In total, 198 cases of the new coronavirus have been identified in the city of Wuhan, where the virus appears to have originated. At least a half-dozen countries in Asia and three U.S. airports have started screening incoming airline passengers from central China.
The cluster of the novel disease was initially reported on Dec. 31 last year at the Wuhan Seafood Wholesale Market, which has been temporarily closed to carry out environmental sanitation and disinfection.
The clinical signs and symptoms reported are mainly fever, with a few cases having difficulty in breathing, and chest radiographs showing invasive pneumonic infiltrates in both lungs.
It has been identified as a coronavirus, which can cause illnesses ranging from common colds to the potentially deadly Sars that killed more than 700 people around the world in the 2002-03 outbreak.
Some 763 people have been put under observation in Wuhan after coming in to close contact with known patients, health authorities said on Thursday. In China, three patients have already died due to the virus.
The Daxing health commission in the capital Beijing said it had confirmed two cases of coronavirus, while the southern Guangdong province’s health commission confirmed one case in Shenzhen. They mark the first cases in China beyond the central city of Wuhan where the virus first emerged.
Yet the Director and Chief Physician of the Wuhan Center for Disease Control and Prevention Li Gang affirmed Sunday that "the infectivity of the new coronavirus is not strong" and that the “risk of continuous human-to-human transmission is low."
There are two cases already reported outside mainland China. The first case was detected in Thailand on Monday, a 61-year-old woman who is in stable condition now; and a Japanese man who had fallen ill after visiting the Chinese city and died Thursday.
In Singapore, a third suspected case was reported on Thursday. The Ministry of Health said a 69-year-old man who traveled to Wuhan has been diagnosed with pneumonia.
While two Chinese tourists with fever symptoms from Wuhan were quarantined by Vietnam's Ministry of Health and are now under observation after in Hanoi on Tuesday.
The World Health Organization said Sunday that China had shared the genetic sequence of the virus, which is of great importance for developing specific diagnostic kits. The organization warned that a wider outbreak is possible.