China confirmed Wednesday that 440 patients have been infected at home by a new coronavirus, up by more than 100 from the previous day, as the outbreak killing nine people has been found to have spread from Asia to the United States.
The nine have died of pneumonia caused by the new virus, which is believed to have originated in the central city of Wuhan, the Chinese government said at a press conference, with the virus being newly found in Macau and Hong Kong a day after emerging in Taiwan.
On Tuesday, a man residing near Seattle has been diagnosed with the new coronavirus after traveling to China, the Centers for Disease Control and Prevention said -- the first confirmed case in the United States and the first outside Asia.
Fears are growing that the number of those infected by the virus would surge not only in Asia but all around the world, as many Chinese people are set to travel during the Lunar New Year holidays that start Friday.
The news conference was the first one held by the Chinese government over the new virus since reports of mysterious pneumonia cases in Wuhan surfaced in late December, and apparently signals Beijing's commitment to information disclosure.
The Cabinet-level National Health Commission pointed to an expert view that the novel virus -- the vast majority of whose cases have so far centered on Wuhan -- may spread further through mutation as it has become evident that it can be passed between humans.
The commission stressed that the country will step up international cooperation in containing the outbreak, amid reports the virus has spread to other nations, including Japan and Thailand.
As of midnight Tuesday, the death toll in China had increased from six to nine, and the number of confirmed cases of respiratory problems due to the virus risen from about 320 to 440, according to the government.
Li Bin, vice minister of the commission, told the press conference the recent jump in the cases can be attributed to improved detection methods, accompanied by a deeper understanding of the disease.
All the deaths have occurred in Hubei Province, whose capital city is Wuhan, he added.
Given that millions of Chinese are likely to travel domestically and internationally for the New Year holidays, the government will implement stronger controls on movements in and out of Wuhan, and restrict public gatherings in the entire province, Li said.
In Wuhan, located around 1,000 kilometers south of Beijing, a Tokyo Olympics boxing qualifying tournament was scheduled to take place next month, but it has been canceled in order to protect the safety and health of those attending, organizers said Wednesday.
Thailand, South Korea and Japan have confirmed cases of infections, while Taiwan and the United States both reported on Tuesday their first cases of pneumonia caused by the new virus.
On Wednesday, Macau announced its first coronavirus case, while in Hong Kong, local media reported on the same day that a person has been diagnosed with the new coronavirus, which is also the first confirmation in the city.
North Korean authorities, meanwhile, blocked foreign tourists crossing the border from China on Wednesday as a preventive measure after the outbreak in its neighbor, according to tourist companies.
In Taiwan, President Tsai Ing-wen announced a ban on entry into the island of tour groups from Wuhan. The ban, she said, will expand to other areas of China should the spread of the coronavirus pick up pace.
Later Wednesday, the World Health Organization is expected to hold an emergency committee meeting in Geneva to discuss whether to designate the outbreak as a public health emergency of international concern.
Coronaviruses usually cause common-cold symptoms affecting the nose, sinuses or upper throat, and are spread through sneezing, coughing or direct contact.
Some types, however, lead to more serious, sometimes deadly respiratory diseases, such as severe acute respiratory syndrome or Middle East respiratory syndrome, known as SARS and MERS, respectively.
Medical experts have called for people to wash their hands, gargle, and wear masks as a preventative step as influenza and colds are common in this period.
In Beijing, masks have sold out at many supermarkets and convenience stores.