With the World Health Organization raising its global pandemic alert level, and its Director-General advising all countries to immediately activate pandemic preparedness plans, it's hard to judge exactly how concerned people should be about swine flu—or what actions we should take. Yesterday, I talked to Brian Currie, MD, MPH, medical director of research at Montefiore Medical Center in New York City. He's an expert in pandemic preparedness and, as a specialist in infectious disease, also treats patients. Here's what he told me.
Dr. Currie, how worried should we be?
We should be worried. We have a very serious swine flu virus that's developed the ability to infect people, and there appears to be rapid person-to-person transmission. So that's already two of the characteristics you need for a pandemic. The only question is how serious it's going to be, and on that score I'm starting to feel a little reassured.
Why is that?
We're starting to see a number of cases now in the United States, and most of them have been pretty mild. That gives you some sense that the virulence of this virus isn't off the charts. We've had one death, but that's consistent with normal flu. People forget that 40,000 people die each year in the United States from seasonal flu. Many more people in Mexico have died, but it's beginning to look like the number of people who have been infected is larger than we might have thought. The denominator's been the question-how many people have gotten sick. They've been trying to pinpoint the index case [the epidemic's first case] in Mexico, and it looks like there may have been cases as far back as early March. So there have been lots of cases, and in a strange way that's reassuring. It means that this virus may not be more virulent than the normal flu.
I think a lot of people were surprised to hear about any kind of flu problem in April—I know I've always thought of flu as a seasonal issue. Was I mistaken?
Largely, the flu is seasonal, although we do get stray cases thoughout the year. But that's the regular flu. Historically, pandemic strains have not respected seasonality as well, so we don't know what's going to happen this time.
Also, there's frequently an uptick in cases of normal, seasonal flu around now, at the end of the season. And that's making it a little harder to tell what's going on here in New York, where we're getting reports of new cases—are we seeing that normal intensification, or are these cases of swine flu?
Do we know what's most important in spreading swine flu—aerosol transmission? Or people touching germy things and then touching their faces?
Flu is spread through droplets in the air—they go three feet out when a person coughs. Fomites are important, too. Those are inanimate objects that can spread the disease. Respiratory secretions get on the surfaces, and we know flu can survive on surfaces for 24 or 48 hours. If you touch them and then touch your eyes or nose, you can become infected.
Which is another reason we should all be alert to the need to wash our hands frequently. And also I think people don't realize how often they touch their faces.
Correct. Wash your hands. Simple soap and water will do. Wash whenever you think the circumstances warrant it, or use sanitizer. And you might want to think about sanitizing your phone if you're in a shared space.
With a Lysol-type spray?
Yes, anything like that. Even detergent will do. The flu virus is easily disrupted. Doorknobs and telephones, those sorts of objects get easily contaminated.
We've all seen pictures of people in Mexico wearing masks. If things get bad here, is that worth doing?
Masks are useful to prevent transmission in a clinical setting. But we use them on the patient, to block the droplets from being expelled into the air—they're not so useful if a healthy person wears one in order to prevent himself or herself from being exposed. The logic behind wearing masks ignores several possible routes of exposure, like your eyes.
I'm assuming people should not try to stock up on anti-virals like Tamiflu or Relenza—is that right?
It's too late, anyway, at least in the New York area. People have already bought up all of the Tamiflu and Relenza that were available in non-hospital settings. It's too bad, because it makes it hard to discharge patients if they can't fill a prescription for an antiviral.
That's why we want to manage our supplies; you really want to be able to give severely ill people these drugs. They make a big difference.
People have to take these drugs in the right way at the right time to help themselves, isn't that correct?
Yes. And there are side effects that go with Tamiflu—the most common one is gastrointestinal upset.
What makes it a little more complicated is that we still have regular flu strains circulating. Those are resistant to Tamiflu, while the swine flu is susceptible to the drug. So when we treat, we have to give two drugs, one to cover swine flu, and something else in case it's human flu.
Relenza would cover both, but that's very difficult to administer. It's a powder you have to inhale, not a pill. Some patients with asthma or respiratory disease are going to get bronchial spasm. Or people end up medicating their mouths instead of their lungs.
Timing is a consideration, too. Isn't there a window of opportunity?
They need to be given within 48 hours of onset.
Do these drugs also help prevent illness—if, say, you're a family member of a patient?
Yes. Tamiflu is about 70 percent effective. If you give it to ten people who have been exposed, it will prevent illness in seven of them.
What signs and symptoms should send someone to the doctor, especially given that you want to get there within that 48-hour window?
You'll have an abrupt onset of fever of 102 degrees or higher, you'll have cough, body aches, you may have some shortness of breath, and you can be flat on your back in bed within hours—that's how debilitating it is. A lot of people who get sick can pinpoint for you the moment it started. There aren't a lot of things that feel like that. If you have diarrhea or vomiting or nausea, you probably have some other virus.
Is our disaster-preparedness in better shape now than it was a few years back, when SARS or the bird flu was in the news?
In some ways, yes. We've done a lot of planning, and we have stockpiles of anti-virals that can treat the disease and prevent it in people who have been exposed. On the other hand, we don't have a vaccine. Without a vaccine, you've got one hand tied behind your back, at least.
We've been looking at ways to speed up our vaccine-production system, so that you could have vaccine in a couple of months or a month instead of nine months. We have the technology to do that. But the profit margin for a pharmaceutical company on a lot of vaccines, flu vaccine in particular, is minimal. There are a lot of other issues, as well-we don't have a good distribution system, for instance.
It requires a coordinated effort from four different groups in order to solve this-industry, academia, government, and public health. But it's important to do that. If you strengthen our regular vaccine system, it would be more robust when something like this happens.
Going back to people's fears about what may develop—what ages seem to be particularly vulnerable to swine flu?
We're seeing the typical pattern—the young, the old, the immune-compromised. There will be disease in young, healthy people, though, and maybe more than usual. That's because nobody has any kind of immunological history with this virus. But the virulence and the potential to kill don't seem to be greater than what we normally see.
This morning, Dr. Currie gave this update:
We had a meeting this morning where we looked at the volumes of people presenting to emergency rooms and such. The numbers of symptomatic patients are doubling, but the number of people who actually have the flu remains low. That's good news, but the worry about swine flu is creating a stress on the system.
Something to remember is that if symptoms wouldn't have sent you to the doctor before you'd heard of swine flu, they shouldn't send you to the doctor now. And if you go to the doctor, don't expect that you're necessarily going to be treated or admitted. If you're young and healthy and you're weathering the infection all right, the recommendation is just to go home.
And stay home?
Yes! And stay home.