68% confirmed cases, had no symptoms
Of the 885 infections reported, 601 people showed no visible signs
More than two-thirds of the Covid-19 cases reported in mainland China in the eight days until Tuesday were people who showed no symptoms of the disease, according to new figures released by the
National Health Commission (NHC)
While the ratio might appear high, the small data set meant it was too early to make any conclusions, according to Leo Poon Lit-man, head of the public health laboratory sciences division at the University of Hong Kong.
“We don’t know what these figures mean without having the same data [on asymptomatic patients] for the past three months,” he said.
“But what we do know, is that these asymptomatic patients could be pre-symptomatic and infectious despite not displaying symptoms.
“Therefore the virus is still being transmitted inside the country … and these patients should be treated in isolation and put under close observation.”
The NHC only began releasing the number of symptom-free cases last Wednesday, starting with figures for March 31 in a move it said was necessary to “address public concerns”.
Of the 885 cases reported in the eight-day period, 601, or 68 per cent, were asymptomatic, the NHC said. Of the 601, almost half – 279 – were reported in Hubei, the central China province at the heart of the initial coronavirus epidemic when it began at the end of last year.
Since the beginning of the outbreak in China, the total number of confirmed cases – all symptomatic – across the country was 82,000 as of Wednesday, with more than 3,300 deaths.
A total of 199 new cases were reported in mainland China on Tuesday, of which 137 were asymptomatic. Of those, 107 were imported cases, while 59 of the 62 symptomatic cases were also imported.
Poon said that widespread serological testing was necessary to determine the true proportion of asymptomatic patients. These tests look for antibodies in the blood, which usually develop within three to four weeks after infection.