ABSTRACT
Trypanosoma cruzi I, a discrete typing unit (DTU) found in human infections in Venezuela and other countries of the northern region of South America and in Central America, has been recently classified into five intra-DTU genotypes (Ia, Ib, Ic, Id, Ie) based on sequence polymorphisms found in the spliced leader intergenic region. In this paper we report the genotype identification of T. cruzi human isolates from one outbreak of acute orally acquired Chagas disease that occurred in a non-endemic region of Venezuela and from T. cruzi triatomine and rat isolates captured at a guava juice preparation site which was identified as the presumptive source of infection. The genotyping of all these isolates as TcId supports the view of a common source of infection in this oral Chagas disease outbreak through the ingestion of guava juice. Implications for clinical manifestations and dynamics of transmission cycles are discussed.
Subject(s)
Chagas Disease/epidemiology , Chagas Disease/parasitology , Disease Outbreaks , Genes, Protozoan , Trypanosoma cruzi/genetics , Animals , Base Sequence , Beverages/parasitology , Chagas Disease/transmission , Genotype , Genotyping Techniques , Humans , Molecular Sequence Data , Psidium , Rats/parasitology , Schools , Sequence Alignment , Trypanosoma cruzi/classification , Trypanosoma cruzi/isolation & purification , Venezuela/epidemiologyABSTRACT
This study examined the seroprevalence and serum antibody isotype profile for Taenia solium cysticercosis in an Amerindian community in the Amazonas state of Venezuela. An antigen-trapping enzyme-linked immunosorbent assay (Ag-ELISA) was used to detect viable cysticercosis. Indirect ELISA (Ab-ELISA) and enzyme-linked immunoelectrotransfer blot (EITB) was performed by using antigens prepared from T. solium metacestodes to detect anti-parasite antibodies. The Ag-ELISA and Ab-ELISAs revealed 64.7% and 79.0% seropositivity, respectively, in the Amerindian population. Immunoglobulin (Ig) M was the predominant antibody class, suggesting recent infection. In comparison sera from, clinically defined, hospital neurocysticercosis cases revealed only 27% seropositivity by Ag-ELISA, compared with 86-92% seropositivity by Ab-ELISA, and IgG4 was the predominant antibody subclass detected. The EITB antigen recognition patterns of the hospitalized patients were very similar to that of the Amerindians, confirming exposure to the parasite. These results, combined with the predominance of IgM antibody responses and the marked detection of secreted products of viable parasites, strongly suggest that recent exposure to T. solium had occurred in the Amerindian population.
