High prevalence of calcified silent neurocysticercosis in a rural village of Mexico.

Human neurocysticercosis (NC) is a parasitic disease caused by TAENIA SOLIUM when its larvae lodge in the central nervous system. NC prevalence estimates are obscured by the variable and often asymptomatic clinical picture. While infection depends on exposure, severity is possibly related with various host factors (immunity, genes and gender). This epidemiological study of cranial CT scans in an endemic rural community found that 9.1% of apparently healthy subjects had calcified lesions and were completely asymptomatic. Silent NC cases did not correlate with the exposure factors tested but showed family aggregation and higher rates of positive serology. Thus, NC prevalence may be higher than currently considered and host-related factors appear to be involved in infection and pathogenesis.