29.1% of Delhiites exposed to COVID-19

About a third of Delhi’s population has been exposed to Covid-19 and has developed antibodies, the city government said on August 20, giving details of the second serological survey or serosurvey in the capital.

“29.1 per cent prevalence of the virus has been found in the second serosurvey,” Delhi Health Minister Satyendar Jain said. That meant 58 lakh people in Delhi now have antibodies.

The highest prevalence was found in the southeast district – 33.2 per cent – a massive spike from the previous survey (22.12). The least number of cases has been seen in the New Delhi area – 24.6 per cent.

“Scientists say that herd immunity is when up to 40 per cent of the population has virus antibodies,” Mr Jain said. According to him, those who had antibodies after being infected by the virus would be protected for six to eight more months.

“The antibodies will stay for six to eight months as per scientists,” said the minister, who was also hospitalised for COVID-19.

In the first serological survey last month, 23.48 per cent of Delhi’s population was found to have been exposed to the coronavirus.

A serological survey helps track the exposure of the population to a disease, which is particularly helpful when testing is comparatively low.
Blood samples are taken from respondents and these are tested for antibodies. Even people who were asymptomatic and may have recovered on their own can be detected. For this round, a sample size of 15,000 was taken from 11 districts.
The Delhi government announced last month that a serosurvey would be carried out in the beginning of every month.