Lessons From Largest Measles Outbreak In Minneapolis Since 1990

posted by AHIP

on August 21, 2017

A measles outbreak that sickened Somali-American children in Minneapolis has reinforced the importance of getting vaccinated, and the role collaboration and community trust played in stopping the virus from spreading.

“I was expecting several hundred cases. The susceptible population was there; but with all the coordinated effort, it was limited to 79 cases,” said Dr. James Nordin of HealthPartners in Minnesota, an AHIP member.

Dr. Nordin spoke with AHIP about identifying, tracking, and controlling the spread of an extremely contagious disease like measles, as well as about the outbreak’s effect on immunization rates and perception of immunizations among Minnesota’s Somali community.

Describe the Spring 2017 measles outbreak in Minnesota. How did it occur and how many people were affected?

Dr. Nordin: It occurred over a few months in Hennepin County, where Minneapolis is located, and surrounding areas. The outbreak was focused in the Somali population. Measles is endemic in Somalia. There are people traveling back and forth, so it was probably introduced to Minnesota by someone traveling back from Somalia, although the index case was not identified.

Another key factor is that immunization rates were very low within the Somali community. Right before the outbreak, the rate of two-year-olds who had received the Measles Mumps Rubella (MMR) vaccine (routinely given at age 1) was 40 percent among the Somali children. In 2004, it was 94 percent among the Somali population.

Why did vaccination rates drop so dramatically over this time?

Dr. Nordin: Most of that drop happened in the last four or five years, due to a couple things that happened. One is that the schools were diagnosing a lot of autism in Somali children here.  An early study showed that autism was higher among Somali kids than other kids in the community.  A later study showed the rate was equal in both groups, though still fairly high.

The second big factor was that Andrew Wakefield, who published the now infamous Lancet article in 1998, spent quite a bit of time in the area working to convince Somali elders that the MMR vaccine was the cause of autism – despite the fact that his study has been found to be bogus.

I have a lot of Somali patients, and when I presented the idea of MMR to parents, the consistent response was that the vaccine made kids stop talking, and they did not want it for their kids.

You mentioned the children affected. Were any adults affected?

Dr. Nordin: The outbreak saw 74 cases in kids and five cases in adults. From a race/ethnicity perspective, 64 were Somali Minnesotan, 11 white non-Hispanic, three white Hispanic, and one black non-Hispanic.  The outbreak was centered in two daycare centers in Minneapolis, but it went other places too. About 20 of the kids were hospitalized.

What efforts were taken to control the outbreak?

Dr. Nordin: A well-respected Somali doctor in the community really got out and pushed that these kids needed to be immunized and that the MMR was not causing autism.

I was expecting hundreds of cases, but the lessons learned from the outbreak 25 years ago led to two key actions. First was the education aspect, from the Somali doctor and other respected individuals within the community, and from the state and local health departments. Second, tracing those who had been in contact with infected individuals was very important to controlling spread. This was done by the local health departments, the Minnesota Department of Health, clinics, and the two children’s hospitals where there had been lot of exposure. The fact that the contact tracing was a coordinated effort by the whole medical community was very beneficial.

All in all, about 8500 contacts of people who had had measles were traced, immunization records were found, and those people with no history of MMR immunization were then immunized if it was done within 72 hours of the exposure. Immune globulin was given for exposure more than 3 days previously. Immune globulin provides immediate, short-term protection against measles when given within six days after exposure.

The rate of administration of MMR in Somali children in Minnesota was about 40 per month before the outbreak. Since then, it’s been about 400 per month; there is a lot of immunization happening. In my clinic, the rate of MMR immunization the year before the outbreak was 35 percent by age 2 in Somali children and it was probably dropping –   that changed with the outbreak.

Attitudes changed. I had an interesting conversation with a Somali mother about MMR. She said she didn’t like MMR. I replied that she probably didn’t want her kid to get measles either and she agreed – so the child was immunized. Since the outbreak about two-thirds of the Somali children coming in to my clinic who were not previously immunized have been immunized.

How long did it take to control the outbreak?

Dr. Nordin: It took about 4 months.

That seems like a fast response.

Dr. Nordin: It was – I know the state health department spent about $350,000 on personnel in combating the outbreak. The local health departments, and the children’s hospitals spent a great deal of time, energy, and money. Several HealthPartners clinics had measles in them, so everyone who had been in the clinic within two hours of the measles case was contacted. The entire medical community took this approach.

There was a great deal of coordination. The Minnesota Department of Health laid out appropriate policy for the hospitals and clinics, and they tracked down people who had been exposed in their facilities. Then the Minnesota Department of Health and the local health departments talked to people who had measles and tracked down other contact points beyond the hospitals and clinics, like the daycare centers. It was a coordinated effort across the entire medical community.

What lessons can we learn from this?

Dr. Nordin: The Minnesota Department of Health has always been strong regarding cooperation, but this took it to the next level. It was a coordinated medical community-wide effort.  A coordinated education campaign was also crucial.

In 1990-91, we had a major measles outbreak in the Twin Cities centered in a newly immigrated group, the Hmong community. There were 453 reported cases and three deaths in young, healthy children. A lot of the people who worked on the 2017 outbreak were around then and we learned from it.

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