NEW DELHI: In states like Maharashtra, Tamil Nadu, and a few others, roughly 80% of the active Covid-19 cases are asymptomatic, according to data collated by TOI. However, seven large states – including Andhra Pradesh, Telangana and Punjab – and all of those in the North-east have recorded zero asymptomatic cases.
This suggests that numbers for the low-to-zero category may be grossly understated and makes comparison of number of cases in different states meaningless, say epidemiologists. If these states, where asymptomatic cases recorded were very few or zero, had the same proportion of asymptomatic cases as states like Maharashtra or TN, the total number of positive cases in the country could go up by over 6,000, taking the total to well over 21,000.
Then there are states like Delhi, Uttar Pradesh, Rajasthan and Madhya Pradesh, for which there was no data available on symptomatic and asymptomatic cases. If these too have primarily asymptomatic cases, the total number would get pushed even further up.
While the exact number may be a matter of debate, what the data indicates is that comparisons of numbers of cases across states could be misleading. “Its just not possible that in some states two-thirds to three-fourths of positive cases are asymptomatic, and in some others its zero. Theres a serious problem with recording,” said a public health expert.
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States that are following a wider testing protocol could be picking up many more cases and hence their numbers might seem larger relative to the others. This could also help explain the widely varying case fatality rates across states, an issue highlighted by TOI in an earlier report.
“Other states should be having a fair number of asymptomatic cases. It would be a fair conclusion that if they are not being picked up, the testing protocol is probably missing them,” said Prof Rakhal Gaitonde, a public health expert from the Sri Chitra Tirunal Institute for Medical Sciences and Technology in Thiruvananthapuram. “The wider the testing strategy, the higher the chance of picking up milder illness. But the issue also needs to be correlated with the proportion of tests being done per protocol and protocols in use may vary depending on thRead More – Source