SHANGHAI • Scientists in China studying the coronavirus outbreak said they had found two main types of the virus could be causing infections.
The researchers, from Peking University's School of Life Sciences and the Institut Pasteur of Shanghai under the Chinese Academy of Sciences, cautioned that their analysis examined a limited range of data and said follow-up studies of larger data sets are needed to better understand the virus' evolution.
The preliminary study found that a more aggressive type of the new coronavirus associated with the outbreak in Wuhan accounted for about 70 per cent of analysed strains, while 30 per cent was linked to a less aggressive type.
They said the prevalence of the more aggressive virus decreased after early January. "These findings strongly support an urgent need for further, immediate, comprehensive studies that combine genomic data, epidemiological data and chart records of the clinical symptoms of patients with Covid-19."
Their findings were published on Tuesday in the National Science Review, the journal of the Chinese Academy of Sciences.
One of China's top medical associations yesterday confirmed that the median incubation period of the virus is five to seven days and the maximum 14 days. The remarks by Mr Du Bin, chairman of the critical care medical branch of the Chinese Medical Association, are the most conclusive assessment of the virus' incubation period by a government-affiliated medical body.
The revelations came amid a fall in new cases following crippling restrictions imposed on the world's second-largest economy to stop its spread.
China had 119 new confirmed cases of coronavirus on Tuesday, the National Health Commission said, down from 125 the previous day, in a broad trend that has seen numbers of new cases fall from the middle of last month.
The total number of cases on the mainland has now reached 80,270. The number of deaths rose by 38 to bring the total toll for China to 2,981 by Tuesday. All but one new death occurred in Hubei province, the epicentre of the outbreak.
REUTERS
