Mumbai sero survey: 27 per cent health workers have developed COVID-19 antibodies

Mumbai: The first as well as the second round of sero-survey held in Mumbai have found that approximately 27 per cent health workers, who are more exposed to the virus than ordinary citizens, have developed antibodies against the infection.

The BMC had conducted the second round of sero-survey along with other organisations in the second half of August, while the first one was done in June. Civic officials said the sero-survey has important lessons for citizens, who are not following COVID-19 safety protocols of wearing face masks, maintaining social distance and hand hygiene.

“TIFR (Tata Institute of Fundamental Research (TIFR) has pointed out that health care workers have developed less antibodies though they are more exposed to the coronavirus. It is because they took adequate precautions like wearing masks and PPE kits, maintaining social distance and sanitising themselves properly,” Suresh Kakani, additional municipal commissioner of BMC said.

The presence of COVID-19 antibodies in samples from slums in the city was found to have decreased by 12 per cent in the second sero survey. It indicates that the infection spread in slums in the city may have come down

The latest survey disclosed that “sero-prevalence” of COVID-19 infection in slums is 45 per cent, compared to 57 per cent in the first sero-survey in the city (in July), the release said. The sero-prevalence in buildings was around 18 per cent against 16 per cent in the first survey, it added.

The latest survey was carried out in wards R-north (Borivali), M-West (Mankhurd and Govandi) and F-North (Worli and Lower Parel) in the second half of August.

The sero-prevalence of COVID-19 infection in women was marginally higher than men in both the rounds, it said. In the second survey, sero-prevalence in the age group above 40 was slightly higher. “Emerging scientific evidence hints at fall of antibody levels in recovered patients/asymptomatic patients over a period of time and this might have contributed to the trend between two rounds of sero-survey. "The impact of this on immunity, if any, is still unknown,” the release said.

Maharashtra on Friday recorded 15,591 new coronavirus cases, which took the total case count in the state to 14,16,513, the health department said. Out of the 15,591 new cases, 2,440 were recorded in Mumbai, taking the total number of recorded positive cases in the state capital to 2,10,060. With 424 COVID-19 patients succumbing, the death toll in the state due to the pandemic reached 37,480, while 42 new deaths in the city took its COVID-19 death toll to 9,014.