We evaluated the exposure of a community in Vellore district of south India to
Taenia solium infection and its relationship to the prevalence of
neurocysticercosis (NCC) causing active
epilepsy. Seroprevalence of Taenia cysticercus
antigens and
antibodies were determined in 1064 randomly chosen asymptomatic individuals,
antibodies to T. solium ova in 197 selected sera, and prevalence of
taeniasis by a coproantigen test in 729 stool samples. The prevalence of NCC causing active
epilepsy in Vellore district was determined in a population of 50 617. Coproantigens were detected in 0.8% (6 samples), Taenia cysticercus
antigens in 4.5% (48 sera) and cysticercus
IgG antibodies in 15.9% (169 sera) of the population. Cysticercus
antibodies were directed against relatively low molecular weight
cyst glycoprotein antigens in 14.9% (158 sera) of the population.
IgG antibodies to Taenia ova were found in 81 (41.1%) of the selected samples. Prevalence of NCC causing active
epilepsy was 1.3 per 1000 population. These results show high exposure of the population to the parasite and a relatively high prevalence of active
infections (4.5%
antigen positives) but a low prevalence of NCC causing active
epilepsy (0.13%). These findings may indicate that the population is protected against developing
neurocysticercosis.
IgG antibodies directed against Taenia ova and low molecular weight
cyst antigens may contribute to protection.