A fresh sero-survey will be conducted in the national capital from August 1-5 and such exercises will be conducted every month to formulate better policies for tackling COVID-19, Health Minister Satyendar Jain said on Wednesday.
The decision comes after the city government analysed the results of the latest sero-survey which showed that 23 per cent of the people here had exposure to the novel coronavirus.
The minister said a strategy is being made for the next survey, and more samples will be taken than in the previous exercise.
"The results of the sero-survey conducted from June 27-July 10 came out yesterday, and it shows that nearly one-fourth of people had developed antibodies, meaning they had got infected and recovered. Most of these people who were sampled did not know that they were infected earlier," Jain told reporters.
The Delhi government has now decided to conduct more monthly sero-surveys to find greater percentage of such people who had got infected and recovered, so as to formulate better policies for tackling COVID-19, he said.
On reports of some people trying to indulge in monetary transaction for convalescent plasma, Jain warned that "strict action" will be taken if anyone tries to buy or sell plasma.
On another query on whether compensation will be given to a doctor, who was working with Delhi government's National Health Mission and succumbed to COVID-19 recently, he said, it will be given.
The sero-prevalance study was done by the Delhi government in association with the National Centre for Disease Control (NCDC).
The study has found that around 23 per cent of the people surveyed in Delhi had an exposure to the novel coronavirus, the central government said on Tuesday.
According to Director of the NCDC, Dr Sujeet Kumar Singh, the remaining 77 per cent are still vulnerable to the viral disease and containment measures need to continue with the same rigour.
The study, conducted from June 27 to July 10 by the NCDC in collaboration with the Delhi government which involved testing 21,387 samples, also indicated that a large number of infected persons remain asymptomatic, according to the Union Health Ministry.
When asked about the need for more such surveys, Jain said, earlier a survey was undertaken in containment zones, then entire Delhi was represented with random sampling, and the results are coming out for the population sample which was infected 14 days ago or earlier.
"It takes 14 days to develop antibodies, so the result that has just come out, represents the situation of people who got infected, say around June 15 and recovered. The next survey will
represent the picture for later days," he added.
A sero-survey involves testing of blood serum of individuals to check for the prevalence of antibodies against infection.
For the survey, blood samples were collected from selected individuals after taking written informed consent and then tested for IgG antibodies and infection using COVID KAVACH ELISA approved by the Indian Council for Medical Research (ICMR). It was one of the largest sero-prevalence studies conducted in the country using the ELISA testing.
"The population that was sampled was diversified, from young to old, men and women, and across various areas, both with and without containment zones, and with successive surveys, the results will help us formulate better strategies. However, people must continue to practice safety norms, use masks, practice social distancing and wash hands regularly," Jain said.
Delhi recorded 1349 fresh coronavirus cases on Tuesday, taking the tally in the city to over 1.25 lakh,while the death toll from the disease mounted to 3,690, authorities said.
Officials said, all precautions will have to be taken by people to combat coronavirus, and government will continue with measures as "we can't let our guard down" even though comparatively less cases are being reported than couple of weeks before.
The total number of COVID-19 tests done till June 21 in Delhi stands at 8,51,331.
The number of tests done per million to detect infection, as on Tuesday was 44,805, while the number of containment zones stood at 689.
As per the latest survey, Southeast district of Delhi was found to have sero-prevalence of 22.12 per cent, Shahadara 27.61 per cent, Northwest 23.31 per cent, New Delhi 22.87 per cent, Central 27.86 per cent, Southwest 12.95 per cent, Northeast 27.7 per cent, East 23.9 per cent, North 25.26 per cent, South 18.61 per cent and West 19.13 per cent.