04-07-2025
Dengue's most dangerous serotype, DENV-2, circulating in Pune: Study
A major study being conducted in the city has revealed the presence of dengue virus serotype 2 (DENV-2), the variant that is most commonly linked with severe cases and hospitalisation. This serotype has been found in 65-70% of the samples tested in the city, with most of them belonging to Genotype II - Lineage F11. The finding has raised serious public health concerns, especially since the monsoon season is known to cause an upsurge in mosquito-borne illnesses. The dengue genome sequencing is part of this vertical programme with the Genomics Laboratory at BJMC leading the sequencing work. (REPRESENTATIVE PHOTO)
Titled, 'Prospective Observational Study to Map the Dengue Incidence in the Pune Municipal Region', the initiative started on March 24, 2023, through a collaboration between B.J. Medical College (BJMC), Pune, and Pune Knowledge Cluster Foundation.
The ongoing study started taking serum samples from April 2023 and has tested around 5,000 samples so far for dengue, using ELISA and rapid diagnostic methods. The data confirmed a sharp seasonal rise in cases during August to October in both 2023 and 2024, consistent with monsoon-related mosquito activity.
'Whole genome sequencing of dengue-positive samples was done to provide data that will help develop vaccines and low-cost molecular diagnostic assays for testing the disease,' BJMC officials said.
Dr Rajesh Karyakarte, Professor and Head, Microbiology, BJMC, said, 'We believe this study will contribute valuable data that can be useful in the development of vaccines and affordable molecular diagnostic tests.'
The Pune Knowledge Cluster (PKC) is using vector dynamics and viral epidemics to understand the prevalence of infectious diseases. The dengue genome sequencing is part of this vertical programme with the Genomics Laboratory at BJMC leading the sequencing work.
Dr Rashmita Das, assistant professor, Microbiology, BJMC, said, 'Preliminary findings reveal that Type 2 was the most frequently identified serotype, detected in approximately 65-70% of the sequenced samples. A small fraction of samples could not be definitively genotyped, indicating the potential presence of novel or divergent strains.'
Around 300 samples were tested using PCR to detect the viral genome, and 54 samples underwent whole genome sequencing. Shockingly, DENV-2 was found in 65-70% of the sequenced samples, most of them belonging to Genotype II - Lineage F11, followed by Genotype V. According to experts, DENV-2 is widely known to cause more severe disease, including dengue hemorrhagic fever and dengue shock DENV-3 serotype, like DENV-2, can also lead to severe forms of dengue. However, DENV-3 and DENV-4 were found in less than 5% of the sequences.
Dr Eknath Pawar, dean of BJMC and Sassoon General Hospital, said, 'The public health officials should intensify mosquito control measures, particularly in slum areas and construction sites. Citizens should get rid of stagnant water in their houses and surroundings, and use mosquito repellents. They should also avoid self-medication and seek medical attention promptly if symptoms such as high fever, body pain, and rashes appear. Treatment is available free of cost at Sassoon Hospital.'
Dengue is a vector-borne viral infection caused by the bite of an infected mosquito. It is caused by four different serotypes of the dengue virus - DENV 1, DENV 2, DENV 3, and DENV 4. Infection can occur due to any one or more than one of the four serotypes. These four serotypes are further subdivided into distinct genotypes.
