Measles in the United States
Although Ebola seems like a looming threat, a subtle, more contagious threat is rising. Measles spreads easily through saliva or aresols. In 2014, there has been 592 cases of measles in the United States, part of 18 outbreaks in 21 states-- almost three times the less than 200 cases of measles in the US in 2013. This is particularly troubling, because measles is the fastest spreading disease in human history—each infected person induced 17 secondary cases in the era before comprehensive vaccines and 3 out of 4 infected died. For comparison in the 1918 Spanish Influenza of 1918, each infected person induced only 2-5 secondary cases.
Why this sudden spike in cases? In 1963, comprehensive vaccination for measles became standard and the disease was declared eliminated in the United States in 2000. Two doses of the measles vaccine proves to be ninety-nine percent effective at preventing measles. Forty-eight states allow for exemptions in vaccines based on personal beliefs (excluding West Virginia and Mississippi). California allows for a Personal Belief Exemption. In Marin country, where many of the cases in the 2008 measles outbreak occurred, only 83.5% of school children had completed their required vaccinations. 2/3 of cases of measles in the first 9 months of 2013 occurred in “pockets” of unvaccinated populations.
Measles cases typically enter the United States from international travel, but due to the contagious nature of the disease, any one who is not vaccinated is at risk to catch measles. If the anti-vaccination movement continues to gain traction, diseases like measles, mumps, and rubella may not longer be mostly “eradicated” and become a major public health threat.