A conversation with Dr. Paul Byers on current flu season
Flu season is upon us, and with it the fear that possible infection lies behind every cough, sneeze or handshake. Dr. Paul Byers, the state epidemiologist with the Mississippi State Department of Health, recently spoke with the Sun about the season. Byers is a graduate of Millsaps College and the University of Mississippi Medical Center and has been epidemiologist for four years.
Is this going to be a bad flu season, a mild one, what?
“That’s a great question. It’s very difficult to predict how flu seasons are going to be. We know we’re in the middle of it right now. So far, it does not seem to be as significant a season as last year, although we’re uncertain how much more of the season we may have left, and if we may see some worsening. Any flu season can be significant, even when it’s classified as mild, in most season, influenza-related deaths occur, and influenza-related hospitalizations and complications can occur. Overall, a season may be less severe, but for those who get sick, it can be very severe.”
Why is it so difficult to predict a season’s severity?
“A lot of factors go into trying to determine, even after the fact, how severe a season may have been. It may have to do with the type of virus circulating during the season. In a normal season, there’s usually just one predominant strain – that predominant strain can influence the severity of a season. Some types of influenza A have a greater impact on elder and those with chronic medical problems. When we have that type, it can really lead to some increase in severity. Some seasons, like this season, so far the predominant strain has been influenza B.”
“It can be determined on how good of a match the vaccine is to the circulating viruses. Sometimes, when the vaccine virus is not as effective as preventing illness and complications, and it may be more severe. When you look at severity, you also have to look at how many pediatric deaths there have been, how many hospitalizations there have been, the overall influenza rate for the U.S. Also, it’s hard to tell how long the flu season may be, until you get past it.”
When does flu season typically run?
“Usually we think of flu and we ramp up our surveillance in October. For the typical season, it can usually run from October to May. But when you do actually see flu activity, in most seasons, you see peak activity somewhere in late December, and sometimes into late January and February. It (the peak) can occur much earlier and can occur much later. We’ve had seasons that may not see the peak until March or later. You don’t want to guess when you need to get the flu shot. You want to go ahead, if you haven’t gotten it, it’s not too late. We may not be at peak activity yet.”
You mention the surveillance that’s done and the data that’s gathered. How do you gather it?
“Individual cases are not reportable. What we do, and this is how other states do it, we have identified providers throughout the state – primary care providers, family doctors, pediatricians, health centers, emergency departments – they report to us each week the total number of people they see in their clinics and the total number who have an illness consistent with the flu. This is how we calculate our influenza rate each week. This is what we report to the CDC. This is not every doctor’s office that reports but selected (offices) throughout the state. This is not complete reporting but it gives us an estimate on our flu activity based on our selected providers.”
How many providers do you have?
“We have in the range of 50 providers that report to us.”
So far this year how many cases have there been?
“It’s difficult to say how many cases we’ve had to date. One thing to note is that the CDC has published some estimates for what they expect the total number of flu cases to have been in the U.S. so far – they say it’s been over six million so far in the U.S.”
Is that a typical number?
“So far it’s been a milder season. There have been fewer pediatric deaths than in the last couple of years, but we’re still very young in the season potentially. We could have several more weeks before we’re through. It’s too early to say whether we’ve reached peak activity. Although it seems milder, there’s no guarantee that it will stay that way.
You mention the flu shot and how the virus might not match the predominant strain. How is the virus used in the flu vaccine determined?
“In most vaccines, it’s protective against four different strains. There is another type of vaccine that is protective against three different strains. Each year at the end of the season, the CDC looks at the type of influenza that causes influence in the southern hemisphere. That’s a good indicator of what would cause (flu) in the U.S., because their season is opposite ours. Also, the CDC looks at the flu types that caused infection in the U.S. and makes a determination of what are going to be the potential types of virus that could cause illness next season. That is what the vaccine is directed against.”
So, what’s going on in South America during their flu season could be the flu we have next year?
“It sure could, and that’s been shown before. What we’ve seen in the past years is if Australia is really having a severe season, we may be about to have one.”
How effective is this year’s flu shot?
“It’s a bit early to determine the true effectiveness of the shot yet. Typically, the CDC will release some mid-season estimates on vaccine effectiveness. Those should be coming out soon. One of the big things about the flu vaccine is that even under the best of circumstances, people can get the vaccine and end up getting the flu. Sometimes, (the vaccine) is not the best at preventing infection, but the benefit is shown that if you get the flu and you’ve had the shot, it is much less severe. There’s less chance of having hospitalizations, less chance of complications and less chance of having a death as a result if you’ve been vaccinated. And you’re less likely to spread it as well.”
One thing that we’ve noticed is there always seems to be a shortage of Tamiflu. Why is that?
“It’s been our experience, there have been some reported difficulties in getting Tamiflu in the past that have been primarily in individualized locations. There is plenty of supply to get, but they have run into shortages in very localized areas. From a national perspective, there are not expected to be Tamiflu shortages.”
How many deaths have occurred so far this year from the flu?
“The CDC estimated there have been 2,900 deaths nationally. Again, it’s too early to get an idea of the individual deaths in Mississippi. Again, those are not reportable. What’s reportable in Mississippi are pediatric influenza deaths. So far this year, we’ve had no pediatric deaths. We hope to continue that. That’s a tragedy we’d prefer not to have in Mississippi.”
What are some preventative measures people can take to avoid the flu?
“First and foremost, anyone six months or older should get a flu vaccination every year. It’s better to get it earlier rather than later. Don’t wait until the middle of the season. It takes a couple of weeks to get the appropriate immunity after being vaccinated. It’s especially important for people of high risk – those over 65, children under 18, children especially under five. Those are the ones we see for the highest risk of complications. The vaccine can prevent those vaccinations.
“There are other things you can do, but they are good things for any illness. Star with handwashing. Make sure you cover your coughs and sneezes. If you think you have the flu, don’t go to work because you can spread it. If you think your kids have it, don’t take them to school. We know schools are a hotbed, where kids share everything. You don’t want your child to be the cause of illness in somebody else. If you get the flu, talk to your doctor about Tamiflu.”
Everyone remembers the H1N1 virus and the Spanish flu epidemic that occurred in the early 1900s. Are there chances another pandemic could occur?
“It’s always a possibility. That’s one of the reasons we do surveillance. That’s one of the reasons we look for the types of viruses causing illness – it’s a way to detect new strains that pop up that nobody has immunity to. That’s what we saw in 2009, when we had the H1N1 epidemic. (The virus was) was easily transmitted and no one had any immunity to it. Those are the primary criteria that must be met for us to be concerned about a virus – a new virus, that is easily transmitted from person to person, and nobody has any immunity. That’s a recipe for pandemics.”