U.S. Health Secretary Alex Azar warned Tuesday that the coronavirus raging across mainland China is a "potentially very serious public health threat," saying that the Trump administration is expanding screening for the virus from five to 20 U.S. airports.
"We are constantly preparing for the possibility that the situation could worsen," Azar said during a press briefing on the nation's response to the coronavirus, which has killed 106 people in mainland China and infected nearly 4,700 worldwide, including in the United States.
"Americans should not worry about their own safety," Azar said. "Part of the risk we face is we don't know everything we need to know about this virus ... That does not prevent us from preparing and responding."
The U.S. Centers for Disease Control and Prevention earlier in the day advised Americans to avoid all non-essential travel to China, expanding its travel warning from the city of Wuhan, the epicenter of the outbreak, to the entire country.
"To better protect the health of the American public during the emergence of this novel coronavirus and based on the evolving information from China, CDC has reassessed its entry strategy," CDC Director Robert Redfield said at the press briefing.
CDC officials said the screenings will focus on identifying ill patients as well as educating travelers so they can help contain the disease.
Coronaviruses are a large family of viruses that usually infect animals but can sometimes evolve and spread to humans. Symptoms in humans include fever, coughing and shortness of breath, which can progress to pneumonia.
U.S. health officials said Tuesday that they are still determining the real speed and spread of the disease and whether it can infect people prior to symptoms. Azar said the so-called R naught, a mathematical equation that shows how many people will get an illness from each infected person, appears to be somewhere around 1.5 to 3. Azar said symptoms from the new virus, temporarily named 2019-nCoV, may take up to 14 days to appear.
Azar said he offered to send CDC officials to China to assist public health officials there. "We are urging China [to act] with more cooperation and transparency," he said.
CDC officials said Monday that the number of "patients under investigation" in the U.S. has almost doubled since Thursday to a total of 110 across 26 states. The disease is not spreading through human-to-human contact in the U.S. and the risk to the public right now is still considered low, Dr. Nancy Messonnier, the director of the National Center for Immunization and Respiratory Diseases, said Monday.
German officials confirmed Tuesday what is believed to be one of the first person-to-person transmissions of the infection outside of China.
Several companies, including Walt Disney with its Shanghai Disney, are suspending operations in China during the normally festive weeklong Lunar New Year holiday to prevent the outbreak from spreading. Starbucks and McDonald's also closed stores in Hubei province, where Wuhan is located.
According to the World Health Organization, more data needs to be collected before the virus is declared a global health emergency. WHO declined at two emergency meetings last week to say it was a worldwide emergency.