Jan. 30 (UPI) -- Centers for Disease Control and Prevention officials Thursday confirmed the first "person-to-person" transmission of 2019 novel coronavirus in the United States. It's the sixth case in the country overall.
The new case, the second in Chicago, is the husband of the first confirmed travel-associated case in the city. The man did not travel to China -- a sign that the virus, known as 2019 n-CoV, spread as a result of close contact.
"The risk to general public in Illinois remains low," Ngozi O. Ezike, director of the Illinois Department of Public Health, said Thursday. The case involves an "extremely close contact. The virus is not spreading widely across community."
The United States is the fourth country to report human-to-human transmission, as South Korea also reported its first secondary transmission of the virus on Thursday. China and Germany have previously reported cases, and the World Health Organization said Wednesday there may be two more cases but did not identify their locations.
CDC Director Robert R. Redfield said Thursday experts don't know how easily or rapidly the virus spreads.
The agency is not recommending that Americans take any additional precautions -- such as wearing face masks -- beyond what would normally be taken to avoid any respiratory tract infection, including the flu -- namely, practicing good hand hygiene and staying away from others who are stick.
The U.S. State Department on Thursday issued a Level 4 travel advisory warning people not to travel to China due to the coronavirus.
Ezike said public health investigators working with the CDC are investigating several other close contacts of the Chicago woman since her return from Hubei province, China -- ground zero for the virus.
The woman, in her 60s, remains in the hospital and is doing well, Ezike said.
Her husband began reporting symptoms earlier this week. He was hospitalized and placed in isolation, and is also doing well, officials said. They received laboratory confirmation that he has 2019 n-CoV from the CDC on Thursday.
Officials believe the virus was passed from the wife to her husband after she was symptomatic. There has been some concern that 2019 n-CoV can be transmitted before symptoms arise.
The CDC is working with the hospital treating both patients to ensure that healthcare workers are properly protected.