Co-circulation of three Dengue virus serotypes in 2017 in Dhaka city: First report from Bangladesh

Dengue is a major public health problem in Bangladesh similar to many other tropical regions of the world. There are four serotypes of dengue virus and circulation of all four serotypes were reported in our neighbor countries. Disease severity depends on serotype of dengue virus and serotype changes. So, serotype determination each year and observation of the change of serotype is important. However, yearly basis serotype data in Bangladesh is not available although dengue is endemic for more than decades. In an attempt to unveil the circulating serotype in Dhaka city, during July to December 2017, RNA from 181 reverse transcriptase PCR (RT-PCR) confirmed cases of dengue were screened for serotypes by serotype specific real time RT-PCR. DENV-1-3 were detected in 161 (88.95%) samples, of which 7 (4.34%) as DENV-1, 147 (91.3%) as DENV-2 and 7 (4.34%) as DENV-3 indicating DENV-2 was the predominant serotype of the outbreak. This is the first report of co-circulation of 3 dengue serotypes in a season in Dhaka city and warrants further surveillance of dengue serotypes for monitoring serotype changes and public health preparedness accordingly.