1 in 5 persons developed antibodies in Delhi Covid-19 sero-survey: Report

The Supreme Health Services and Research Organisation of India located in Delhi that conducted a serological survey found that one in every five persons had the presence of antibodies, which indicated exposure to coronavirus.

The central government has said that there is a 22.86 percent positivity rate for the IgG antibodies. This indicates that the remaining, nearly 77 percent are vulnerable to the coronavirus, making it imperative to implement systematic safety measures and mark containment zones wherever necessary.

What is a serological survey?

In medical practice, a serological test is defined as a diagnostic method, which helps identify antibodies and antigens in the patient’s sample. In other words, the test identifies antibodies created in the immune system of a person who has recovered from a disease.

In the serological survey conducted in Delhi, a total of 21,387 samples was collected at random across 11 districts in the capital. These were then categorised into two groups, based on the person being above or below 18 years. The results of the survey were released on Tuesday.

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"The results of the sero-survey conducted from June 27-July 5 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," Health Minister Satyendar Jain said on Wednesday.

The study also indicates that a large number of infected persons remain asymptomatic, according to a Health Ministry statement. “Nearly six months into the epidemic, only 22.86 percent of the people are affected in Delhi, which has several pockets of dense population. This can be attributed to the proactive efforts taken by the Government to prevent the spread of infection…”

It was a collective decision executed by a high-level committee, headed by Dr V K Paul, head of the Health and Nutrition verticals at NITI Aayog, along with AIIMS Director Dr Randeep Guleria and NCDC and Delhi government experts to carry out this serological survey in the national capital.

Also read — Delhi govt plans more monthly sero-surveys, next to be done in August: Satyendar Jain

“Such scientific studies are extremely important and should be performed from time-to-time to understand the lessons from the past. The numbers collated are from the third week of June when the cases in Delhi were rising exponentially. It is important to note that when the survey was done the city was reporting over 3,000 cases a day. The robust data will be used well in the disease control programme,” Dr Paul told a news conference on Tuesday.

He added that the containment strategies adopted by the Ministry in coordination with NCDC and the Delhi government helped them prevent the further spread of the virus. "This shows that if scientific principles are followed well then a pandemic can be controlled well," Dr Paul added.

Also read — Covid-19: All you need to know about serological survey

The results of the Delhi sero-survey suggested a coronavirus prevalence of more than 20 percent in eight districts. The population in the Central, Northeast and Shahdara districts have been exposed to the virus to the largest extent, as they showed the highest coronavirus prevalence of over 27 percent.