Mumbai, three districts in pan-India study to gauge community spread of Covid-19

MUMBAI: The city and three other districts in the state will be part of a pan-India seroprevalence study conducted by the Indian Council of Medical Research (ICMR) to gauge the community spread of Covid-19. Samples from 10 randomly selected households from seven city wards will be collected on April 29 and 30 in the first phase.


The study, across 85 districts from 25 states, will collect data from a mix of hotspots and less affected areas. Mumbai has been picked as a hotspot, while Beed, Parbhani and Nanded that have one positive case each, will represent less-affected regions.

Sources said the surveillance will be carried out using rapid testing for which the kits are likely to arrive in a day or two. In Mumbai, hotspots under wards G-South, G- North, E, F-North, F-South and B are likely to be the sample collection sites. Around 40 samples will be collected from one ward from people above 18 years.

“The results will have a bearing on the state’s decision on whether to continue with the lockdown, among other things,” said an official, adding that findings will also show if people have developed antibodies and present a picture of how big is the percentage of population that is exposed to the infection. The rapid testing kits will check for immunoglobulin M (IgM), the first antibody the body makes when it fights a new infection, and immunoglobulin G (IgG) that is found in the blood after repeated exposure. “While presence of IgM would mean the person has been recently infected, IgG would mean prolonged exposure,” said an expert.

BMC has said the second round of the study will be carried out 15 days after the first phase. The next lot of samples will be taken two months later. The first round of tests will be crucial as it will help decide the course of action. “Besides throwing light on community transmission, such a study can also tell us about asymptomatic patients,” said Dr Sujata Baweja, head of microbiology, Sion hospital.