Measles: What Is It and How To Prevent It
By Gerald Rakos, MD, Chair of Pediatrics
Who could possibly have imagined back in 2000 when the CDC declared that Measles was eliminated from the United States it would once again be making front page news? Given that an excellent vaccine has existed for over 50 years, this is a disease that by now should have been relegated to discussions concerning the history of medicine and not current events. But because of persistence of the disease overseas (mostly in under-developed countries), and a growing population of unvaccinated children here, the number of cases of measles in the U.S. has been increasing steadily over the last 15 years, with a very large increase last year.
Measles is an extremely contagious virus that lives in the nose and throat. It also can live for up to several hours on a surface or floating in air. It is so contagious that it is estimated that a non-immune individual has about a 90% chance of contracting the disease if exposed. Its signs and symptoms appear about 10-14 days after exposure and include fever, rash, cough, conjunctivitis, and coryza (runny nose).
In addition to these usual symptoms some patients will develop more serious complications. These include ear infections (about 1 in 10) and pneumonia (about 1 in 20). A much more serious complication that develops in about 1 in 1000 children is encephalitis which is an inflammation of the brain. Sometimes the encephalitis occurs shortly after the more common symptoms appear and sometimes it occurs many months later. Some kids with encephalitis can develop seizures, go into a coma and even today about 1-2 out of 1000 children who get measles will die. Measles may also cause a pregnant woman to give birth early. So this is a very serious but PREVENTABLE disease.
One of the challenging aspects of controlling the disease during an outbreak is that an individual is infectious (i.e. they can spread the disease) for about 8 days including about 4 days before the rash appears. Early in the disease process, therefore, a patient is contagious but often does not know they have anything more serious than a common cold. This greatly helps the disease to spread widely as we have seen in the recent Disneyland outbreak.
The surest way to prevent getting the measles is to get vaccinated. For many years only one shot was deemed necessary. In 1989 there was an outbreak and many of the individuals who got sick had in fact been vaccinated. At that point the recommendations were changed to add a second shot. The current recommendations are for the first dose to be given at 12-15 months of age and the second between 4-6 years of age. The vaccine is about 97% effective after receiving two doses. The vaccine is given as part of the MMR (Measles-Mumps-Rubella) or MMRV (Measles-Mumps-Rubella-Varicella) vaccines. Adults who have been vaccinated do not need a booster.
There remains today some misguided concern about the measles vaccine and Autism. In 1998 a study was published in a very reputable medical journal that linked MMR vaccination with the subsequent development of autism in a small group of 12 children. The paper has subsequently been retracted by the journal because it became clear after an extensive investigation that the author manipulated evidence, had serious conflicts of interest and had broken other ethical codes. The author was found guilty of professional, ethical and scientific misconduct and lost his license to practice medicine. More importantly large epidemiological studies were done after this fraudulent paper and have found no evidence that there is a link between the MMR vaccine and the development of Autism. The purported autism and vaccine association has been called “the most damaging medical hoax of the last 100 years”1.
Importantly, there are some people who should not get the MMR and/or MMRV vaccine. This would include anyone who had a life threatening allergic reaction to components of the vaccine, or individuals with certain diseases that weaken the immune system. Talk to your doctor if you have any questions about your or your child’s eligibility for the vaccine. It is terribly important that everyone who is able to get vaccinated do so. This helps protect infants under 12 months and those individuals who are not able to be vaccinated.
The science is clear; the vaccine is safe and very effective in preventing a potentially fatal disease.
1. Flaherty DK (October 2011). "The vaccine-autism connection: a public health crisis caused by unethical medical practices and fraudulent science". Ann Pharmacother 45 (10): 1302–4.