A fifth of the population of Chennai has been exposed to Covid-19, a serological survey conducted in the capital city, has found, according to a report in the Hindustan Times. Chennai at present accounts for a third of the total cases in Tamil Nadu. A serological survey provides an understanding of the extent of the virus transmission. The Greater Chennai Corporation
tested 12,405 individuals of which 2,673 people or 21.5% were found to have developed antibodies to the virus. Around 80% of the population is still susceptible to Covid-19, the report stated.