On Tuesday, the Union Health Ministry said according to Sero studies around a quarter of Delhi’s people have been infected by the coronavirus.
Dr Sujeet Kumar Sing, the director of the National Centre for Disease Control said that in Delhi around 23 per-cent people had built anti-bodies for the infection. However, he further added that 77 % are still exposed and the containment should be continued.
The NCDC along with the Delhi government tested 21,387 samples and the Sero study was conducted between June 27 to July 10. The Ministry stated that a large number of infected people are asymptomatic.
NCDC director Singh said, “When the prevalence was adjusted against the sensitivity and specificity of the ELISA test kits, the prevalence in Delhi was found to be 22.86 per cent and this is an adjusted figure… Eight of the total 11 districts have more than 20 per cent seroprevalence.”
Moreover, experts say that Delhi has not reached herd immunity. The CEO of The Welcome Trust/ DBT India Alliance said that for a population of 18.7 million, 23.5 % seroprevalence is seen which amounts to 4.4M infections.
With 3,663 deaths, the rate of infection is 0.08%, which is very similar to the first study done by seroprevalence in April.
Sing added that the above statement explains three things. First, the infection is spreading quite fast, second, since April there has been no mortality rate reduction, and finally the third is that we all are very far from the herd immunity.
“Delhi has so far done 8.3 lakh tests. If 20 per cent symptomatic of 4.4 million, there would be 8.8 lakh people with symptoms. But if only one positive is picked in 10 tests in Delhi, we are even missing symptomatic people and are definitely under testing even symptomatic,” he told PTI.
The Director of the Institute of Genomics and Integrative Biology, Anurag Agarwal said that as per survey around 25% of people have been infected by the virus and have recovered after settling for specificity and sensitivity.
He further said that some people may not have yet proper antibodies so the actual number may be 30 per-cent. He added that with this per-cent the transmission chains will be shorter.
Agarwal said that when serology positivity reaches 20 per-cent globally then the first peak happens.
He added that Delhi and Mumbai reached this point and Delhi already faced its first peak at the end of June.