Tamil Nadu has an overall seropositivity of 87% as per the phase-IV serosurvey conducted during the last week of December 2021. All 38 districts had a seroprevalence of over 80%, with Tiruvarur topping the list with 93% seropositivity.
The cross-sectional survey for SARS-CoV-2 infection transmission, which was taken up by the Directorate of Public Health and Preventive Medicine prior to the beginning of the Omicron-driven third wave in the country, covered 32,245 individuals aged above 10 years in 1,076 clusters across the State.
