Officials have been warning a measles outbreak could be ahead in Wisconsin. Now it's here, mainly in the southwestern part of the state. As of Sept. 2, there were 110 confirmed cases statewide. All but one of those sickened are unvaccinated.
WUWM's Maayan Silver asked Dr. Ben Weston, chief health policy advisor for Milwaukee County, about the outbreak.
This interview has been edited for length and clarity.
Maayan Silver: This Wisconsin outbreak is part of about 3,000 recorded cases nationwide. And it's the state's most severe since 1990, according to the Milwaukee Journal Sentinel. Can you explain why measles cases are rising in the U.S.?
Dr. Ben Weston: Yeah, I mean, here in Wisconsin, we have the second-lowest vaccination rate in the nation. We're only behind Idaho, and that is not a good place to be. It really makes us just highly vulnerable for outbreaks like this.
So in Wisconsin about 85% of kindergartners, that's one of the standard metrics, 85% of kindergarteners are vaccinated. In these counties we're looking at: Grant, Iowa, Lafayette, they get as low as 60% vaccination rates, which just isn't nearly high enough to protect the population. You need really well over 90% to get that herd immunity, where people are protected, including people who are immunocompromised or too young to get the vaccine, for example.
Note: "Herd immunity" is when enough people in an area have immunity to (protection from) a disease that it no longer spreads easily. It usually takes a large number of people getting vaccinated against or infected with the germ to achieve herd immunity.
Do we have any information as to how the Wisconsin outbreak started?
We don't have specific information there. Typically, all you need is one case, because measles is so incredibly contagious that one person can spread it to nine to 10 unvaccinated people, which is just a really high spread rate. And so you can see when you have those low vaccination rates, it spreads incredibly fast. So Wisconsin really is just this tinderbox set up for an outbreak.
Are you hearing from your partners in public health in Grant, Iowa and Lafayette counties about how they're approaching this on the ground?
Yeah, I mean, I think there's the standard public health approach, which is number one, you want to track these cases. You want to put up barriers as much as you can to protect people who surround these individuals. Of course, you want keep them isolated from others so they don't spread it.
This gets back to kind of our COVID days. But a big part of it is prevention into the future. So for parents across Wisconsin, I know there's a lot of mixed information out there right about measles, about vaccination in general. So if you have questions, that's OK. If you're not sure, that is OK, but this is a really good time to reach out to somebody you trust, probably your physician, your family doctor, your pediatrician who you've trusted for everything else that your kid and your family has gone through, and ask them. Ask them their opinion on whether you should get vaccinated, because this is a great time to get protected. Because I would imagine these cases are going to increase just based on the number that we're seeing. And with the vaccination rate in our state, it would be very surprising if we don't see these numbers continue to increase.
And you mentioned that measles is highly contagious. What are some of the health complications that can be caused by measles?
For a lot of people with measles, you get typical febrile illness, you get fevers, you feel run-down, you might get respiratory symptoms, but the problem becomes that for a certain percentage of people, they can get really sick. And that's why you've seen two out of these 100 folks, 110 in Wisconsin, have been hospitalized. About one out of 1,000 have further complications, things like brain swelling and even hospitalization that leads to death. And that's why as the numbers get higher and higher, and we see almost 3,000 cases nationally, those small percentages become much greater.
And unfortunately, most of the time, these are young kids who are getting this just because of how quickly measles can spread in communities and especially in settings like schools. So you want to make sure yourself, your family, your kids are as protected as they can be. And luckily there's an easy way to do that. It's with a vaccine that's been proven safe and effective over decades. Not just a couple years here, but over decades, it's been proven safe and nearly 100% effective with two shots.
Two doses of the vaccine provides that protection that you're talking about against all strains of measles. What happens if you get vaccinated and then get measles?
That's a good question. So the reason for the herd immunity is because every once in a while there's somebody who gets vaccinated and it's not quite 100%. So some people slip through those cracks, whether it's because they're immunocompromised or their immune system just didn't respond in the way that we anticipated. So certainly that does happen. That's why 109 out of those 110 people were unvaccinated. One of them was, it seems, vaccinated.
Now, when you are vaccinated, what the studies show is that you are much more protected against getting severe disease. But nonetheless, there are people out there who despite getting vaccinated, they still have an immune system that just doesn't work very well, or they're very young, or they are very old, or they have other health complications. And so that's why it's important to get vaccinated. This is kind of the social contract that we go into. You get vaccinated for yourself, but you're also getting vaccinated for your community.
