ABSTRACT
An epidemiological survey of Trypanosoma cruzi infection was carried out in Bodocó, located in the western part of the State of Pernambuco, Brazil. Two hundred and forty-one individuals were parasitologically and immunologically screened. Although hemoculture did not reveal the presence of parasites in the blood, the sera of 5 individuals were scored as positive by the indirect fluorescence antibody test and the enzyme-linked immunosorbent assay. Seropositivity in individuals above and below the age of 40 was 14.8 and 0.5%, respectively. These results indicate that recent infections with T. cruzi are rare in this area. However, since a T. cruzi-infected triatomid (Triatoma brasiliensis) was captured in a school classroom, this area must be considered endemic. When triatomid feces containing parasites were inoculated into a jird (mongolian gerbil), parasitemia appeared 10 days later. Immunohistochemical staining, using monoclonal antibody specific for T. cruzi, labeled organisms in jird tissues. These observations demonstrate that the jird is a suitable host for experimental T. cruzi infections and that monoclonal antibody is effective for detection of the parasite in host tissues.
Subject(s)
Chagas Disease/epidemiology , Adult , Animals , Antibodies, Protozoan/blood , Brazil/epidemiology , Chagas Disease/immunology , Chagas Disease/parasitology , Child , Humans , Insect Vectors/parasitology , Panstrongylus/parasitology , Population Surveillance , Triatoma/parasitology , Trypanosoma cruzi/immunology , Trypanosoma cruzi/isolation & purificationSubject(s)
Antibodies, Protozoan/blood , Blood Donors , Chagas Disease/epidemiology , Trypanosoma cruzi/immunology , Adolescent , Adult , Animals , Bolivia/epidemiology , Humans , Middle Aged , PrevalenceABSTRACT
The pathogenicity of 47 strains of Entamoeba histolytica isolated in Pernambuco, Brazil, was examined using the polymerase chain reaction (PCR) followed by restriction-endonuclease digestion. Electrophoretic patterns of PCR products digested with HinfI revealed that all strains were nonpathogenic. The results were entirely in accord with phenotypic properties such as isoenzyme patterns and the failure to bind a pathogenic-isolate-specific monoclonal antibody. When the sensitivity of PCR was examined, amplified products could be detected from template DNA equivalent to five trophozoites. These observations indicate that PCR amplification of genomic DNA and subsequent restriction-enzyme digestion is a useful strategy for obtaining a sensitive and accurate diagnosis. The present study also demonstrates that nonpathogenic strains of E. histolytica predominate in northeastern Brazil.
