Q&A on SARS: Tomás Aragón of the UCB Center for Infectious Disease Preparedness, on what we know and what we can do
BERKELEY - In the past month, a mysterious, highly contagious respiratory disease has rapidly spread around the world, involving 16 countries. As of April 10, Severe Acute Respiratory Syndrome (SARS), which shares many of its symptoms with other, more common respiratory illnesses like colds or flu, had infected some 2,700 people and killed 111 people. An overwhelming majority of cases have been in mainland China and Hong Kong. No cases have been reported on the Berkeley campus.
To recommend measures to protect students, staff, and faculty at Berkeley, Chancellor Robert Berdahl has appointed a SARS task force. Among its members is Tomás Aragón, director of the UC Berkeley Center for Infectious Disease Preparedness. George Strait, assistant vice chancellor for public affairs, sat down with Aragón to find out what we know about SARS and what measures are possible to prevent its spread.
Q. Information is changing by the hour, but what do we know about SARS?
A. What we know right now is that the SARS virus is almost certainly from a family called coronaviruses. The outbreak was initially detected in Vietnam — a person who was exposed to the index case in the Metropole Hotel in Hong Kong traveled to Vietnam. Then there was an outbreak of infection in the health care workers, and one of the clinicians in Vietnam realized that this might be a bigger issue. That’s when the World Health Organization (WHO) got involved in figuring out what was happening in Hong Kong, in Vietnam, and then in China.
As far as we can tell, this is a new virus. It’s a respiratory tract infection that causes pneumonia and respiratory failure. About one out of 10 persons with SARS develops respiratory failure requiring ventilation. A smaller percentage of that, about 3.5 percent of the total, have died so far.
We don’t now have effective treatment for SARS, and it’s very transmissible. However, it’s not transmissible in the same way as some other respiratory tract infections, such as tuberculosis, or even like chicken pox or measles. In these illnesses, you get aerosolization of the virus that lasts in the air for hours so that the disease is very, very infectious. In contrast, the SARS virus, as far as we can tell, is spread primarily by large respiratory droplets, which are not suspended in the air for a long time, so you really have to have close contact with an infected person.
Q. Can SARS be spread by touching surfaces contaminated by an infected person?
A. When somebody coughs or sneezes, they can contaminate surfaces — tables, telephones, door knobs. So if people touch these surfaces and then touch their nose or mouth, for example, they can get infected. So, while it’s not as infectious as influenza, that’s still pretty infectious. And with a mortality rate of around 3.5 percent, if we assume that most of the world’s population is going to be susceptible, it really has the potential to make a lot of people sick and cause a large number of deaths.
Q. Is there a diagnostic test?
A. As of today, there is not a diagnostic test. We hope within a week or two we’ll have diagnostic testing available at state labs so that if doctors think they see someone who has SARS they can collect a specimen and send it to the state health department to get it confirmed. That will be really important for our control efforts. We will focus on people we know are infected with the virus. Because the symptoms can be so common, we don’t want to waste a lot of our public health resources in worrying about people who don’t have SARS.
Q. Until we do that, there is a definition to discover whether or not a person has SARS. What is that definition, and how bound by it should we be as we try to deal with people who are sick?
A. The CDC has come up with what they call a “case definition” to help us track how the infection is spreading. The case definition is loose enough so that we can make sure it [casts a wide enough net to identify cases and] help control the spread of the infection. So the case definition that they’re using is this: anybody who has a fever of greater than 38ºC, or 100.5ºF, and has respiratory symptoms, and has either come from a country where SARS has been identified (currently China, Hong Kong, Vietnam, and Singapore) or has had contact with somebody who had SARS.
If doctors can identify influenza or another condition in a patient, then it’s unlikely that they have SARS. But if we rule these out, you have what physicians call a diagnosis of exclusion — you’ve ruled out the things that we do know about and what’s left over is an undiagnosed condition that meets the case definition. It’s then considered a SARS case.
Q. Suppose somebody has just come back from Vietnam, has sniffles, and is running a low-grade fever. What should they do, and how should health care workers treat them?
A. It’s a good idea, in general, that anybody who has a respiratory tract infection (since we don’t know exactly what we’re carrying) should be careful that they’re not transmitting it to others. So first, we need to practice common sense rules that we all know but don’t always follow. Common sense will reduce transmission of a lot of common respiratory viruses.
For instance, people should cover their mouths when they cough, preferably with a tissue, so they’re not easily contaminating their hands. And we should all wash our hands frequently.
