Coronavirus risk low, but Bay Area is wary
Far from any cases, residents still snap up face masks
The new coronavirus that has sickened more than 6,000 people worldwide and killed more than 130 is causing major upheaval across China, the epicenter of the illness. It’s also alarming Bay Area residents who — at least for now — are at very low risk of illness, but are stocking up on face masks and asking health care providers for advice on protecting themselves and loved ones. At least two Bay Area counties have opened public health emergency centers this week to disseminate accurate and uptodate information about the outbreak. Several stores reported running low on masks, which are being sold to customers concerned for their own safety or who plan to send them to people in China.
The outbreak of the respiratory illness has the potential to become a major global health threat, and people in the U.S. should pay attention to updates about how to protect themselves, by avoiding travel to China, for example.
But public health and infectious disease experts said for now, people in the Bay Area and other parts of the U.S. should be far more concerned about influenza than the new coronavirus. That means they should wash their hands regularly
and stay home from work or school if they’re sick.
“There are a lot of people who are quite concerned (about the new virus),” said Sara Cody, Santa Clara County health officer. “But with just a few cases in the United States and none in the Bay Area, we have no evidence there’s humantohuman transmission here. We don’t have recommendations that people take any particular action.
“It is important to remember that we’re having a very busy flu season,” she added. “So we are really emphasizing that if you’re sick, stay home. And if you’re not, wash your hands a lot and make sure you’ve had your flu shot. As much as we can prevent what’s preventable, that’s great, particularly when everyone’s concerned about this new virus.”
As of early Wednesday, the new coronavirus had infected 5,974 people in China and dozens more elsewhere, though some infectious disease experts say that number is probably far higher with many cases not being reported or tested. The virus has been confirmed in at least 18 countries and four U.S. states.
Two cases of coronavirus have been reported in California, in Los Angeles and Orange counties; the three others are in Washington state, Illinois and Arizona. Nationwide, 73 possible cases are under investigation. The five confirmed domestic cases are people who recently were in China and almost certainly were infected there before flying to the United States.
Experts in global health threats said they were keeping a close eye on the outbreak because of the potential for a major epidemic. Coronaviruses are a common cause of mild illness, but three types have been responsible for large, serious outbreaks of respiratory illness: the current one, and the viruses that cause SARS and MERS.
SARS (severe acute respiratory syndrome) infected about 8,000 people and killed nearly 800, about 10%, before largely disappearing in 2003. MERS (Middle East respiratory syndrome) has infected about 2,500 people and killed nearly 900, or about 36%. The coronaviruses that cause those illnesses have fairly high fatality rates. But MERS is not easily spread from person to person. And SARS, though more easily transmissible, is not as infectious as other respiratory illnesses like the flu.
For the new coronavirus — which was identified only a month ago — scientists are still trying to determine how contagious it is, and how severely ill it makes people.
“So far we’re looking at a disease with a case fatality rate of 2%. That’s a very different kettle of fish from SARS or MERS,” which were far deadlier, said George Rutherford, head of the division of infectious disease and epidemiology at UCSF. “But there’s obviously a lot we don’t know. There may be even lower mortality because there are a lot of mild cases that haven’t been diagnosed. Or there may be a higher mortality.”
Scientists do know that the new virus is able to spread from human to human, and likely via the respiratory system, meaning people infect others through sneezes or coughs.
But there’s a broad range in how easily a respiratory pathogen spreads. Measles, for example, is one of the most infectious diseases in the world because it spreads via tiny particles that can float around a room and infect people hours after the original patient has left the space. Other viruses and bacteria require more direct contact, such as droplets from a sneeze coming into contact with another person’s eyes, nose or mouth.
Other key questions about the new virus are whether people are able to spread it before they show symptoms, and how long the incubation period is. So far, it looks as though the virus may incubate in people for up to two weeks before they show symptoms. Whether they can infect others in that period will make a huge difference in how the illness spreads.
“The risk to the general public — someone sitting on a bus or whatever — is actually quite minimal now,” said Art Reingold, an epidemiology expert at the UC Berkeley School of Public Health. “I’m going to guess that people will not transmit very effectively. My guess is we may see secondary transmission to household members or close contacts. But I don’t think we’re going to see sustained transmission or casual transmission in the United States. That’s my hope and expectation. I could be wrong, of course.” Staff writer Alejandro Serrano
contributed to this report.