Infectious disease expert talks measles outbreak
Measles has made widespread news again, following an outbreak linked to California's Disneyland in December. The Centers for Disease Control and Prevention (CDC) has reported more than 100 cases in January, and the organization even issued a health advisory following the outbreak. The respiratory disease is highly contagious, but also preventable with the MMR vaccine. Le Bonheur Chief of Infectious Disease Sandra Arnold, MD, shares some important information regarding the disease and vaccination below.
A history of measles in the U.S.
Measles used to be a common childhood disease, until the vaccine came along and children were universally vaccinated against it. A measles vaccine was introduced in 1963. In 2000, measles was declared eliminated in the United States.
Since then the number of measles cases reported has decreased by more than 99 percent to 60 cases per year on average. About a third of these are imported from overseas where measles has not yet been eliminated.
About the disease
Measles is an infection caused by a virus that leads to fever, cough, stuffy runny nose and a rash. Measles is so contagious that, when it was common, almost everyone had it by the time they were 20 years old. Most cases are benign.
Common complications include ear infections, pneumonia, croup, and diarrhea. The most common serious complications, encephalitis, or infection and inflammation of the brain, and death occurred in 1-3 of 1000 children. Rarely, a degenerative central nervous system disease characterized by behavior and intellectual deterioration and seizures called subacute sclerosing panenchephalitis (SSPE) can occur in 7-10 years after having measles infection. These complications were most likely to occur in children under 5 and children with depressed immune systems, such as those taking chemotherapy for cancer.
Measles vaccine today
The measles vaccine is now administered along with the vaccine against mumps and rubella (MMR) in a combined injection after a child’s first birthday. Five percent of those vaccinated do not have immunity after the first vaccination, which is why the second MMR is required at 4-6 years of age.
Infants who travel abroad where measles is endemic should be immunized prior to going overseas, but will still require the vaccinations at 1 year and 4-6 years of age.
Why is measles back?
There is no question that the vaccine has been enormously successful in decreasing the incidence of measles and its complications. Complications, such as SSPE, are virtually unheard of in the United States since widespread use of the vaccine.
However, this is being threatened by increasing refusal of the vaccine for philosophical or religious reason. There is no link between MMR or any other vaccine or vaccine additive to autism.
In 2014, there were 23 outbreaks of measles in the U.S. with 644 cases from 27 states. This includes a large outbreak of 383 cases in primarily unvaccinated populations in Ohio. There were also many cases associated cases from a large outbreak in the Philippines. This case number represents and substantial increase from 2013 when there were just fewer than 200 cases.
The CDC, as mentioned above, has already reported more than 100 cases this year from Jan. 1-30 associated with exposure to a case of measles at the Disneyland Resort Theme Parks in California. So far there have been 102 cases (in just one month) reported in 14 states (not yet including Tennessee). Most of these cases have occurred in children who have not been vaccinated: those who cannot be vaccinated due to young age or an illness that precludes vaccination and those who have chosen for their children not to be vaccinated.
The importance of the measles vaccine is clear.
Those who are infected are contagious four days before the appearance of the rash. Since the early symptoms are so similar to that of the common cold, infected persons often don’t know that they’re infected and can pass it on to others who do not have immunity. This is not limited to those who refuse immunizations, but extends to those who can’t have the vaccine due to age or for medical reasons. Even when the infection is mild, measles results in missed school and work. Please, vaccinate your children against measles to continue protecting them and the community.
For more information about measles:
- Centers for Disease Control and Prevention
- CDC fact sheet
- World Health Organization fact sheet
- CDC Vaccine information