Delhi Sero-Survey: Over 23% Residents Have Covid Antibodies

A medical health worker in Personal Protective Equipment collects a sample using a swab from a man in New Delhi on June 23, 2020

A Delhi sero-survey has reported that on an average, across Delhi, the prevalence of IgG antibodies is 23.48 per cent. The study conducted by the National Center for Disease Control (NCDC) also indicates that a large number of infected persons remain asymptomatic. The survey was conducted from June 27, 2020, to July 10, 2020.

A total of 21,387 samples were collected as per lab standards and were tested. The tests done help in identification of the presence of antibodies in the general population.

Antibody testing repeatedly done over time i.e. sero-surveillance, generates important evidence for assessing the spread of the pandemic from time to time.

How was Delhi sero-survey done?

For all the 11 districts of Delhi, survey teams were formed. Blood samples were collected from selected individuals after taking written informed consent and then their sera were tested for IgG antibodies and infection using COVID KAVACH ELISA approved by Indian Council for Medical Research (ICMR).

It is one of the largest sero-prevalence studies conducted in the country using the ELISA testing.

Results of Delhi sero-survey:

Notably, the study also indicates that a large number of infected persons remain asymptomatic. This implies the following:

1. Nearly six months into the epidemic, only 23.48 per cent of the people are affected in Delhi, which has several pockets of dense population.

2. However, a significant proportion of the population is still vulnerable. Therefore, containment measures need to continue with the same rigour. Physical distancing, use of face mask/cover, hand hygiene must be followed strictly.

Meanwhile, the total number of coronavirus cases in India has reached 11,55,191 , according to Union Health Ministry data. Delhi has 1,23,747 Covid-19 cases till date and is at number three after Maharashtra and Tamil Nadu.