Mumbai, A Covid-19 sero-prevalence screening is currently underway for a group of doctors, nurses and frontline workers at the JJ Hospital, St Georges Hospital and GT Hospital in Mumbai, said Eyebetes Foundation, one of India's largest charitable initiatives for diabetes and blindness.

The Eyebetes Foundation collaborated with the JJ Group of Hospitals for the study, which began on June 23.

As part of the study, 200 doctors, 300 nurses and 300 frontline workers, including para-medical staff, cleaners, security personnel and administrative staff with patient contact, will undergo a simple blood test which will then be analysed for the presence of antibodies.

The study has been structured so that half the tests are conducted at JJ Hospital, which is a non-Covid hospital, and half the tests are conducted in dedicated covid hospitals such as St Georges Hospital and GT Hospital.

Establishing sero-prevalence, the proportion of people previously infected, is essential to understand the true spread of Covid-19 in the community and then plan strategies to prevent further spread and more importantly, to plan policies for relaxing lockdown and related restrictions in a planned and phased manner.

The Indian Council of Medical Research (ICMR) recently recommended the use of serological tests to evaluate the burden of the Covid infection in certain populations like frontline workers, nurses, doctors and other high-risk groups.

The blood test is not to diagnose an acute Covid-19 infection, but to evaluate past Covid-19 exposure.

"This is the largest study looking at sero-prevalence in one of the most vulnerable groups -- doctors, nurses and frontline workers working in Covid and non-Covid hospitals. Every study furthers our understanding of the disease," said Nishant Kumar, a Trustee of the Eyebetes Foundation.

This study will also evaluate if people with a previous infection with Covid-19 who have antibodies can yet test positive for the disease.

A subset of those with antibodies will also undergo a throat/nasal swab which will undergo the RT-PCR test to check if there is presence of Covid-19 virus, the Eyebetes Foundation said.