Prevalence and Incidence of Epilepsy Associated with Convulsive Seizures in Rural Bolivia. A Global Campaign against Epilepsy Project

OBJECTIVE: we performed a three-stages door-to-door survey to estimate incidence and prevalence of epilepsy associated with convulsive seizures (EACS) in a rural area of Bolivia. METHODS: the study was carried out in the Cordillera Province, southern-eastern Bolivia. One hundred fourteen rural communities with a total population of 18,907 inhabitants were included in the survey. In order to identify subjects with EACS, trained fieldworkers administered a validated single screening question to the householders (stage I). A second face-to-face questionnaire was administered to each positive subject (stage II) that, in case of positive answer, underwent a complete neurological examination to confirm the diagnosis (stage III). We estimated age and sex specific life-time and active EACS prevalence at the prevalence day (30(th) June 2010). Incidence risk was evaluated for the 10-year period between January 2000 and December 2010. RESULTS: on prevalence day we identified 136 subjects with EACS, 124 of whom had active epilepsy. The life-time prevalence of EACS was 7.2/1,000 (7.6/1,000 age-adjusted to the world standard population) while the prevalence of active EACS was 6.6/1,000 (6.7/1,000 age-adjusted to the world standard population). Both life-time and active prevalence showed a peak (10.3/1,000) in the 15–24 years age group and, overall, were higher among women. During the incidence study period, 105 patients living in the study area had the onset of EACS. The crude incidence risk was 55.4/100,000 (49.5/100,000 age-adjusted to the world standard population). Incidence was slightly but not significantly higher among women (58.9/100,000 versus 51.9/100,000). CONCLUSIONS: the present study demonstrated a considerable burden of EACS in the Bolivian Chaco, showing prevalence and incidence estimates close to those reported for low and middle- income countries and underlying the need of treatment programs.