Nationally-representative serostudy of dengue in Bangladesh allows generalizable disease burden estimates.

Serostudies are needed to answer generalizable questions on disease risk. However, recruitment is usually biased by age or location. We present a nationally-representative study for dengue from 70 communities in Bangladesh. We collected data on risk factors, trapped mosquitoes and tested serum for IgG. Out of 5866 individuals, 24% had evidence of historic infection, ranging from 3% in the north to >80% in Dhaka. Being male (aOR:1.8, [95%CI:1.5-2.0]) and recent travel (aOR:1.3, [1.1-1.8]) were linked to seropositivity. We estimate that 40 million [34.3-47.2] people have been infected nationally, with 2.4 million ([1.3-4.5]) annual infections. Had we visited only 20 communities, seropositivity estimates would have ranged from 13% to 37%, highlighting the lack of representativeness generated by small numbers of communities. Our findings have implications for both the design of serosurveys and tackling dengue in Bangladesh.