Serosurveillance to become a monthly affair in Delhi, say authorities

The state of Delhi, which houses the Indian capital, will be subject to a serosurveillance survey at the beginning of every month, according to the state's health minister Satyender Jain. Delhi has been one of the worth hit states in the country by the COVID-19 pandemic after Maharashtra and Tamil Nadu, with a total of more than 1.26 lakh cases in the state alone.

The health minister said that sampling would be carried out between the 1st and 5th of each month, to take stock of various aspects of COVID-19, such as infections, recoveries as well as to find out how many people have been infected by the disease but were cured due to the presence of antibodies. This is following the first Sero survey that was carried out in the month of June, and the following results produced some interesting data.

Blood samples from more than 21,000 people were taken in this survey conducted in collaboration with Delhi Government and the National Centre for Disease Control (NCDC). Investigations revealed that more than 23% of the people who were tested had antibodies for the coronavirus infection. However, most of them did not show symptoms of COVID-19, which means a large population of the state was asymptomatic.

At the same time, a large population still faces the threat of the virus, which is the reason why the Delhi government has now decided to conduct a Sero survey every month.

Serosurveillance is a large-scale programme to test the presence of antibodies against an infection that is causing an outbreak. It helps in identifying people or the size of the population that has developed antibodies to fight the virus, which can be used in the treatment of infected patients. Serosurveillance measures are particularly useful when there are no definitive treatments or vaccinations available to combat the disease outbreak.

Analysis of previous surveys have claimed that one out of every four or five people in Delhi has been infected by the SARS-CoV-2 virus that causes COVID-19, raising concerns in the Delhi state government. Significantly, a large part of Delhi's population lives in smaller areas, where the virus can rapidly spread and infect people.

NCDC Director Dr. Sujit Kumar Singh said that the remaining 77% of the population of Delhi was still at risk of COVID-19, thus the steps taken to control the virus need to continue.

Out of a total of 1,26,323 patients in Delhi, as many as 3,719 have died, but another 1,07,650 patients have also recovered at the same time. Statistics show that the death rate of COVID-19 in the capital is less than 3%, while the recovery rate has been over 85 percent. At the time of writing, about 11.84 percent of the infected - about 15,000 patients - are being treated.