Last Updated: July 21, 2009
As the H1N1 ("swine flu") virus has made its way across the world, so has misinformation and confusion about what the virus is and what sort of threat it poses. This holds particularly true for people with weakened immune systems or some people living with HIV. To help us fill in that knowledge gap, we've asked Dr. Joel Gallant for some insights. Dr. Gallant is a professor of medicine and epidemiology in the Division of Infectious Diseases at the Johns Hopkins University School of Medicine and he happens to be one of the leading HIV specialists in the United States.
Dr. Gallant, thank you very much for talking with us.
Thank you, Myles. My pleasure.
Let's start with the basics. What is swine flu?
Swine flu is just a new strain of flu that has not been circulating in the population. As a result, nobody has any immunity to it. It's an influenza virus, just like other influenza viruses, but it's just one that human beings haven't seen before and as a result, our immune systems don't have any memory of it and that makes us a little more vulnerable.
When it comes to people living with HIV then, how does this translate? Are people with HIV more at risk for coming down with swine flu?
Not really. HIV-infected people are not in general at greater risk of influenza or flu than other people. And that's in part because the cellular immune system, the part of the immune system that the CD4 cells comprise, is not really responsible for fighting the flu. As a result, HIV doesn't make you more susceptible. For most people with HIV, the swine flu is pretty much the same as it would be with somebody without HIV.
The only exception to that is that because people with HIV are at higher risk for pneumonia and because flu can increase your risk of pneumonia as a complication of flu, people with low CD4 cells could be at higher risk of complications of flu if they do get the flu and that the most important complication is pneumonia.
So the bottom line is that if you're HIV positive, but you're on HIV medications and doing well and have a reasonably good CD4, then there's probably not much to worry about. But if you're quite immunosuppressed -- if your CD4 is well below 200 -- then there is a slightly increased risk, but certainly not the same level as the risk of some other diseases like tuberculosis or something like that where the CD4 cells are so important.
It sounds like people with HIV have a greater risk not of getting swine flu necessarily, but of suffering complications related to it if they have a low CD4 count.
That's right, yes. The risk of getting the flu is the same.
I'm assuming viral load doesn't make a difference here.
Probably not much. Again, the viral load could contribute a little bit to the risk of complicated flu, if you had a high viral load. Although, I suspect the CD4 count would be a little more important.
What Can I Do to Protect Myself From Getting Sick From Swine Flu?
There are everyday actions that can help prevent the spread of germs that cause respiratory illnesses like influenza. Take these everyday steps to protect your health:
From the U.S. Centers for Disease Control and Prevention
For more information on swine flu, visit TheBody.com's collection of articles on swine flu.
Certainly at our clinic [Moore Clinic in Maryland -- click here for contact information] we try to vaccinate everybody against the flu, but in general, if you look at most influenza seasons, we really don't see a lot of people getting really sick from the flu. We don't really see a lot of need for hospitalization. And certainly, we don't see a lot of deaths.
So I think that with respect to the swine flu, it shouldn't be much different given what we know so far about this strain now. Although, again, this is a new epidemic and we may get more information as time moves along.
Are there any precautions HIV-positive people need to take to protect themselves from swine flu?
It's pretty much the same as for anyone else. Normally I would say get a vaccination, but that's not available yet for this strain of flu, so the next best thing you can do is:
But short of that, there's not really much you could do.
You said there's no vaccination for this flu. But what if someone got vaccinated for the flu before the winter -- will that do anything to protect them from swine flu?
No, unfortunately it won't. The vaccine for this last winter's flu covered flu strains that are not the same as this swine flu and it would not provide protection.
Alright, so that flu bird has flown?
Yes, exactly. They are trying to come up with a vaccine for this one, but that wouldn't be available for some time.
If a person were to come down with swine flu, what are the treatments that are typically available?
There are actually a number of drugs that are active against various strains of flu. The ones that are most widely used are Tamiflu [oseltamivir], which is a pill, and then Relenza [zanamivir], which is an inhalation. Both of them are effective against this strain of flu, so if you were to come down with symptoms, then it would be important to try to get this medication and start taking it relatively soon. You don't want to wait too long or it ceases to be effective.
Remember that a lot of people will refer to cold symptoms as a flu, but it's important to distinguish between a common cold and a flu. Flu is something where you have pretty significant fever and muscle aches and fatigue before you actually get respiratory symptoms. So it's not like a cold where you get a sore throat and then maybe you feel sick a day or two later. With swine flu you really can all of a sudden feel really wiped out with muscle aches and fever and that would be a time when you'd want to start taking medication.
Do you know how readily available Tamiflu or Relenza are?
I have not heard of any shortages at the present time. I'm told that there are big stockpiles and that there is enough Tamiflu to go around, that it's being shipped out to states that are reporting flu cases, so I haven't heard. There's certainly no reason to rush out and try to stockpile it. It is available.
Is this the sort of thing that is typically covered by private health insurance, Medicare, ADAPs [AIDS Drug Assistance Programs]?
It's covered by private health insurance. I'm not aware of whether it's on ADAP formularies. I sort of doubt it, although perhaps some states would have it. That's a state-by-state issue.
Can Tamiflu or Relenza potentially interact with HIV medications or with the medications used to treat infections, such as pneumonia?
No, the drug can be used with antiretrovirals. There are no significant drug interactions. It can be used with the drugs we commonly use to treat or prevent pneumonia. So that really should not be a concern, but do keep in mind that if you were to develop flu and then develop pneumonia -- of course by then, I hope you would be under the care of a doctor -- that Bactrim [co-trimoxazole] may not be the right drug. So Bactrim's a good drug for pneumocystis, but not a great drug for the types of pneumonia that might complicate flu.
Alright, well is there anything else that you'd want to tell HIV-positive people listening to the swine flu craziness that's now overwhelming the news?
For the most part, I've been reassuring my patients that they don't really have to think about this flu differently than anyone else. And that's in part because most of my patients are on HIV treatment and have undetectable viral loads and have decent CD4 counts. So for them, it really is not a special issue. It's an issue we all have to be concerned about.
So no need to panic?
No, definitely not. I mean so far this doesn't look like the kind of SARS [severe acute respiratory syndrome] or avian flu sort of pandemic that we have been worried about in recent years.
If I had to bet, I would say that this will end up being perhaps a big epidemic in numbers, but not too much worse than just a regular old flu season except that it's happening at the wrong time of year. That's what I hope we'll see, but like I said, we'll have to just see what happens as the data emerge.
I guess we'll stay tuned. I have saved the most important question for last, which is: Is it not true, sir, that you are most likely to get swine flu if you eat pork that's been imported from Mexico?
[laughs] No, you're not going to get it from eating the pig. Maybe if you're raising the pig, that might be different, but it's OK to eat it.
Dr. Gallant, thank you so much for taking the time to talk with us.
This transcript has been lightly edited for clarity.