Molecular epidemiology of circulating dengue serotypes in Dhaka, Bangladesh: 2023 outbreak

Objectives

Dengue fever is a significant global health concern, especially in tropical regions, including Bangladesh, which reported 316,773 cases and 1652 deaths in 2023. This study intends to explore the circulating serotypes of the dengue virus (DENV) and their clinical associations across Bangladesh.

Methods

The study enrolled 1317 febrile patients presenting with at least two symptoms (nausea or vomiting, rash, aches and pains, positive tourniquet test, and leukopenia) at Dhaka Medical College and Hospital (DMCH) between July and August 2023. They provided demographic data, clinical features, and blood samples. DENV was tested using a rapid detection test and real-time reverse transcription-polymerase chain reaction.

Results

Of 1317 patients, 300 (23%) tested positive by rapid detection test and 775 (59%) by real-time reverse transcription-polymerase chain reaction. The median age of participants was 20 years, with 61% of confirmed cases being male. The DENV-2 serotype was found in 88%, DENV-3 in 12%, and only one was found positive for DENV-4. Overall, 80 percent of dengue-positive cases showed warning signs (abdominal tenderness, persistent vomiting, rash, and bleeding). The severity of cases was significantly higher with DENV-2.

Conclusions

This study generates insights into the distribution of dengue serotypes and their association with disease severity. The DENV-2 was found as the dominant serotype in the 2023 outbreak.