BEIJING • China believes a mysterious pneumonia outbreak that has struck 59 people is caused by a new strain of virus from the same family as the deadly Sars bug.
Lead scientist Xu Jianguo said experts believe that a new type of coronavirus caused the outbreak last month in Wuhan, a central Chinese city with a population of more than 11 million.
It initially sparked fears of a resurgence of the highly contagious severe acute respiratory syndrome (Sars), and prompted the authorities in Hong Kong to take precautions, including stepping up the disinfection of trains and air-planes, and checks on passengers. Singapore also conducted temperature screenings of air passengers from Wuhan.
China has since ruled out a fresh outbreak of Sars, which killed 349 people there and another 299 in Hong Kong in 2003.
A total of 15 positive results of the new type of coronavirus had been detected in the lab, through tests on infected blood samples and throat swabs, said Mr Xu.
The World Health Organisation (WHO) confirmed in a statement the preliminary discovery of a new coronavirus.
"Further investigations are also required to determine the source, modes of transmission, extent of infection and countermeasures implemented," said Dr Gauden Galea, the WHO representative to China.
Coronaviruses are a large family of viruses that can cause infections, ranging from the common cold to Sars. Some of the virus types cause less severe diseases, while others - like the one that causes the Middle East respiratory syndrome (Mers) - are more lethal. WHO noted that coronaviruses emerge periodically - including in 2002 to cause Sars, and in 2012 to cause Mers.
It said that according to the Chinese authorities, the virus behind the Wuhan cases can cause severe illness in some patients and does not appear to pass easily from person to person.
So far, of the 59 patients, only seven have been seriously ill. Eight have recovered and were discharged from hospital on Wednesday.
The Wuhan health commission said the infection broke out between Dec 12 and 29, and some of the patients were workers at a seafood market which has since been closed for disinfection.
The outbreak comes just a few weeks before China's busiest annual travel period, when millions of people take buses, trains and planes home for the Chinese New Year.
A Chinese Transport Ministry official said arrangements were put in place to disinfect and monitor all stations and cargo hubs.
In Hong Kong, hospitals have raised their alert level to "serious" and temperature checks are in place at borders for inbound travellers.
The authorities said 38 people have been hospitalised in recent days after returning from Wuhan with flu-like illnesses. But none has contracted the mystery virus.
By Wednesday, 21 of the 38 patients had been discharged.
City residents worried about the outbreak have rushed to buy face masks from local pharmacies, with many selling out earlier this week. Inbound trains and flights from the mainland are undergoing extra cleaning and disinfection, the authorities said.
Additional thermal imaging systems have been set up at the city's airport, while inbound high-speed rail passengers from the mainland face checks by hand-held infrared thermometers.
Experts interviewed by the South China Morning Post said that while the virus has been identified, there are still important details that need answers.
Professor David Hui Shu-cheong, a respiratory medicine expert from the Chinese University of Hong Kong, said: "Some key information, including which animal is the source of the virus, the incubation period and the transmission route, is still missing."
Dr Ho Pak-leung, an infectious disease expert from the University of Hong Kong, said: "It would be necessary to check the supply chain as soon as possible and see whether similar animals were supplied in other wet markets out-side Wuhan."
AGENCE FRANCE-PRESSE, REUTERS