Chennai sero-survey has found that 21.5% of the city’s population has already been exposed to Covid-19 infection.
Blood samples of 12,405 people from 51 wards covering 15 zones were collected for this survey. (Representational image. Photo: PTI)
One in every five person living in Chennai is estimated to have had contracted Covid-19, a new population-based sero-survey for the transmission of coronavirus in Chennai has found.
The Chennai sero-survey was carried out as part of the national Covid sero survey. The survey found that overall one-fifth of Chennai’s population has already been exposed to Covid-19. In other words, around 80 per cent of the city’s population is still susceptible to Covid-19.
However, the survey also shows huge variation in sero-prevalence across different zones in the city, indicating different levels of transmission.
Blood samples of 12,405 people from 51 wards covering 15 zones were collected for this survey. Of these 12,405 samples, 2,673 people had evidence of past SARS CoV 2 infection, the survey found.
Sero survey involves testing of blood serum of people to check for the prevalence of antibodies against coronavirus infection.
Chennai is among the several cities in India where sero-surveys are being conducted to understand the extent of transmission of Covid-19 and what percentage of the population can be said to have developed antibodies against the viral infection.
Delhi was the first Indian city to conduct a sero-survey. It has already conducted several rounds of sero-survey and the lastest round started today and aims to cover a sample size of 17,000. The last sero-prevalence survey in Delhi was held from August 1-7, which showed that 29.1 per cent of the people surveyed had antibodies against the coronavirus infection.