Diagnosis of Taeniosis in rural Venezuelan communities: Preliminary characterization of a Taenia solium specific monoclonal (VP-1) Coproantigen ELISA.

The objective of this study was to identify and treat carriers of adult Taenia solium present in two rural Venezuelan communities through examination of faecal samples by coproscopical analysis, and by the application of a polyclonal and a monoclonal (VP-1) coproantigen ELISA. Both the polyclonal and monoclonal ELISA's were negative when tested with soluble extracts of adults of Ascaris lumbricoides, Hymenolepis nana and Trichuris trichura. The polyclonal ELISA was positive for soluble extracts adults of T. solium and T. saginata, whereas the monoclonal ELISA, which recognizes a glycoprotein, was restricted to T. solium, and was also negative with faecal samples from five cases of T. saginata adult infections. In the first community studied, Potrero Largo (Total population: 300), of 248 faecal samples examined, 2 individuals were positive for Taenia spp eggs by coproscopical analysis and the VP-1 ELISA, and yielded T. solium adults upon purging. In contrast, when the polyclonal coproAg ELISA was applied to the same 248 faecal samples, there were a considerable number of positives. Indeed, seven patients highly positive in the polyclonal ELISA did not yield a Taenia spp upon purging and were negative in the VP-1 ELISA. In the second community studied La Yuca (Total population 560), none of the 333 individuals who donated faeces was positive for Taenia spp eggs. Many, however, were infected with a range of intestinal helminth and protozoan parasites. A total of 76 faecal samples with representative intestinal parasite were then tested in the polyclonal and VP-1 assays. Of these, many gave an unacceptable number of significant optical densities in the polyclonal coproAg ELISA. In contrast, all were negative in the VP-1 ELISA, thus providing evidence for the species specificity of the VP-1 ELISA in faecal samples. These results with the VP-1 coproAg ELISA, although preliminary, justify further validation through the testing of more faecal samples from T. solium and T. saginata adult infected individuals.

Transmission of porcine cysticercosis in the Portuguesa state of Venezuela.

The aim of this study was to assess transmission of Taenia solium cysticercosis in Palmarito Arriba, a small village in the rural area of the Portuguesa state of Venezuela, through (1) an evaluation of T. solium transmission risk factors present in the community and (2) serological detection of the secreted metacestode HP10 antigen (HP10 Ag) and of anti-metacestode antibodies in sera from rural pigs. Risk factors associated with transmission of cysticercosis were the following: 100% (23/23) of the households lacked piped water, 87.0% (20/23) of households lacked latrines, 88.0% (100/114) of inhabitants routinely defecated in the open/air, 19.05% (12/63) of the interviewed population had observed proglottids in their stools. More significantly, 9/13 householders breeding pigs reported seeing proglottids in their stools. Of the 25 pigs available for bleeding and serological testing, 64% (16/25) were free roaming and 36% (9/25) were "backyard" animals; 28% (7/25) were seropositive for both the HP10 Ag and antibody, 20.0% (5/25) were seropositive for HP10 Ag alone, and 36.0% (9/25) were seropositive for antibody alone. Given this clear evidence of endemic porcine cysticercosis, further studies are needed to assess and control the level of porcine and human taeniasis and cysticercosis in this and neighboring communities.