The Indian Council of Medical Research (ICMR) on Monday said that the majority of Covid-19 cases in the country could be without any symptoms.

"At least 80 out of every 100 Covid-19patients may be asymptomatic or could be showing mild symptoms. It takes a fewdays before an infected person begins to show symptoms and the probability ofbeing detected positive is highest when symptoms begin to show," said DrR. Gangakhedkar, senior scientist at ICMR, New Delhi.

"It is a new disease but we are doingeverything we can to combat it. As of now, we are not planning to change thetesting criteria," he said, when asked if this needed a change in testingstrategy to include those without symptoms. Contact tracing remains crucial.

It is difficult to detect asymptomatic cases and they canbe found out only after tracing the contacts of people who have been testedpositive, the top scientist said, adding that testing everyone is almostimpossible.