India's top health research agency on Tuesday revealed for the first time that of the total confirmed COVID-19 cases in the country 69 per cent patients have been found to be asymptomatic.
In effect, this means that nearly 7 out of 10 coronavirus patients could end up becoming silent spreaders of the infection if they are not quarantined in a facility.
Given that there are nearly 19,000 infected patients in the country, the estimation by the government suggests that about 13,000 of these people do not have any symptoms identified with the disease.
Dr RR Gangakhedkar, chief epidemiologist with the Indian Council of Medical Research, said during the daily briefing that "most of those without symptoms were those identified through contact tracing of the positive cases."
In India, the testing has been limited to those who have returned following international travel and have developed some symptoms, their close contacts, and healthcare workers treating confirmed COVID-19 cases.
The testing was later expanded to test all hospitalised patients with severe acute respiratory illnesses and influenza-like illnesses in hotspot areas.
Globally, it has been estimated that nearly 80 per cent of all COVID-19 patients have only mild or no symptoms and do not require hospitalisation.
Another 15 per cent are moderately sick, while only 5 per cent are likely to need ICU care. Nearly three per cent eventually succumb to the infection.
A large proportion of asymptomatic cases means that while not requiring hospital care themselves, these patients can still inadvertently spread the infection to several others -- some of whom may get severely ill.
Public health specialists meanwhile said that given that there is a big basket of symptoms related to COVID-19, apart from the classical symptoms of fever, dry cough and breathlessness, it's possible that some of them might not be documented due to lack of specific questioning of the patients.
"There are some lesser-known symptoms like gastrointestinal upset, lack of smell and headache etc that might be getting missed in rapid testing settings," said Dr Oommen John, public health researcher. "The presence of a large number of infected patients with no or very mild symptoms also underlines the need to create greater awareness for reporting such cases so that they can be isolated and the outbreak can be contained."