A novel low-cost approach to estimate the incidence of Japanese encephalitis in the catchment area of three hospitals in Bangladesh.

Acute meningoencephalitis syndrome surveillance was initiated in three medical college hospitals in Bangladesh in October 2007 to identify Japanese encephalitis (JE) cases. We estimated the population-based incidence of JE in the three hospitals' catchment areas by adjusting the hospital-based crude incidence of JE by the proportion of catchment area meningoencephalitis cases who were admitted to surveillance hospitals. Instead of a traditional house-to-house survey, which is expensive for a disease with low frequency, we attempted a novel approach to identify meningoencephalitis cases in the hospital catchment area through social networks among the community residents. The estimated JE incidence was 2.7/100,000 population in Rajshahi (95% confidence interval [CI] = 1.8-4.9), 1.4 in Khulna (95% CI = 0.9-4.1), and 0.6 in Chittagong (95% CI = 0.4-0.9). Bangladesh should consider a pilot project to introduce JE vaccine in high-incidence areas.