The United States confirmed its first case of human-to-human coronavirus transmission Thursday.
The latest case involves an patient who is married to a Chicago woman who got sick from the virus after she returned from a trip to Wuhan, China. The new patient had not been in China.
The case is the sixth reported in the country.
All previous cases in the U.S. were of individuals who had travelled to China. There have been cases reported of the infectious virus spreading to others in a household or workplace in China and elsewhere.
The U.S. Center for Disease Control and Prevention said the threat level in the country remains low. U.S. experts had said they expected additional cases, and that at least some limited spread of the disease was likely.
At a press briefing last Friday, the CDC’s Dr. Nancy Messonnier said: “We are likely going to see some cases among close contacts of travellers and human-to-human transmission.”
Health officials think the new virus spreads mainly from droplets when an infected person coughs or sneezes, similar to how the flu spreads.
On Thursday, China reported its death toll from the illness to be 170. Of the latest deaths, 37 were in Hubei province, of which Wuhan is the capital. One death was in the southwestern province of Sichuan.
Outside China, there are 82 infections in 18 countries, according to the World Health Organization.
— With files from The Associated Press