
A community-based sero-survey to estimate the prevalence of SARS-CoV-2 infection in Indian population will be started soon. The survey will be coordinated by the Indian Council of Medical Research (ICMR’s) National Institute of Epidemiology (NIE) and National Institute of Research in Tuberculosis (NIRT), Chennai.
The aim is to monitor the trend in prevalence of SARS-COV2 infection at the district level, Dr. Manoj Murhekar, director of ICMR-National Institute of Epidemiology (NIE), Chennai, told The Indian Express. This household-level cross-sectional survey will cover 24,000 adults distributed equally across four strata of districts categorised on the basis of reported cases of Covid-19. Overall, the survey will be conducted in randomly selected 69 districts from 21 states.
“There is a need to establish systematic surveillance for SARS-CoV-2 infection in all districts of the country. This surveillance will be in addition to the routine testing as per current testing guidelines,” said Dr. Murhekar.
The survey will involve collection of venous blood samples from 400 randomly-selected individuals (one per household) from 10 clusters in each district. Sera from these individuals will be tested for presence of IgG antibodies using ELISA test developed by ICMR-National Institute of Virology (NIV), Pune. The results of the survey will provide information about spread of SARS-CoV-2 infection in different parts of the country.
Besides this community-based survey, the Ministry of Health is also initiating hospital-based surveillance to monitor the trend of infection in all districts. Officials from the NIRT, which is the implementing agency, said that their trained staff will be sent to the sites to help with the survey.
From each district, 10 health facilities, including six public and for private health facilities, will be selected.
Throat/nasal swabs will be collected for RT-PCR tests. In addition to throat/nasal swabs, blood samples will be collected for detecting IgG antibodies for ELISA testing. According to state health officials, from Maharashtra, Beed, Nanded, Parbhani, Jalgaon, Ahmednagar and Sangli districts will be involved in the survey.