Chicago health officials have reported the first US case of human-to-human transmission of the deadly coronavirus.
The new patient is the spouse of a Chicago woman who carried the infection back from Wuhan, China, the US Centers for Disease Control said on Thursday.
The discovery marks the second report of the virus in Illinois and the sixth confirmed case in the US.
More than 130 people have died in China – the epicentre of the outbreak – and nearly 6,000 have been infected.
The virus has spread to every region in China and to at least 16 countries globally, including Thailand, France, the US and Australia, with the global death toll rising to 170.
There is no specific cure or vaccine, though a number of people have recovered following treatment.
Chicago health officials said the new patient, a 60-year-old male, had “some underlying medical conditions” but was in good condition. His wife, who he apparently contracted the virus from, was also stable but remained in isolation at a local hospital, officials said. She had been caring for her father in Wuhan, China, earlier this month.
Health officials are also monitoring 165 patients across the US for possible infections.
Dr Robert Redfield, the director of the Centers for Disease Control and Prevention, cautioned the US public to remain calm. “Our assessment remains that the immediate risk to the American public is low,” he said.
The American Airlines pilots’ union said on Thursday that it was suing the airline in an attempt to prevent to stop flights between the US and for China. The union said in a statement that it had instructed members to turn down requests to fly to China.
WHO declares international emergency
Also on Thursday, the World Health Organisation (WHO) declared the epidemic an international public health emergency, citing concern that the virus could spread to countries with weaker health systems. The WHO said there had been 98 cases in 18 countries outside of the country, but no deaths.
A number of countries have implemented evacuation and quarantine plans for nationals wanting to return from China, where the outbreak began in the city of Wuhan. Russia closed its 4,300km (2,670-mile) far-eastern border with China in an attempt to stop contagion.
WHO Director-General Tedros Adhanom Ghebreyesus said this week that while the numbers outside of China remained “relatively small” the risk of person-to-person transmission meant the “potential remains for a much larger outbreak”.
More people have now been infected in China than during the Sars outbreak in the early 2000s, but the death toll so far remains lower. Sars, also a coronavirus, caused the deaths of 774 people worldwide.
Learn more about the new virus
Please include a contact number if you are willing to speak to a BBC journalist. You can also contact us in the following ways: