Health officials announced a second confirmed US case of a patient with the new Chinese coronavirus on Friday and said they are monitoring another 62 possible patients in 22 states suspected of having the illness.
All of the patients are travelers from Wuhan, China, the epicenter of the new coronavirus, or 2019-nCoV, outbreak that Chinese health officials by Friday evening reported has caused more than 1,287 cases and 41 deaths. The first US patient, a Washington state man in his thirties, was announced on Tuesday, and the second one, a Chicago woman in her sixties, were both recent travelers to Wuhan. Both arrived in the US before an extensive travel ban from the city was started this week by the Chinese government.
"We expect to find more cases," said CDC's Nancy Messonnier, director of the National Center for Immunization and Respiratory Diseases, on a telephone briefing for reporters. Noting that the two confirmed cases were travelers from Wuhan, she said that the risk to the US of a widespread outbreak is low. "We are making an aggressive response to identify these cases early."
Both of the confirmed cases entered US airports without symptoms, she noted, and contacted their doctor a few days afterward, leading to their diagnosis and medical isolation. The CDC did not provide a list of the 22 states with possible cases, but a possible case in Texas was confirmed by Texas A&M University on Thursday. Eleven additional people suspected of having the coronavirus were screened and tested negative, according to Messonnier.
The first Chinese cases of the coronavirus were reported on Dec. 31 and traced to a seafood and meat market in Wuhan. Like SARS and MERS, the virus is thought to have traveled to people from animals and mutated to become transmissible from person to person. Cases have been reported in Japan, Thailand, Vietnam, Singapore, and Taiwan, as well as the US.
The Chinese ban on travel from Wuhan was expanded this week to cover much of its central Hubei Province, essentially quarantining 35 million people during the travel-heavy Chinese New Year. Partly in response, a World Health Organization panel on Thursday declined to recommend a global emergency declaration over the outbreak, arguing that most of the cases were confined to China, where aggressive measures were being undertaken to prevent the spread of the virus.
On the telebriefing, Allison Arwady, the chief medical officer at the Chicago Department of Public Health, suggested that the risk of virus contagiousness appears lower before patients manifest symptoms of the pneumonia-like illness, such as fever, cough, headaches, and difficulty breathing. The Chicago patient is in stable condition, said Arwady. She did not use public transportation or attend public gatherings before she became sick.
So far, CDC has screened about 2,000 travelers from China for the disease on about 200 flights, CDC's Martin Cetron said, but have not found any cases. The agency is reevaluating the screening taking place now at five US airports, in Atlanta, Chicago, Los Angeles, New York, and San Francisco, in light of the Chinese travel ban, he added.
"This is an evolving situation and information is coming in almost hour by hour," Messonnier said. "We are expecting more cases in the US and we are likely to see these cases among close contacts of patients."