The 2024 outbreak of Zika virus was limited to certain pockets in Erandwane, Mundhwa, Pashan, Warje and Yerawada in the city
Pune: High Aedes aegypti density and transmission-enhancing mutations in circulating Zika virus strains have left the city with a possibility of an increase in cases in future, a National Institute of Virology (NIV) study of Pune’s 2024 monsoon outbreak has warned. The study, recently published in Indian Journal of Medical Research, found that 26.5% of Aedes aegypti mosquito pools collected from neighbourhoods reporting cases tested positive for Zika RNA. The study was conducted between June and Sept 2024, when the city recorded 109 confirmed Zika cases.
Adult mosquitoes and larvae were collected from the houses of reported cases and surrounding premises within a 400m radius.
“These collections were done in the neighbourhood of positive cases and so the high positivity is limited to the neighbourhood and is not the virus positivity in the general mosquito population,” said Kavita Lole, one of the authors associated with the study. The study said the E-V473M mutation, found in the majority of current Zika virus strains in India, may have contributed to greater peripheral viraemia, efficient mosquito infection and viral spread. The researchers cautioned that the positivity rate was limited to outbreak-affected neighbourhoods and did not represent the general mosquito population of the city. Genomic analysis showed that the virus strains belonged to the Asian lineage and carried mutations that could favour transmission. Forty-five of them were pregnant women.