Already this year, there have been 1,881 reports of whooping cough in Minnesota. That's more cases than any other full year since 1947.
Whooping cough, also called pertussis, is increasing nationwide. About 18,000 cases have been reported by the Centers for Disease Control and Prevention across the country.
MPR's medical analyst Dr. Jon Hallberg discussed the rising rate of whooping cough with Tom Crann of All Things Considered on Tuesday. Hallberg is a physician in family medicine at the University of Minnesota and medical director of the Mill City Clinic.
An edited transcript of that interview is below.
Dr. Jon Hallberg: This is a toxin that actually causes the disease. But whooping cough is sort of the clinical picture, the thing you see and hear.
Tom Crann: Why is it called whooping cough?
Hallberg: It really has to do with the sound that infants and those that are very small and tiny make. They'll have a paroxysm, or a spasm of coughing, a coughing jag, and then they'll try to catch their breath. And as they inhale there's this characteristic whooping sound. You typically don't hear it in older children or adults.
Crann: It sounds like it's more dangerous for young children than it is for adults?
Hallberg: Basically that's because infants have teeny, tiny bronchial tubes. And swelling there is going to have a much greater impact than swelling in our bronchial tubes as we get sick.
Crann: What is the common treatment for it?
Hallberg: Luckily, you can use antibiotics.... Which one you give depends a little bit on the age of the person who's infected, but it is very effective.
Crann: If someone has a persistent cough, what's the difference? How do you know whether it's whooping cough or maybe bronchitis or pneumonia?
Hallberg: That's the trick, because when pertussis infection starts it looks like a cold. It takes a good week or two probably before you know that you're dealing with whooping cough.
This is really a challenge and national public health authorities are saying, get people started on antibiotics very soon because if you miss this two-week window, then antibiotics aren't effective. You have to get it soon, but at the same time, in clinic, we're very cautious about overprescribing antibiotics. It's a bit of a conundrum we're in right now.
Crann: Most of us have been vaccinated for this in childhood, and even in adult booster shots sometimes. Why is it on the rise?
Hallberg: It's a great question and we don't know why. It does not seem to be that people are not getting the shots as infants, they're getting the shots. It could be that the bacteria has evolved in a way and isn't kept in check with the shots we've got.
It could be that we're detecting more of it because we have a nasal swab that we use to detect the presence of this bacteria.
A really interesting theory is that in the late 1990s, we knew that pertussis immunization could give kids a high fever. By adjusting the way we put the vaccine together... that may have rendered the immunization less effective. We're not seeing the fevers anymore, so maybe it's not as immunogenic. It's not providing us the long-lasting immunity we once had.
Crann: If people hear this and they're worried, should people just run off to their doctor and get vaccinated?
Hallberg: Yes, we're actually saying come and get it. The CDC is actually recommending this. There's been a lot of changes over the last five, six, seven years over what the recommendations actually are. But basically any adult can get this if they haven't had it yet.
Interview transcribed and edited by Jon Collins, MPR reporter.