Coronavirus | Sero-prevalence in T.N. stands at 23%

Survey was done before second wave

Prior to the second wave of the pandemic, around 23% of Tamil Nadu’s population, excluding Chennai’s, may have been exposed to SARS-CoV-2, the virus that causes COVID-19, according to the second sero-survey done by the Directorate of Public Health and Preventive Medicine during March-April. There was an overall reduction in the average antibody prevalence, compared with the first survey conducted during October-November 2020, when the State’s sero-prevalence was 31.6%. A total of 22,817 blood samples were collected from 45 health unit districts (HUDs), other than Chennai, for the second survey. Of the 22,721 samples processed, 5,242 returned positive, indicating a sero-prevalence of 23.1%. While the Poonamallee HUD recorded the highest sero-prevalence of 50.6%, Nagapattinam recorded the lowest of 8.9%.