Almost Quarter Of Delhi's Population Has Been Exposed To Coronavirus, Finds Sero-Prevalence Study

Sero-surveillance, generates important evidence for assessing the spread of the pandemic from time to time.

Commuters drive past a mural of frontline workers after the government eased a nationwide lockdown imposed as a preventive measure against Coronavirus in New Delhi. (Image: PTI)

New Delhi: The results and analysis of the serological survey conducted in Delhi has revealed that more than 23 per cent of national capital's population has developed IgG (Immunoglobulin G) antibodies, indicating they had been exposed to the novel Coronavirus. The study also indicates that a large number of infected persons remain asymptomatic.

A statement issued by the Ministry of Health and Family Welfare on Tuesday said that nearly six months into the epidemic and over 23.48 per cent 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 including prompt lockdown, effective containment and surveillance measures, including contact tracing and tracking, as well as citizen’s compliance to COVID-19 appropriate behaviours," the ministry said in a statement.

#IndiaFightsCorona:

The cross-sectional Sero-prevalence Study on #SARSCOV2 Infection finds a 22.86% prevalence of #COVID19 infection in Delhi. (the prevalence has been adjusted based on sensitivity and specificity of the Elisa test): @Director_NCDC #StaySafe #IndiaWillWin pic.twitter.com/vMqUpmVuEB — #IndiaFightsCorona (@COVIDNewsByMIB) July 21, 2020

It further added that a significant proportion of the population is still vulnerable. Therefore, the containment measures need to continue with the same rigour. "Non-pharmacological interventions such as physical distancing, use of face masks, face-cover, hand hygiene, cough etiquette and avoidance of crowded places etc., must be followed strictly," the statement read. The study was jointly conducted by the National Center for Disease Control (NCDC) and Government of National Capital Territory of Delhi following a rigorous multi-stage sampling study design. Teams were formed for all the 11 districts of Delhi and survey was conducted from June 27 to July 10. 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). 21,387 samples were collected as per lab standard sand were tested. The tests done help in identification of presence of antibodies in the general population. These test performed is not a diagnostic test but only provides information about past infection due to SARSCoV-2 in individuals who test positive. Antibody testing repeatedly done over time i.e. sero-surveillance, generates important evidence for assessing the spread of the pandemic from time to time.