NEW DELHI: Nearly 14 per cent of the total confirmed Covid-19 cases in India till April had no history of exposure to any known cases of infection and more than 44 per cent did not have documented history of exposure, a report by the Indian Council of Medical Research has shown.
The report published in the Council’s Indian Journal of Medical Research has revealed that of 40, 184 Covid-19 patients in India till April end 5, 403 hospitalised were either Severe Acute Respiratory Illness patients or those with influenza like symptoms in hotspot areas, in other words cases due to community transmission of the disease.
The same report, based on 1,021, 518 samples tested till April 30, also mentioned that contact history of 44.2 per cent or 17,759 of total positive cases who had tested positive for the infection were not specified.
The findings are part of the report “Laboratory surveillance for SARS-CoV-2 in India: Performance of testing & descriptive epidemiology of detected Covid-19, January 22-April 30” prepared by the epidemiologists at the ICMR along with researchers from the WHO, Public Health Foundation of India and some independent health researchers.
The report also showed that over 25 per cent of all confirmed cases were asymptomatic high risk contacts of confirmed cases, while 10.6 were those high risk contacts who had developed symptoms at the time of testing.
Also, more than 5 per cent of confirmed cases were healthcare workers — either those who had developed symptoms or those asymptomatic who had come into contact with confirmed cases without adequate protection.
The study threw a puzzling number of 17,759 confirmed cases who did not fall into any of the categories for which testing is permitted.
An epidemiologist associated with the report said that this could be a result of either poor record keeping by states or data entry problems.
“In studies like this one where programmer data is used, it is a limitation—because collecting the data is not in our hands,” he said.
“These could either be cases of community transmission, from a cluster in case extensive testing was done or simply data error--but we cannot tell for sure.”
Meanwhile, scientists also analysed that positivity rate, at over 10 per cent, is the highest across all categories among the symptomatic contacts of cases.