With 39 confirmed cases as of Friday, Michigan is currently experiencing its worst measles outbreak since 1991. All but one of the infections reported has been in Oakland County, where the outbreak likely began when a traveler from New York City contracted the disease and brought it to Michigan during March 6-13. The Oakland County Health Division has responded by creating a list of possible exposure sites and opening vaccination clinics, but the county’s relatively high vaccine waiver rate of 4.8 percent causes concern for health officials who worry that the outbreak could continue to spread.
Michigan is not the only state where measles is a growing problem. Infection rates have been on the rise in the whole country in recent years, and outbreaks have been reported in New York, Washington, Texas, Illinois and California. Because the virus can survive in the air for up to two hours and has an incubation period of 21 days, measles is a highly contagious disease. Unvaccinated individuals have a 95 percent chance of contracting it if they are exposed, as Medical Director for the Oakland County Health Division Dr. Russell Faust told Michigan Radio. The CDC reports that two doses of the measles mumps rubella (MMR) vaccine is 97 percent effective against measles, but in counties like Oakfield, vaccination rates have dropped below what is necessary to maintain herd immunity. Michigan is one of 17 states that allows parents to choose not to have their children vaccinated, and the statewide vaccine waiver rate stands at around 2.4 percent. This might seem low, but certain counties, including Oakland, have significantly higher waiver rates. Communities where vaccine rates are lower have a heightened risk of experiencing measles outbreaks.
Health officials are concerned about measles not just because the disease is so contagious, but also because it carries the risk of serious complications. In addition to the fever, cough and rash usually associated with measles, the CDC explains that about one in 20 children with measles will contract pneumonia and one in 1,000 will develop potentially fatal brain swelling. Infants, pregnant women and people with a weak immune system are especially vulnerable. Fortunately, the Mayo Clinic says that those who might be at risk can be vaccinated up to 72 hours after.