Dengue incidence
During the study period 58.2% (3401of 5842) of febrile children had acute samples collected (S1: 625 from IPD and 2776 from OPD) and 57.7% (3368 febrile children) had paired sera collected (S2: 625 from IPD and 2743 from OPD) and tested for DENV and JEV infection. There were 394 serological confirmed dengue cases (215 boys and 179 girls). The case number was lowest (51 cases) in 2006, then rose to 111 cases in 2007, reached a peak at 156 cases in 2008 and declined to 76 cases in 2009. Dengue occurred all year round but the highest number was from June to August in 2006, 2008 and 2009. In 2007 the disease was highest from June to December (figure 2). Dengue accounted for 2.73%, 7.78%, 10.18% and 7.50% of the febrile illness episodes in each of the study years, respectively and averaged 6.74% of the children with a febrile illness.