According to the Department of Public Health, the US is experiencing a significant increase in the number of cases of Measles this year with 187 cases reported from 1/1 /2014 to 5/9/2014.
But I thought Measles was eliminated. How is this happening?
Measles has been considered eliminated from the US since 2000, but continues to be a significant public health issue worldwide. The CDC actually estimates that world-wide in 2008 there were a horrifying 450 deaths every day as a result of infection with this vaccine preventable illness. Prior to widespread immunization in the US 3-4 million people were infected and 4-500 died from measles every year. Widespread use of measles vaccine has led to a greater than 99% reduction in measles cases in the United States compared with the pre-vaccine era, and in 2012, only 55 cases of measles were reported in the United States.
The current outbreaks of measles are “imported” from other countries, but transmission occurs in vulnerable populations with outbreaks more likely when infection occurs among groups of people with lower rates of immunity from the disease. For example a single community in Texas with objections to vaccination accounted for 59 of 157 cases reported in 2013. Measles isn’t really “back,” but this hinges on continued widespread public participation in measles vaccination.
The local outbreaks of measles in specific unimmunized populations are an illustration of how vaccination prevents outbreaks and saves lives. When a critical portion of a community or group is immunized against a contagious disease, all members of the community are protected against that disease because there is little opportunity for an outbreak. Even those who are not eligible for vaccines—such as infants, pregnant women, or immunocompromised individuals are protected because the spread of disease is contained. This is known as “herd immunity.”
The proportion of people who need to be vaccinated to achieve herd immunity depends on how contagious an illness is. Measles is not only the most frequently fatal of the childhood viral illnesses, it is extremely contagious.
Statistical estimates of how many people in a community need to be vaccinated to achieve herd immunity from Measles range from 92-95%.
With the elimination of Measles we have lost some of our collective memory of it’s impact while the potential hazards of vaccination seem larger than they are. Happily, there is overwhelming evidence that vaccination is safe and effective. Even in the US, where many illnesses have been reduced or eliminated thorough widespread vaccination, individuals are roughly 1000 times more likely to suffer a significant complication from a vaccine preventable illness than suffer significant harm from the vaccine itself.
Help keep everyone, and especially yourself healthy, get vaccinated! If you have any questions or concerns about measles or other vaccines, or need an appointment to get immunized, please contact our office. We would love to help!