The consequences of mumps

Mumps was a common childhood disease when I was a child. We grew up learning that it was better to get mumps as a child because getting it as an adult would make you sterile. No doubt that idea arose from symptoms like swollen glands, swollen testicles, etc. When I looked in PubMed though, I couldn't find much data on sterility (at least not easily). I did find data on hearing loss. Death is not a common outcome of mumps. Between 1953 and 1962, there were 162,344 cases of mumps in the U.S. every year and only 39 deaths per year. People, mostly children, did die from mumps, but other diseases had higher fatality rates. In 2004, there were no cases and no deaths. For some reason 2006 was strange. There was an outbreak among unvaccinated people with 6584 cases (1). Nobody died that year although 85 had to be hospitalized (2). Why do we vaccinate children to protect them against mumps? With less than a hundred deaths per year, why do we care? The argument could be made that preventing even a few deaths is worthwhile. I'm sure the parents of the lost children would have rather had the vaccine. The argument can also be made that it's a good thing to prevent hearing loss. Deafness was a well-known consequence of a mumps infection. It's not lethal, but neither is it easy. How much of a problem is this? We can learn from the other countries who have unintentionally done the experiment. In Japan, mumps vaccines are more optional than they are in the U.S. or Canada. This means that are larger groups of children who haven't been vaccinated. Their experience can teach us what happens when we don't vaccinate against this disease. The Acute Profound Deafness Research Committee of the Japanese Ministry of Health wanted to know what happens to children who don't get vaccinated. They studied reports from three years; 1987, 1993, and 2001 and found 300, 400, and 650 cases of mumps-related deafness (3). They also reported that the hearing loss was often permanent. Reference:

1. Sandra W. Roush, MT, MPH; Trudy V. Murphy, MD; and the Vaccine-Preventable Disease Table Working Group 2007. "Historical Comparisons of Morbidity and Mortality for Vaccine-Preventable Diseases in the United States" JAMA 298:2155-2163.
2. Dayan, G. et. al. 2008. Recent Resurgence of Mumps in the United States. NEJM Volume 358:1580-1589.
3. Kawashima Y, Ihara K, Nakamura M, Nakashima T, Fukuda S, Kitamura K. 2005. Epidemiological study of mumps deafness in Japan. Auris Nasus Larynx. 2005 Jun;32(2):125-8.

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