Epidemiological study of Taenia solium taeniasis/cysticercosis in a rural village in Yucatan state, Mexico

A survey to detect human taeniasis and cysticcrcosis was conducted in a com munity in Yucatan state, Mexico, an area endemic for Taenia solium. Informa tion on the environmental, demographic and risk factors associated with tra nsmission of T. solium within the community was recorded on questionnaires. Although no Taenia eggs or proglottides were found in the initial faecal s amples collected from each of the 475 subjects, the results of a capture-EL ISA for T. solium coproantigen were positive for 10 of the subjects (of bot h genders and various ages). After treatment with niclosamide, proglottides were detected in purge samples from seven of these 10 subjects, The preval ence of parasitologically confirmed taeniasis was therefore 1.5% (seven in 475). The other three ELISA-positive cases delayed supplying faecal materia l post-treatment, and it is unclear whether they had expelled proglottides before providing the samples. All 10 ELISA-positive subjects became ELISA-n egative after treatment. Seroprevalence of human cysticercosis, based on the detection in immunoblot s of antibodies to antigens of 8- and 26-kDa from a crude saline extract of T. solium metacestodes, was 3.7% (i.e, five positives out of 134 subjects) . None of the seropositive cases demonstrated clinical symptoms of infectio n. Again, the positive cases were of both genders and various ages. Although tongue palpation indicated that 17 (23%) of 75 pigs kept within th e community had T. solium cysticercosis, the results of immunoblotting demo nstrated antibodies to the 8- and/or 26-kDa antigens of T. solium in 26 (35 %). The pigs allowed to roam throughout the community were far more likely to have cysticercosis than those kept in pens (odds ratio = 42, with a 95% confidence interval of 5.05-920.2; P < 0.00001). Not surprisingly, the risk factors associated with human taeniasis and cyst icercosis included the eating of infected pork and close proximity to a car rier of T. solium. The main risk factor identified for porcine cysticercosi s was free-range husbandry, permitting access to human faeces. This is the first comprehensive report of taeniasis and cysticercosis in a rural popula tion from the Yucatan peninsula of Mexico.