Pan- India molecular surveillance of dengue serotypes, 2023-2025

Résumé fourni par la source

BACKGROUND: The four serotypes of dengue virus are a significant public health challenge in India, with regional variability in serotype circulation and limited comprehensive spacio-temporally harmonized data across diverse geographic areas. Thus, a nation-wide pan-India passive molecular surveillance study was conducted in 45 of 165 Virus Research and Diagnostic Laboratories (VRDLs), in 25 states and union territories between 2023 and 2025. METHODS: A total of 6889 dengue positive serum samples referred to the VRDLs (n = 45) for diagnosis of dengue were tested by Realtime reverse transcriptase PCR for determination of infecting serotypes. RESULTS: All regions showed co-circulation of multiple serotypes, with eight states having all four serotypes co-circulating. DENV-2 was predominant during the study period. Increased likelihood of thrombocytopenia, arthralgia, and hemorrhagic manifestations were directly associated with concurrent infections with multiple serotypes compared to mono-serotypic infections. CONCLUSION: These findings underscore the importance of continuous, geographically representative molecular surveillance to monitor evolving dengue serotype dynamics, informing outbreak prediction and guiding dengue vaccine introduction strategies in India.