Transmisión urbana de la enfermedad de Chagas en Caracas,Venezuela:: aspectos epidemiológicos, clínicos y de laboratorio

Classically, Chagas disease (ChD) is a rural disease with vectorial transmission. Oral transmission and the gradual increase of the finding of Panstrongylus geniculatus in Caracas, Venezuela, warrant an update of the epidemiological situation. Objective. To communicate the epidemiological, clinical and laboratorial diagnostic characteristics of Trypanosoma cruzi human transmission in Caracas. Materials and Methods. We selected cases of the Immunology Department at the Tropical Medicine Institute-Caracas studying also their contacts and inspecting the patient’s house. The laboratory diagnosis was based on parasite demonstration in blood and determination of specific antibodies by ELISA and indirect hemagglutination. Results. Between 1998 and 2007, ChD was diagnosed in 75 persons born and living in Caracas. Three infants with acute myocarditis and demonstration of chagasic infection died during that period. P. geniculatus was found in some patient’s houses. An outbreak of ChD in 103 persons, whose common risk was the ingestion of manually prepared juice in the morning snack, took place in an urban school. We explain the clinical characteristics of vectorial and oral cases in the city of Caracas and give particular diagnosis features. Conclusions. Although P. geniculatus is not an efficient vector, its coexistence with humans in Caracas is making food contamination possible and is forcing vectorial transmission. There must be an under recording of cases because the ChD screening is not done routinely. The demonstration of urban transmission of Trypanosoma cruzi should lead to modifications in the control strategy of ChD. Clásicamente, la Enfermedad de Chagas (ECh) es una patología rural y de transmisión vectorial. La transmisión oral y el progresivo incremento del hallazgo de Panstrongylus geniculatus en Caracas crean una nueva realidad epidemiológica. Objetivo. Comunicar las características epidemiológicas, clínicas y de diagnóstico de laboratorio de la transmisión humana del parásito Trypanosoma cruzi, en Caracas. Materiales y Métodos. Se seleccionaron pacientes que consultaron en la Sección de Inmunología del Instituto de Medicina Tropical, en Caracas; en algunos se estudió a los contactos y se inspeccionó la vivienda. El diagnóstico de laboratorio se basó en la demostración de parasitemia y en la determinación de anticuerpos específicos por ELISA y por hemaglutinación indirecta. Resultados. Entre 1998 y 2007 se diagnosticó ECh en 75 personas nacidas y res