New Delhi:

Nearly a third of Delhi’s population has been exposed to Covid-19 and so has antibodies to fight it, the city government said today, giving details of the second serological survey or serosurvey in the capital.

“29.1 percent 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.

The first survey was carried out in the first week of August. In the first serological survey, 23.48 per cent of Delhi’s population was found to have been exposed to the coronavirus.

The other two rounds are scheduled in the first weeks of September and October.

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.