Estimates of Dengue Force of Infection in Children in Colombo,Sri Lanka

Dengue is the most important vector-borne viral disease worldwide and a major cause of childhood fever burden in sri lanka,which has experienced a number of large epidemics in the past decade. despite this,data on the burden and transmission of dengue virus in the indian subcontinent are lacking. as part of a longitudinal fever surveillance study,we conducted a dengue seroprevalence survey among children aged <12 years in colombo,sri lanka. we used a catalytic model to estimate the risk of primary infection among seronegative children. over 50% of children had igg antibodies to dengue virus and seroprevalence increased with age. the risk of primary infection was 14.1% per year (95% ci: 12.7%-15.6%),indicating that among initially seronegative children,approximately 1 in 7 experience their first infection within 12 months. there was weak evidence to suggest that the force of primary infection could be lower for children aged 6 years and above. we estimate that there are approximately 30 primary dengue infections among children <12 years in the community for every case notified to national surveillance,although this ratio is closer to 100:1 among infants. dengue represents a considerable infection burden among children in urban sri lanka,with levels of transmission comparable to those in the more established epidemics of southeast asia.