A serosurvey conducted across six slums in Mumbai's Cuffe Parade area has shown that 75 per cent of the residents tested positive for Covid antibodies, a sign of a past infection, which means either there is possibly a stigma associated with being diagnosed with Covid or people are scared of the consequences of being diagnosed with Covid, fearing social isolation or repercussions from the authorities.
As per reports from Mumbai Mirror, the serosurvey was conducted over six days, from October 5 to October 10, and involved 806 residents of the six slums — Machimar Nagar, the transit camp in Ambedkar Nagar, Ganesh Murthy Nagar Part 1, Ganesh Murthy Nagar Part 3, and Geeta Nagar. It was done at the request of local corporator Harshita Narwekar, who roped in Dr Nishant Kumar, an eye surgeon and founding trustee of the Eyebetes Foundation.
Out of the total 806 participants, 605 — or three out of every four — tested positive for Covid antibodies. The Eyebetes Foundation's report said this was one of the highest seroprevalence rates reported in India. Previous serosurveys in Mumbai's slums, conducted by the Brihanmumbai Municipal Corporation (BMC), found Covid antibodies in 54 per cent of residents (in August) and 45 per cent of residents (in October).
Posters were put up in the slums five days ahead of the survey and social workers visited people's homes to encourage them to participate. The findings bore out the residents' aversion to getting tested.
Social stigma more dangerous than Covid-19
According to the report, less than 1 per cent (8 of the 806) of respondents reported having been diagnosed with Covid-19 in the past. This means that either 99 per cent of them had an asymptomatic infection or that people were not willing to share information about a previous Covid infection.
In addition, 31 respondents (4 per cent) said they did not want to answer if they'd had a previous Covid infection or not, and only 15 (less than 2 per cent) said that someone in their family had been diagnosed with Covid-19 in the past.
"This data suggests that there is possibly a stigma associated with being diagnosed with Covid, and that people are reluctant to share this information even with healthcare professionals. The other possibility is that people are scared of the consequences of being diagnosed with Covid, fearing social isolation or repercussions from the authorities," Dr Kumar said.
He also said that the residents' general aversion to getting tested meant that there was some amount of selection bias, "but the fact is that we covered all five slums in that ward, and no matter what day or which slum we looked at the seroprevalence rate was always above 70 per cent".
Dr Kumar added, "The fear of being quarantined away from their families is probably the biggest disincentive for people to get tested. There needs to be a concerted effort to educate people about the need for RT-PCR testing, isolating and quarantining.
Unlike the BMC's sero surveys, which found that men were more likely to have been infected with Covid-19, this survey found that 79.3 per cent of the women (321 of 405) and only 70.8 per cent of the men (284 of 401) had been infected. "The higher prevalence of Covid among men in previous surveys was thought to be because men were more likely to go out for work, while women were more likely to remain at home. The higher prevalence rate among women in our survey could suggest that after the lockdown, women in slums may be congregating more, leading to an increased spread of infection," said Dr Kumar.
Avinash Supe, chairman of the state-appointed death audit committee, said, "Based on the 75 per cent prevalence rate I think we are close to herd immunity in slums in that area. Also, the fact that only 1 per cent had been diagnosed with Covid in the past tells us that most of the respondents had been asymptomatic or had only had mild symptoms but spread the disease to many others, including their families."
India's Covid-19 tally of cases climbed to 93.51 lakh on Saturday with 41,322 new infections being reported in a day. Around 87,59,969 people have recovered so far pushing the national recovery rate to 93.68 per cent, as per the latest health ministry data. Case fatality rate now stands at 1.46 per cent.