Dengue virus (DENV) serotypes (Health, Diseases and Biotechnology)
Dengue virus (DENV) serotypes (Health, Diseases and Biotechnology)
Why In News:
A new molecular surveillance study has found that multiple dengue virus (DENV) serotypes are co-circulating in parts of India, a pattern associated with a higher risk of severe dengue and complicating both diagnosis and vaccine strategy.
Source: The Hindu, Page 12, 29 July 2026 - 'Study finds multiple dengue virus strains circulating together in India'
About Dengue
Dengue is caused by the dengue virus (DENV), of which there are four distinct serotypes: DENV-1, DENV-2, DENV-3, and DENV-4.
Dengue is transmitted by the bite of the female Aedes aegypti mosquito (and, to a lesser extent, Aedes albopictus), which breeds in clean, stagnant water.
Infection with one serotype confers lifelong immunity to that serotype only; a subsequent infection with a different serotype carries a much higher risk of severe dengue (dengue haemorrhagic fever/dengue shock syndrome) due to a phenomenon called Antibody-Dependent Enhancement (ADE).
Co-circulation of multiple serotypes in the same region increases the probability of sequential heterotypic infections in the population, raising overall disease severity.
India remains a hyperendemic country for dengue, with recent surveillance studies showing DENV-2 as the most frequently detected serotype in several states, alongside DENV-1 and DENV-3.
There is currently no universally approved dengue vaccine for India; global vaccines such as Dengvaxia are restricted to those with prior confirmed dengue infection due to ADE-related risk in dengue-naive individuals.
Key Facts for Prelims
Warning signs of severe dengue include persistent vomiting, abdominal pain, bleeding, and a sudden drop in platelet count, typically appearing after the fever subsides (the 'critical phase').
ICMR's National Institute of Virology (NIV), Pune, and its network of Viral Research and Diagnostic Laboratories (VRDLs) play a key role in serotype surveillance across India.