Only 28.3% of Delhi have been exposed to COVID-19, says latest serological prevalence survey

At least 28.3 %of people in Delhi have been exposed to COVID-19, according to the latest sero prevalence survey conducted in the capital. This means just a little more than a quarter of the population in Delhi have seroprevalence of antibodies against Sars-Cov-2 virus which causes the COVID-19 infection.

This is 5% more than that the serological survey done in early July, when Delhi showed only 23.48% prevalence. The survey was conducted in the first week of August in all the 11 districts and the sample size was 15,000. Two more rounds of sero survey are scheduled in the first weeks of September and October.

However, the percentage of prevalence could be higher as the August sample size was much lesser than the July sample size of 21,387.

Sero surveys are conducted to detect how many people have developed immunoglobulin (IgG) antibodies to coronavirus and to gauge the extent of infection through random sampling.These surveys help detect the exposure of the population to COVID-19. The blood samples are tested for antibodies and it helps identify those who may have had the disease without them realising it.

The findings of the survey show that women have higher prevalence of antibodies at 32.2%, while men have 28.3%. The seroprevalence of those younger than 18 was 34.7%, for those between 18-49 was 28.5% and for those older than 50, it was 31.2%.

According to the findings of the survey, Delhi’s South-East district had the maximum sero-prevalence at 33.2 %. This is a 50.09% increase in prevalence, when compared to the first sero survey. The lowest was at South-West district with 16.3; here too the percentage increase is 25.5.

After South-East district, North and Central districts had sero-prevalence of 31.6 and 31.4 respectively. Compared to the July sero survey, the districts showed a 24.98% and 12.6% increase respectively.

This is followed by Shahdara at 29.9 and this is an increase of 8.4% from the July survey. Then north-east district and north-west district at 29.6%, but the percentage increase of antibodies in those surveyed in the former district was 6.71, while in the latter, it was 26.98.

East district showed 28.9%, which is an increase of 25.4%; South district showed 27.2 prevalence, which is an increase of 46.21%; West district showed 26.5% prevalence, an increase of 38.6% and New Delhi showed 24.6%, which is an increase of only 7.7% compared to the July survey.

In the first serological survey conducted last month, 23.48% of Delhi’s population was found to have been exposed to Covid-19. It was based on 21,387 samples collected between June 27 and July 4.

The survey was conducted by the Delhi government with the support of Maulana Azad Medical College (MAMC) in New Delhi, which also manages Delhi’s first Covid-19 designated Lok Nayak Hospital.