Mumbai’s 21-40 age group most exposed to Covid-19 antibodies: Private lab
A sero-survey by a private laboratory in the city has found that those between 21 to 40 registered the highest positivity rate of antibodies. Metropolis Laboratory conducted a sero-survey based on samples collected between June and August. The high positivity rate suggests those in the age group of 21-40 comprise the majority of those who have recovered from Covid-19 in Mumbai. Metropolis’s data also suggests more women in the 21-30 age group contracted Covid-19 and men aged between 31-40 were most affected by the infection.
For its sero-survey, Metropolis studied 16,697 random samples collected between June 26 and August 17. Of these, 11,623 samples were from men and 5,074 were from women. The overall positivity rate for antibodies was 33%. These recovered people are now potential donors of plasma as studies suggest antibodies decay after three to four months.
The sero-survey also noted differences in positivity rates between age groups and genders. While 31.8% of the samples from men aged between 31-40 tested positive for antibodies, the percentage dipped to 23.9% for those aged between 21 to 30. Those between 41-50 years and 51-60 years recorded 21.4% and 11.6% positivity rates respectively.
Of the samples collected from women, those between 21-30 years recorded a positivity rate of 27.4%, followed by 23.2% for those aged between 31 to 40 years. Those between 41-50 years recorded 19.2% positivity while those in the 51 to 60 age group recorded 13.3%.
The survey also found some samples did not test positive for antibodies despite having tested positive for Covid-19. Dr Nilesh Shah of Metropolis Laboratory said, “The data indicates that immunity for everybody is different as 20% of the 167 samples who had previous history of Covid-19 tested negative for Covid-19 antibodies. Also, in case of age wise data, the positivity rate is higher in the younger age group because they probably have more exposure outside when compared to the older age group.”
Subhasree Ray, clinical nutritionist and public health professional, also said men and women in 21-40 years’ age group are likely to be the most exposed to the infection.
Geographically, the highest positivity rates in the city were in Parel (44%), Borivli (W; 39%), Sion (39%), Saki Naka (38%), Khar (38%), Mulund (37%), Malabar Hill (35%) and Worli (33%).The lowest positivity rates were in Kandivli (19%), JB Nagar (18%), IIT-Bombay (17%), Grant Road (17%) and Churchgate (17%).
A survey carried out in the city by private laboratory Thyrocare, using 8,376 samples collected between July 3 and August 7, found a positivity rate of 28.89% . High positivity rates were recorded in areas that were Covid hotspots, including Govandi (57%), Dharavi (54%), Worli (42%), Chembur Extension (48%) and Mazgaon (40%).
The results of the second phase of Brihanmumbai Municipal Corporation’s (BMC) sero-surveillance, which is being carried out in three wards, is expected this week. The first phase found 57% from slums and 16% from other residential areas had been exposed to Covid-19.