Prevalence and Risk Factors for Taenia Solium Taeniasis and Cysticercosis in Humans and Pigs in a Village in Morelos, Mexico

Abstract
In a Mexican village in which Taenia solium infection was known to be endemic, we selected a cluster sample of 368 households (21% of the total) for demographic, environmental, and diagnostic surveys, and medical histories for taeniasis and cysticercosis. Coproparasitologic studies of 1, 531 participants revealed infection by Taenia sp. in four (0.3%) individuals; however, 5.8% of the respondents reported a history of having passed tapeworm proglottids in feces. Of 1, 552 human serum specimens, 10.8% tested positive in the cysticercosis immunoblot assay. Seropositivity increased with age and reached a maximum in subjects ages 46–55 years. Risk factors associated with seropositivity included a history of passing tapeworm proglottids, frequent consumption of pork, and poor personal and household hygiene (P < 0.05). A history of seizures was also significantly associated with seropositivity (P < 0.05); approximately one-third of persons with such histories were seropositive. Of 571 pigs examined by tongue inspection, 23 (4.0%) had cysticerci; infection rates increased with the age of pigs, and were higher in pigs that habitually ran loose or were fed human feces (P < 0.05). Goodness of fit analysis confirmed that seropositive persons (but not infected pigs) were significantly clustered within households, particularly, in households in which a member reported a history of having passed tapeworm proglottids. The results of this study have identified community behavioral and environmental practices that must be modified to prevent continued transmission of cysticercosis and taeniasis.