Measles Outbreak in Minnesota Linked to Drop in Vaccination Rates

As Minnesota battles its largest measles outbreak in decades, state health officials have linked the recent spike in cases to a sharp decline in vaccination rates in a local Somali community.

The highly-contagious measles virus is marked by very high fever and a telltale rash of flat, red spots that begin on the face and spread down throughout the body. According the Centers for Disease Control and Prevention (CDC), the introduction of the measles, mumps, and rubella (MMR) vaccine in 1963 has led to a more than 99% reduction in the number of measles cases annually in the United States. Prior to widespread vaccination, the United States saw 3 to 4 million cases each year. People who have not received the MMR vaccine may be vulnerable to catching measles when travelling abroad, and US communities with low vaccination rates lack the “herd immunity” to prevent an outbreak if they become exposed to the virus.

According to officials with the Minnesota Department of Health (MDH), the state has seen 48 measles cases as of May 9, in an outbreak they’ve been tracking since April 11. Of those infected, 41 individuals are members of a Somali community in the state, and 45 individuals have not received the MMR vaccine, while 2 individuals received two MMR doses, and 1 received 1 dose. The outbreak has included 46 children and 2 adults. This is Minnesota’s biggest outbreak in more than two decades, marking the highest number of measles cases seen in the state in a single year; the state has seen a total of 56 cases, either imported cases or linked to imported cases, in the last 20 years combined.

Minnesota health officials are investigating the outbreak, which has spanned over 3 counties (Hennepin, Ramsey and Crow Wing). Recent cases have been linked to the potential influence that the anti-vaccination movement has had on the local Somali immigration community. A recent article in the Washington Post reported that members of the Somali community were advised by members of the anti-vaccine movement to not let their children receive the MMR vaccine due to the discredited theory that the shot causes autism. State health experts, though, are emphasizing that the current outbreak is in no way endemic to the immigrant community and that children across the state who have not received the MMR vaccine are vulnerable to the virus, if exposed.

“This is about unvaccinated children, not specific communities,” said Minnesota Health Commissioner Ed Ehlinger, MD, MSPH, in a recent statement. “There are people of all backgrounds around the state who have chosen not to protect themselves or their children. Often, that decision is based on good intentions and inaccurate information. It’s the responsibility of all of us who care about the health of Minnesota children to make sure people have accurate information and take action to protect their families and their communities.”

The CDC notes that two doses of the MMR vaccine are 97% effective at preventing measles infection, while one dose is 93% effective. In Minnesota, the MDH is recommending that all unvaccinated children 12 months and older and all unvaccinated adults born after 1957 receive their first dose of the vaccine as soon as possible. For children living in affected counties or those in the Somali community who have only received one dose, health officials are urging parents to ensure their children receive the second dose as soon as possible to prevent further spread of the virus.