Neurocysticercosis: a major aetiological factor of late-onset epilepsy in Madagascar.

To assess the impact of cysticercosis on public health in Madagascar, we compared patients > 15 years with late-onset epilepsy to non-epileptic controls in a matched case-control study. The association between epilepsy and cysticercosis was studied by enzyme-linked immunoelectrotransfer blot (EITB) assay for antibodies specific to Taenia solium. The EITB assay was performed on 104 pairs of sera specimens and on 95 pairs of cerebrospinal fluid (CSF) specimens. Depending on whether we consider the results obtained from sera or from CSF, we obtain for the population attributable risk percent of cysticercosis in late-onset epilepsy two slightly different estimates: 22.3% and 17.6%. Therefore cysticercosis is a major aetiological factor of late-onset epilepsy in Madagascar. In the control group, the frequency of positive results, especially in CSF specimens (7.4%), confirms the existence of asymptomatic cases of neurocysticercosis.