A Chicago woman has become the second US patient diagnosed with the new pneumonia-like virus from China, health officials announced.
The woman in her sixties returned from China on January 13 without showing any signs of illness, but a few days later she called her doctor to report feeling sick.
The patient is doing well and remains in hospital “primarily for infection control”, said Dr Allison Arwady, Chicago’s public health commissioner.
People that the women had close contact with are being monitored.
Earlier this week, a man in Washington state was diagnosed with the virus after returning from a trip to China.
Dr Nancy Messonnier, of the Centres for Disease Control and Prevention (CDC), said the risk to the US public remains low but it is likely more cases will be diagnosed in the coming days, as the virus appears to have a two-week incubation period.
Nationally, more than 2,000 returning travellers had been screened at US airports and 63 patients in 22 states were being tested, although 11 of them so far have been found free of the virus, the CDC said.