When patients arrive at a clinic with a respiratory tract infection, they should be asked to put on a mask. By actually covering the person who’s sick, you dramatically reduce how infectious that person is. What you don’t want is to have people in the waiting room infecting others. Patients don’t come to the doctor with the expectation that they’re going to leave with another disease. Actually, in two cases reported in the New England Journal of Medicine, that’s how people got infected. They were in the waiting room and were infected by a patient who was there to see the doctor.
Q. So someone who walks into an ambulatory care center and sees people with masks on shouldn’t be afraid of them.
A. Absolutely! They should not be afraid of them. They should say, “My doctor’s doing his or her job.”
Q. What about public health officials? Should they handle SARS aggressively?
A. Health officials are struggling with this, just how aggressive to be. I think health officials are always cognizant of the fact that when they implement control strategies, it can affect the economy, it can affect travel, and it can affect people’s livelihoods. If you’re asking people to stay home and not go to work, those are real issues. Health officials really weigh all these issues carefully. In general, I think they’re going to side on what they think is best for public health, even if they know it’s going to have an economic impact.
As a society and as a world, we have to decide if we are going to eradicate this or just try to slow its spread. Those are two very different strategies. It may be that even if we decide that we’re going to try to eradicate SARS — which means recommending limitations of travel, being aggressive in isolating people who are sick, preventing them from going to work and infecting other people — in spite of your best efforts, it still might spread.
On the other hand, if you don’t give it your best effort and it spreads, you’ve lost the opportunity for eradication once it’s become endemic.
If this becomes endemic in the world, we’re going to hope that people are going to have some type of persistent immunity, so the next time they get infected it won’t be serious. The coronaviruses can actually re-infect people.
Q. If you don’t eradicate it, and it becomes endemic in certain parts of the world, you haven’t really solved any of these economic or travel issues, right?
A. Right, absolutely, and that’s what Hong Kong was struggling with. People say, “No, no, we need to travel, we need the tourism, we need the business,” and one of the public health officials says, “Look, it’s happening anyway, whether you like it or not, people are not going to come here. We’re making a public health statement that makes absolute sense, and you’re just going to have to accept it.” We really need to deal with this now, because if we don’t, there will be a longer period when travelers won’t be able to return to areas where the outbreaks have been occurring.
Q. On campus, what should we be doing?
A. It’s important for us not to have a “wait-and-see” attitude. It’s important for us to be proactive in thinking through the things that can happen here on campus. We want to educate people on the basic things they can do to prevent getting infected from general respiratory viruses. I think the basic stuff goes a long way toward keeping people healthy. We want to get people accustomed to the idea that you may be sitting on a bus and see someone wearing a surgical mask, so just recognize that this may become a regular occurrence, go with the flow, and accept it. The day may come when you have to wear a surgical mask, and you don’t want people stigmatizing you and treating you differently.
I think we are going to have to make a cultural shift. In Asia, people wear masks for other reasons, such as pollution, so it’s not as much of an issue to see somebody with a mask on. We may need to get used to some of that, at least temporarily, until we see how this plays out. It may be that if we don’t eradicate this thing, 20 years from now, we hope, it’ll be a regular occurrence that doesn’t cause a lot of illness because the population has developed immunity. Until that time comes, we’re going to have to go through a transition here where we may be doing things that we’re not accustomed to.
Q. How are we preparing ourselves on campus?
A. The task force has been identifying the key issues that they’re going to have to struggle with. One is what to do about students who are going to be traveling abroad to programs or to do research. The task force, right now, recommends following current CDC guidelines on unessential travel to areas where outbreaks have been occurring. We’ll revisit their policy and guidelines repeatedly to see whether those should change.
The other issue is for the university to provide resources and education for those who feel they must continue their work abroad, so they can minimize the risk of getting infected or bringing back an infection.
We also need to talk about what to do if someone develops SARS in a campus residence hall. The details of that still have to be worked out, but the university does have a public health response team that deals with outbreaks in the student setting, and they’ll evaluate the situation and make recommendations to minimize the spread of disease.
To keep the campus informed, the Chancellor, the Tang Center, and Public Affairs will put together information on the Web and via e-mail to provide regular updates on how the situation’s changing.
Q. So if you were the parent of a student at Cal, how would you feel about how the university is gearing up to protect your student?
A. I think that Berkeley is being proactive in creating a campuswide task force with representation from local public health. It makes a lot of sense. I would be confident that the university is doing everything it can.