Taenia solium taeniasis and cysticercosis in a Mexican village.

One hundred and twenty-four persons, nearly the entire population of a rural village in Hidalgo State, were screened for intestinal parasites and clinical or serologic (ELISA) evidence of Taenia solium cysticercosis. Heads of households were questioned about dietary and other practices that might lead to pork tapeworm transmission, and soil samples were examined for helminth eggs. Twenty-five percent of local pigs had cysticerci visible by examination of the undersurface of their tongues. Four persons passed taeniid eggs, 7 were seropositive, and 10 gave medical histories suggestive of neurodysticercosis. Most seropositive persons were not symptomatic and the reverse was also true. The clustered distribution of infected pigs, tapeworm carriers, and persons with serologic or clinical evidence of cysticercosis suggested intrahousehold transmission. Dietary and sanitary practices were generally optimal for transmission of pork tapeworm. No cattle were kept in the village and beef was rarely eaten. This preliminary report attempts to characterize T. solium transmission in communities with endemic disease in rural Mexico and illustrates some of the methodological problems faced by epidemiologists who study this disease.