HYDERABAD: Dengue Virus-2 (DENV-2) caused nearly 60-65 per cent of dengue infections in Telangana between 2023 and 2025, while Dengue Virus-3 (DENV-3) accounted for the remaining 35-40 per cent, according to a nationwide molecular surveillance study published in the International Journal of Infectious Diseases.
Researchers found no cases of DENV-1 or DENV-4 at the Telangana study site during the three-year period.
Scientists from the Indian Council of Medical Research (
Revanth Reddy weighs Jayesh Ranjan, Vikas Raj for CS
Multiple infections raise risk of severe dengue
The study found that patients infected with more than one dengue virus strain faced a higher risk of severe illness. These patients were more likely to develop thrombocytopenia, haemorrhagic symptoms and arthralgia than those infected with a single strain.
About seven per cent of patients had infections caused by more than one dengue serotype. Around 21 per cent of the dengue-positive samples did not show a detectable serotype despite laboratory testing.
Across India, DENV-2 remained the most common strain. It accounted for 51 per cent (3,479) of the 6,889 samples analysed. DENV-3 accounted for 13 per cent, followed by DENV-1 at 7 per cent and DENV-4 at 1 per cent.
Continuous monitoring remains crucial
The researchers found that multiple dengue serotypes circulated in all 25 participating states and Union Territories.
Eight states and Union Territories reported all four dengue serotypes. Fifteen reported three serotypes, while two reported two serotypes.
Although DENV-2 remained the dominant strain across most regions, Tamil Nadu, Rajasthan and Haryana reported a higher share of DENV-1 infections. Uttar Pradesh, Tamil Nadu, Gujarat and West Bengal recorded higher circulation of DENV-3.
The researchers said continuous molecular surveillance is essential to track changes in circulating dengue virus strains. They added that regular monitoring can improve outbreak prediction and help guide future dengue vaccine strategies in India.