Fears rise with virus from China now in U.S.
The first case of a deadly new respiratory virus with the potential to become a major global threat was reported Tuesday in the United States, in a man in Washington state who had traveled to the region in China where the illness appears to have originated.
The new coronavirus is related to the virus that caused SARS, which sickened several thousand people worldwide 18 years ago. Public health officials worldwide are now racing to learn more about the new virus, including where exactly it came from, how easily it spreads among people and how it can be stopped.
“There’s concern this could spread like the SARS virus did,” said Dr. Jeffrey Silvers, medical director of infectious disease at Sutter Health in the Bay Area.
U.S. public health authorities put out their first alerts about the new virus two weeks ago, and over the weekend began screening passengers arriving from Wuhan, China, to three airports — San Francisco International Airport, New York’s John F. Kennedy International Airport and Los Angeles International Airport.
Two more airports, in Chicago and Atlanta, will be added later this week.
The Washington patient, who reported himself to public health authorities and is in good condition, had traveled into the United States last week, before federal officials put in place screening protocols to identify cases of the new coronavirus.
The virus so far has sickened 440 people, mostly in Wuhan province in central China, and nine deaths were reported as of Tuesday. The American patient was confirmed Tuesday morning by the U.S. Centers for Disease Control and Prevention. The man is a U.S. resident from Snohomish County who is currently hospitalized and in isolation.
“The threat to the public at large remains small at this time,” said Dr. Nancy Messonnier, director of the National Center for Immunization and Respiratory Diseases at the CDC, in a news conference Tuesday.
The new virus was first reported in China at the end of December, with a few dozen patients hospitalized with a mysterious pneumonia. The cases were linked to an outdoor seafood market in Wuhan where live animals were being sold.
Within a week of the first cases being announced, scientists discovered that a coronavirus was the cause. Very quickly, genomic sequencing found that it was unlike any coronavirus previously identified.
Coronaviruses are a family of pathogens that mostly cause mild symptoms associated with the common cold. But two have been found to cause much more serious illness in humans. A coronavirus caused SARS (severe acute respiratory syndrome), which infected about 8,000 people and killed nearly 800 worldwide before petering out. Another coronavirus causes MERS (Middle East respiratory syndrome), which has infected about 2,500 people, mostly in the Middle East, and killed nearly 900.
For both MERS and SARS, the outbreaks began when a coronavirus jumped from an animal source into a human — that’s why scientists are interested in whether patients with the new disease were exposed to animals at the seafood market in Wuhan.
The SARS virus turned out to be very good at transmitting from human to human, which was why it spread so rapidly around the world. The outbreak was stopped in part by aggressive public health efforts worldwide to quarantine patients, though infectious disease experts said there are still some questions around why it went away.
The MERS virus is not so easily spread among humans, but it is now endemic in camels in the Middle East, which may explain why the disease has lingered, said Dr. Charles Chiu, an infectious disease expert who heads the viral diagnostics laboratory at UCSF.
It’s too soon to know where exactly the new virus came from, how easily it spreads or how dangerous it is. Reports have confirmed that the virus is indeed spreading from human to human, and Chinese health authorities this week reported that 14 health care workers had become ill after being exposed to sick patients.
“The worstcase scenario is an animal reservoir that harbors the virus as well as efficiency of humantohuman transmission. That’s a recipe for disaster,” Chiu said. “We can’t really answer that question yet.”
Bay Area infectious disease experts said they are following the ongoing outbreak closely, though the immediate risk to Americans is low. If people are feeling sick right now, they’re far more likely to have the flu or some other common virus.
Anyone who has recently been to Wuhan and develops a fever and lower respiratory symptoms, such as a cough or shortness of breath, should contact their local public health department or their own doctor, Silvers said. He said he sent out a notice to health care workers at Sutter on Tuesday, advising them to be alert for possible cases of the new illness, and to ask patients with respiratory symptoms about their recent travel history.
Silvers noted that the experience with SARS in particular helped public health and infectious disease experts prepare for other potential outbreaks like the new coronavirus.
The Washington patient arrived in Seattle last Wednesday and did not have any symptoms at the time. When he began to feel ill four days later, he knew that his recent travel had put him at risk of the new virus, so he called his doctor. He was then admitted to a hospital for monitoring. Public health officials said
Tuesday that they were interviewing the patient about his travel history and people he might have come into contact with recently.
Infectious disease experts said it’s possible more cases will show up in the United States. And depending on how easily transmissible the virus is, it may be difficult to halt spread of the illness. The first line of prevention at the moment is quickly identifying new cases, which largely involves airport screening.
Starting this week, all people traveling from Wuhan into the United States will be forced to travel through one of the five airports, including SFO, picked for screening by the CDC. Passengers going through customs will be asked about their travel history, including whether they have visited a seafood market, and will be checked for fever.
SFO gets three direct flights from Wuhan per week, each averaging about 150 passengers, but it wasn’t immediately clear how many additional passengers would be screened once more flights are funneled through the airport.
“We have a lot of people coming from China to this area, and if somebody came from Wuhan and they were sick, I’d tell them to stay home. I’d want to make sure they were checked,” said Dr. Yvonne Maldonado, medical director for infection control at Lucile Packard Children’s Hospital at Stanford. “But the risk to the average person is probably going to be pretty low right now. People need to be cautious, but no one should panic.”
“But the risk to the average person is probably going to be pretty low right now. People need to be cautious, but no one should panic.”
Dr. Yvonne Maldonado, Lucile Packard Children’s Hospital