5 more people in the United States who recently traveled to China have been diagnosed with the coronavirus.
The officials from the Centres for Disease Control (CDC) said two new cases were reported on Sunday one in Los Angeles County, California, and the other in Maricopa County, Arizona.
The latter case was someone with ties to Arizona State University who did not live in school housing, state health officials said.
3 cases previously reported were a patient in Orange County, California; a man in his 30s in Washington; and a woman in her 60s from Chicago.
It is understood all five patients recently travelled to the Chinese city of Wuhan, where the disease is believed to have originated.
US patients have generally been reported to be in good condition and were hospitalized in isolation for monitoring.
The confirmation of the five cases came as Canada declared its first “presumptive” confirmed case of the disease over the weekend, and as officials in Beijing warned the disease is likely to spread further.
Ma Xiaowei, China’s national health commission minister, told a news conference that the incubation period for the coronavirus the period between exposure to the virus and the appearance of first symptoms could range from one to 14 days. He said the disease was infectious during that period, something not the case with the Severe Acute Respiratory Syndrome (SARS) that claimed nearly 800 lives during the 2002-2003 epidemic that also originated in China.
“At present, the rate of development of the epidemic is accelerating,” Mr Ma said. “I am afraid that it will continue for some time, and the number of cases may increase.”
Also on Sunday, the World Health Organisation’s director-general said he was on his way to China to confer with officials and health experts about the outbreak.
In a tweet, Tedros Adhanom Ghebreyesus said he wanted to “strengthen our partnership” with China “in providing further protection against the outbreak”.
Chinese authorities say it has infected over 2,000 people and killed 56.
The US is among those countries scrambling to withdrew personnel from the city of Wuhan.
The state department said on Sunday it would be evacuating staff from the city on Tuesday in a direct flight to San Francisco.
It said it would also book a limited number of US citizens on the flight if there were requests. It said if demand was high priority would be given to Americans at higher risk.