India had 6.4 million Covid cases by May: ICMR's sero survey
The findings of the first national serosurvey conducted by
the ICMR, published in the Indian Journal of Medical Research, indicated that
0.73 percent adults in India were exposed to SARS-CoV-2, amounting to a total
of 6.4 million infections by early May.
New Delhi :
The survey was conducted from May 11 to June 4 and covered 28,000 individuals whose blood samples were tested for IgG antibodies using COVID Kavach ELISA kit.
Also, seropositivity was the highest in the age group of 18-45 years (43.3 per cent), followed by those between 46-60 years (39.5 per cent) and it was the lowest among those aged above 60 (17.2 per cent).
A total of 64,68,388 adult infections were estimated in India by the early May, the survey report said.
"The findings of our survey indicated that the overall seroprevalence in India was low, with less than one per cent of the adult population exposed to SARS-CoV-2 by mid-May 2020.
"The low prevalence observed in most districts indicates that India is in early phase of the epidemic and the majority of the Indian population is still susceptible to SARS-CoV-2 infection," the survey report stressed.
According to the survey report, seroprevalence ranged between 0.62 and 1.03 per cent across the four strata of districts.
As part of the survey, a total of 30,283 households were visited from 700 clusters in 70 districts across the four strata. About one-fourth (25.9 per cent) of the surveyed clusters were from urban areas. A total of 28,000 individuals consented to participate, the report stated.
Nearly half (48.5 per cent) of the participants were aged between 18 and 45 and 51.5 per cent (14,390) were females. In all, 18.7 per cent of the participants had an occupation with a high risk of exposure to potentially infected persons.
The survey noted that there could be under-detection of COVID-19 cases in the zero stratum districts on account of low testing as well as poor access to testing laboratories.
The present findings of seropositivity in the strata of districts with zero to low incidence of COVID-19 cases underscores the need to strengthen surveillance and augment the testing of suspected cases in these areas, the survey report said.