On October 1 2007 a case of Measles was confirmed in Ann Arbor Michigan
For most of us, it's been a long time since we've thought about the measles. As a refresher, measles is one of the most contagious infectious diseases. The measles virus causes a distinct clinical syndrome characterized by fever, watery eyes, runny nose, cough, rash and white "Koplick's" spots in the mouth. Measles occurs throughout the world, and was once considered "as inevitable as death and taxes". The overall complication rate in measles is about 25% and often results in hospitalization and in some cases death.
Due to its highly contagious nature and severity, children are routinely vaccinated against the measles in the United States. The recommendation is for one dose of MMR (mumps/measles/rubella) at age 12 to 15 months and a second dose at age 4. This provides long-term immunity against the disease. Prior to the availability of the safe and effective measles vaccine in 1963, the number of cases in the United States was between 500,000 and 1,000,000 per year. In the prevaccine era, 90 percent or more of children developed measles by age 15.
What is puzzling is how, in the era of measles vaccination, did a youngster from Ann Arbor ever get the measles? This is the Big Question. The child must have been exposed to someone contagious. Every year there are millions of cases of measles worldwide. Travel to Europe may have been the exposure link in this child. On 9/28/07, the Evening Standard U.K. reported that "Measles is soaring across London," with a citywide warning that an outbreak could spread "like wildfire" because immunization rates are so low. Part of the problem in London is that only half of children have been fully immunized against the measles. Measles is still an ongoing and active disease. In 1995 there were 44 million cases of measles with 1.1 million deaths due to the disease worldwide. In the United States, where most children are vaccinated, fewer than 100 cases of measles have been reported annually in recent years. Good job US!
But, if the youngster was vaccinated, how exactly did he/she get the measles??? This is where it gets a little confusing. In a very large majority of children the vaccine provides perfect protection, but in a very small number of children, the vaccine provides a little less than 100% protection. In these few children, a 'mild' case of the measles can develop. This appears to be the case in the Ann Arbor youngster. Fortunately the child will probably have a mild or 'modified' case. Unfortunately, the child was contagious for a period of time, which puts others at risk. The risk is greatest for the 20 schoolmates who have not been immunized. These children have been advised not to attend school to avoid exposure and the potential serious complications of the full measles disease.
Details and updates can be found at www.ewashtenaw.org, The Washtenaw County web site.