Industry Odisha Bureau, July 31: India’s dengue burden is becoming more complex! A nationwide ICMR study reports that all four dengue virus serotypes are circulating simultaneously across eight states and Union Territories. Researchers say the findings are significant as India prepares to roll out its first indigenous dengue vaccine.
ICMR-National Institute of Virology (NIV), Pune conducted the study. It analysed 6,889 laboratory confirmed dengue samples collected through 45 Virus Research and Diagnostic Laboratories. Notably, the samples were collected across 25 States and Union Territories between 2023 and 2025.
The researchers also found that DENV-1, DENV-2, DENV-3, and DENV-4 are circulating together in multiple states. These include Andhra Pradesh, Gujarat, Haryana, Madhya Pradesh, Maharashtra, Rajasthan, Tamil Nadu, and West Bengal. Another 15 states and Union Territories reported three circulating serotypes, while the remaining two recorded two serotypes.
Further, the study also found that DENV-2 remained the dominant dengue strain. It accounted for 51% of infections. This was followed by DENV-3 (13%), DENV-1 (7%), and DENV-4 (1%). Around 7% of patients were infected with two or more serotypes simultaneously.
According to the researchers, infections involving multiple dengue strains were more likely to cause severe complications. The complications possibly being thrombocytopenia, haemorrhagic manifestations and joint pain.
The findings come as India prepares to introduce its forest indigenous dengue vaccine. Researchers said continuous molecular surveillance will play a key role in guiding vaccination strategies. This is since vaccine effectiveness may vary across different dengue serotypes. They also added that monitoring circulating strains will also strengthen outbreak forecasting and support public health planning.
