Delhi govt plans more sero-surveys; next to be conducted from August 1-5

The Delhi government has decided to conduct sero-surveys every month to formulate better policies for tackling Covid-19 in the national capital, 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.

Interacting with reporters, he also said that the next survey will be conducted from August 1-5.

The minister reiterated that there is "transmission in the community" here and around 25 per cent of people have got infected and recovered in Delhi. But it is a technical term and only the Centre can take a decision to declare it, he said.

"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 anti-bodies, 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 sero-surveys every month 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.

Jain said the surveys will be conducted from 1st to 5th of every month and the Delhi government is working on making a detailed protocol for it, which will be conducted in both containment and non-containment zones.

The Delhi health minister said the survey will be based on a representative sample to understand the latest situation of the Covid-19 spread. Asked if herd immunity has been developed in the community, he said experts say that herd immunity is developed when 40-70 per cent of the population has recovered from Covid-19.

"We have received the results for about 24 cent of the population, and therefore, we cannot say, herd immunity has developed within the population in Delhi as per the results of the survey," Jain added.

The sero-prevalence 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.

Jain when asked the need for more such surveys, 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 anti-bodies, 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.

The minister said strategy is being made for the next survey, and more samples will be taken than in the previous exercise.

A sero-survey involves testing of blood serum of individuals to check for the prevalence of antibodies against infection.

"The population that was sampled was diversified, from young to old, man 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 1227 fresh coronavirus cases on Wednesday, taking the tally in the city to over 1.26 lakh,whilethe death toll from the disease rose to 3,719authorities said.

The total number of Covid-19 tests done till date in Delhi stands at 8,71,371.

The number of tests done per million to detect infection, as on Tuesday was 45,861 while the number of containment zones stood at 693. The minister also asserted that the percentage of deaths due to COVID-19 in July is "far less compared to what it was in June".

"There have been many interventions by the Delhi government, and I believe that these interventions have a huge role to play in reducing the fatality rate in Delhi. Earlier, there were complaints that people had to wait for a long time to get admission to the hospitals," Jain said.

"CM Arvind Kejriwal has directed that there should be a separate holding area in the hospital where the patients would be taken immediately and oxygen would be given. We have distributed 24,000 pulse oximeters which have also helped to reduce the number of deaths due to Covid," he said.