A study by scientists of the Banaras Hindu University (BHU) has claimed that the actual number of Covid-19 cases in India, including unreported and asymptomatic, could be 17 times more than the official figure of 4.5 crore.
The study, which involved 88 scientists from 34 research institutes of the country, has been published in the prestigious science journal -- International Journal of Infectious Diseases (IJID).
It study was led by BHU geneticist Prof Gyaneshwer Chaubey of the department of Zoology, Institute of Science. The team of scientists conducted serosurvey (antibody testing) among 2,301 individuals in urban areas of 14 districts in six states from September-December 2020.
Prof Chaubey said that the most striking aspect of this study was that a large proportion of the Indian population was asymptomatic for Covid-19 and the age group 26-35 had the maximum number of asymptomatic people.
The researchers suggested that an antibody test in people after any Covid wave, accurately assesses the actual infection. Thus, adopting the same process, the team conducted this research among a large number of people (street vendors) living in urban areas from 14 Indian districts who were most at risk of coronavirus infection.
The samples were taken of only those who self-reported that they never had any Covid-19 symptoms or positive RT-PCR test. The minimum proportion of antibody-positive people was observed in Raipur, Chhattisgarh (2 per cent), while maximum proportion of antibody-positive persons was found in Ghazipur (47 per cent) in Uttar Pradesh.
The research suggests that the difference between the official numbers of infection and the actual possible infections, could be due to high number of asymptomatic cases which were never reported.
The study relied on mathematical modelling to arrive at assessment. Prof Chaubey said value should be viewed with caution, keeping in mind the limited geographical coverage of the study.