NEW DELHI: The government on Thursday said that the findings of the first serosurvey conducted to gauge the extent COVID-19 virus spread in the general population have revealed that less than 1 per cent of the population in non-hotspot districts has been infected with the pathogen so far.
In a press conference on outbreak management in the country, Indian Council of Medical Research Director-General Dr Balram Bhargava said that the first part of the survey through which samples collected from 83 districts were analysed showed that overall 0.73 per cent of the population in these districts had antibodies against SARS CoV 2.
These districts were spread across 21 states and were categorised on the basis of zero, low, medium and high caseloads and a total of over 26,000 randomly selected blood serum samples were tested using ELISA antibody testing kit developed by the National Institute of Virology, Pune.
“That means that large chunk of population in the country is still very susceptible to the infection,” said Dr Bhargava while maintaining that there is no community transmission of the virus in India yet.
"The prevalence has been found to be less than 1 per cent in small districts. In urban and containment areas it may be slightly higher. But, India is definitely not in community transmission. I would like to emphasize it," he said.
The exercise carried out in collaboration with the National Centre for Disease Control, state health departments and WHO India had two parts - to estimate the fraction of population infected with SARS CoV-2 in the general population and also assess the number of total infected in containment zones of hotspot cities.
While the study of infection in the general population is complete, the data from containment zones in 10 hotspot cities that include Delhi, Mumbai, Chennai, Ahmadabad, Indore and Pune among others is still being analysed.
The ICMR has now estimated that the fatality rate due to the infection is very low at 0.08 %.
Experts, meanwhile, based on the infection prevalence and infection fatality rate, estimated that the present infection in the country could be as high as 2 crores as against the official figure of 2.86 lakh.
“Based on what the survey has shown, total infections in the third week of May could be 1 crore plus,” said virologist Dr Shahid Jameel, who is CEO of the Wellcome Trust DBT India Alliance. “But these total infections were 18 days back since on average it takes 18 days from infection to death. Considering the doubling rate of 16-20 days, the total infections today could be 2 crores.”
Public health researcher Oommen C Kurian, on the other hand, estimated the present infection size in the country to be as big as 5 crores.
Sharing the analysis of data collected through the survey, officials meanwhile also said that the risk of people contracting the virus in urban slums was 1.89 times higher than the rural areas, while the risk in other urban areas was 1.09 times higher compared to rural areas.
Dr V K Paul, chairman of the national task force on COVID-19 called the survey the biggest such surveillance exercise in the world.
Key findings of the ICMR’s serosurvey from non-hotspot districts
- 0.73% of the population in districts from where samples were collected had evidence of past exposure to the virus
- Large population is susceptible and is vulnerable to the virus
- Risk of infection is higher in urban areas by 1.09 times as that of rural areas. In urban slums, the risk of infection is 1.89 times higher than rural areas.
- Infection fatality rate is very low at 0.08%
- Infection in containment zones found is way high with significant variations (ongoing study)