coccidios intestinales. Los parásitos detectados fueron Giardia lamblia (6%), Blastocystis sp. (6%), Pentatrichomonas hominis (2%), Ascaris lumbricoides (2%) y Trichuris trichiura (2%). Mediante PCR, 6 muestras (12%) presentaron ADN de E. dispar y 2 (4%) ADN de E. histolytica. Ningún niño presentó asociación de ambas amibas. Los dos niños que presentaron E. histolytica tenían 1 año de edad. E. dispar si fue detectada en niños de menor edad. Se sugiere que la prevalencia de E. histolytica en niños menores de cinco años con diarrea es realmente baja.

To determine the prevalence of Entamoeba histolytica as a producer of diarrhea, a study was conducted in children, less than five years of age, with diarrhea who attended several out patient clinics of the Servicio Autónomo Hospital Universitario, Maracaibo, Venezuela. A macroscopic and microscopic examination with physiological saline, lugol and Kinyoun staining were performed to the stool samples obtained. The remainder of the sample was frozen until DNA extraction, and PCR amplification was performed separately for E. histolytica and E. dispar. Microscopic examination showed no trophozoites and/or cysts of Entamoeba histolytica/dispar/moshkovskii, or intestinal coccidians in any of the 50 samples analyzed. Parasites detected were Giardia lamblia (6%), Blastocystis sp. (4%), Pentatrichomonas hominis (2%), Ascaris lumbricoides (2%) and Trichuris trichiura (2%). By PCR, six samples (12%) had DNA of E. dispar and two (4%) had DNA from E. histolytica; no child showed association of both amoebae. The two children who had E. histolytica were one-year-old. E. dispar was detected in younger children. We suggest that the prevalence of E. histolytica in children under five years is really low.

[Detection of Entamoeba histolytica and Entamoeba dispar by PCR in children, less than five years of age with diarrhea, in Maracaibo, Venezuela. A preliminary study]. / Detección de Entamoeba histolytica y Entamoeba dispar mediante PCR, en niños menores de cinco años con diarrea, en Maracaibo, Venezuela. Estudio preliminar.

To determine the prevalence of Entamoeba histolytica as a producer of diarrhea, a study was conducted in children, less than five years of age, with diarrhea who attended several out patient clinics of the Servicio Aut6nomo Hospital Universitario, Maracaibo, Venezuela. A macroscopic and microscopic examination with physiological saline, lugol and Kinyoun staining were performed to the stool samples obtained. The remainder of the sample was frozen until DNA extraction, and PCR amplification was performed separately for E. histolytica and E. dispar. Microscopic examination showed no trophozoites and/or cysts of Entamoeba histolytica/dispar/moshkovskii, or intestinal coccidians in any of the 50 samples analyzed. Parasites detected were Giardia lamblia (6%), Blastocystis sp. (4%), Pentatrichomonas hominis (2%), Ascaris lumbricoides (2%) and Trichuris trichiura (2%). By PCR, six samples (12%) had DNA of E. dispar and two (4%) had DNA from E. histolytica; no child showed association of both amoebae. The two children who had E. histolytica were one-year-old. E. dispar was detected in younger children. We suggest that the prevalence of E. histolytica in children under five years is really low.

Toxoplasma gondii infection lower anxiety as measured in the plus-maze and social interaction tests in rats A behavioral analysis.

It has been suggested that the parasite Toxoplasma gondii reduces the fear of rodents toward their feline predators, which may lead to an augmented rate of predation and multiplication of the parasite through an increased number of life cycles. To investigate whether T. gondii infection induces selective effects on behavior associated with anxiety, Wistar rats were inoculated i.p. with several doses of T. gondii tachyzoites and tested in two animal tests of anxiety. In the third week following inoculation, rats infected with 100 and 1000 tachyzoites increased plus-maze open arm exploration in a dose-related manner. However, no effect was detected in either social interaction levels or motor activity measures. In the seventh week after inoculation, rats infected with 100 and 1000 tachyzoites showed increased open arm exploration and social investigation without change on any motor activity measures. However, rats infected with a higher dose (1500 tachyzoites) showed a drop in locomotion. These data support the hypothesis that T. gondii impairs mechanism of warning as a function of reduced anxiety. The pattern of brain colonization by the parasite and the host immune response suggests that the predominant invasion to limbic areas works as a natural anxiolytic mechanism.

Respuesta inmunológica humoral en Uveítis: medición de anticuerpos contra el extracto crudo de retina bovina / Humoral immunological response in Uveitis: measurement of antibodies versus the bovine retinal crude extract

El extracto de retina bovina es una mezcla heteróloga de antígenos, de estos el antígeno soluble de la retina (Ag-S), es considerado el más inmunogénico. La respuesta humoral ha sido estudiada especialmente contra esta proteína y los reportes al respecto evidencian la existencia en el suero de anticuerpos anti-Ag-S, tanto en los individuos sanos como en los pacientes con uveítis, sin diferencias estadísticamente significativas. El objetivo de este estudio fue el de evaluar la respuesta humoral contra el extracto completo de retina bovina mediante una técnica inmunoenzimática (ELISA). Se logró evidenciar que las densidades ópticas obtenidas de los individuos con uveítis fueron superiores a los controles sanos con una diferencia significativa entre ambos grupos (p< 0,01), a pesar de esto la especificidad y sensibilidad de la prueba fue relativamente baja (57 por ciento y 86 por ciento respectivamente). Estos hallazgos difieren con lo reportado por Forrester y col. debido quizás a la presencia de anticuerpos contra otros antígenos de la retina distintos del Ag-S

Entamoeba histolytica: fecal antigen capture immunoassay for the diagnosis of enteric amebiasis by a monoclonal antibody

A amebiase mantem sua importancia epidemiologica em paises subdesenvolvidos onde sua prevalencia a converteu na parasitose de maior morbidade e mortalidade apos malaria e esquistossomose. Em regra, tanto o diagnostico clinico como os levantamentos epidemiologicos assentam na identificacao microscopica de cistos e/ou trofozoitos em extractos fecais. Este procedimento requer pessoal muito bem treinado, e laborioso, e frequentemente fornece resultados contraditorios. Para obviar estas dificuldades, no presente trabalho montamos uma tecnica de diagnostico imunoenzimatico baseado na captura de um antigeno de 96 kDa presente nas fezes de individuos infectados pela E. hystolytica (COPROELISA-Eh). Triplicatas de 117 amostras fecais processadas pelo metodo de concentracao formol eter foram definidas como positivas ou negativas por tres microscopistas especialistas em amebiase...