U.S. authorities on Friday are set to begin screening travelers arriving in the country from Wuhan, China, amid an ongoing outbreak of a novel viral infection there that has already led to cases among travelers in two other countries.
Passengers arriving from Wuhan in San Francisco and Los Angeles and at New York’s John F. Kennedy International Airport will be checked for symptoms of the infection, which include cough, sore throat, and fever. The Centers for Disease Control and Prevention is deploying 100 extra staff members to the three airports to help with the screening of the virus, which experts have determined to be part of a group called coronaviruses and are calling 2019-nCoV.
While the overall risk to people in the United States is low, “we know it’s crucial to be proactive and prepared,” Dr. Nancy Messonnier, the director of CDC’s National Center for Immunization and Respiratory Diseases, said on a call with reporters.
Messonnier added that this was still the early days of the outbreak and that the CDC’s policies could change as more is learned about the virus.
CDC officials picked the three airports because they see the majority of passengers arriving from Wuhan. JFK and San Francisco have direct flights from and to Wuhan, and Los Angeles also welcomes many connecting passengers.
“The earlier we detect a case, the more we can protect the public,” said Dr. Martin Cetron, the director of CDC’s Division of Global Migration and Quarantine.
Passengers will be asked about their health and checked for symptoms. People who show symptoms will undergo a secondary screening to determine whether they might have some other respiratory infection — a strong possibility during cold and flu season — or need to be tested for the coronavirus.
Officials said that verifying a case of the novel coronavirus right now could take a day because patient samples need to be shipped to the CDC in Atlanta for testing. But they said they are working to expand their diagnostic capabilities so confirmation can happen faster.
The U.S. joins several other countries, primarily in Southeast Asia, that have been screening passengers from Wuhan for signs of the virus. Global health authorities are on particular alert because of the millions of people expected to travel around the upcoming Lunar New Year holidays.
Pneumonia cases tied to the virus were first reported in Wuhan — which is about 700 miles south of Beijing — last month. Since then, local officials have confirmed 45 cases, including two deaths of older patients, one of whom had other health conditions.
Japan and Thailand have both confirmed cases of the virus in travelers from Wuhan, with Thailand reporting a second case on Friday. The new patient, a 74-year-old woman, was not a contact of the first case in Thailand.
Most of the cases have been tied to a large seafood market that also sold the meat of various animals. Coronaviruses, which include SARS and MERS, originate in bats but can spread to other animals, and from there, jump to humans. The market has been closed since Jan. 1.
However, some patients, including the original case in Thailand and the case in Japan, reported not visiting the Huanan seafood market. That suggests that there’s another source of the virus, perhaps at another market, or that person-to-person spread is possible.
“There is some indication that limited person-to-person spread is happening,” Messonier said.
Researchers are still trying to determine the source of the outbreak, the incubation period of the virus, and, if humans can transmit the virus to others, how often that occurs. Health authorities in Wuhan have tracked 763 contacts of the infected people there, including more than 400 health workers, and have not identified any subsequent infections among them.
The novel coronavirus has raised memories of the 2003 SARS outbreak, when that virus spread from China to Hong Kong and on to Vietnam, Singapore, Taiwan, and Toronto, killing nearly 800 people.
Some experts have questioned whether there might be more cases in Wuhan than reported so far, suggesting that 45 confirmed cases there seems low given that there have already been three identified exported cases.
CDC officials said they expect more cases to be identified in China and elsewhere as awareness spreads about the virus and diagnostic capabilities improve.
“There might be more cases, but we really need to wait for our colleagues in China to complete their investigation,” Messonnier said.