One in 64 positive cases in China shows no symptoms of COVID-19

Fever, cough, shortness of breath — and pneumonia in severe cases — are some known symptoms of COVID-19. But one in every 64 persons tested positive in China is asymptomatic.

The country’s National Health Commission (NHC) on Wednesday (April 1) said 1,367 patients showed no symptoms and were under observation. Only the previous day, 130 new asymptomatic cases were added to the list. Such cases are excluded from the China’s official tally of confirmed cases, which stood at 81,554 on April 1.

Even English actor Idris Elba, in a Twitter video posted on April 1, said he was still asymptomatic, around two weeks after he had tested positive.

According to the World Health Organisation (WHO), the transmission from an asymptomatic person is very rare with other coronaviruses, including the Middle East Respiratory Syndrome (MERS) virus. So, it is likely not a major driver of transmission, WHO had said.

Recently, Chinese respiratory disease expert Zhong Nanshan too told the media that each asymptomatic person was potential of infecting 3 to 3.5 people and such patients would not cause a major outbreak if the chain of transmission is broken.

But with a large number of asymptomatic cases reported in China, India too needs to be cautious about this. In cases of foreign-returned, isolation of even an asymptomatic person who had come in contact with a suspected case is possible.

However, in case of clusters — a group in which infection spreads from the primary source to several or many others — identification of asymptomatic persons who had been infected with the virus will be an arduous task.