Resurgence of measles in the United States
For the generations who grew up before the 1960s, contracting measles was an accepted fact of life. Spread by an infected person's sneezes and coughs, the highly contagious viral disease wasn't just an annoyance that caused high fevers and an itchy rash: It killed people. In the decade prior to the start of the measles vaccination program, it is estimated 3 to 4 million people in the United States were infected each year, with 48,000 hospitalizations and nearly 500 deaths.
But due to a successful measles vaccination program beginning in 1963, measles was all but eradicated in the U.S., and many parents and doctors have never even witnessed a case. Because of this lack of familiarity and a vocal anti-vaccine movement among parents who feel—despite a paucity of scientific evidence—that there are connections between vaccines and autism, some parents have chosen not to vaccinate their children, leading to an increase in measles cases. According to recent data from the Centers for Disease Control and Prevention, measles cases are at their highest level in more than a decade. In the first seven months of 2008, 131 cases were reported in the United States.
We spoke with Ronald Samuels, MD, MPH, about the rise in measles cases.
What is measles?
Measles is a severe viral infection that causes very high fevers and a rash. If you are in the United States or another developed country, the fatality rate is one in 1,000. There is no real treatment for measles; the only adequate treatment is prevention. Once kids get measles, our treatment is just supportive care, fluids and fever control. Worldwide, there are still more than a quarter-million deaths a year from measles.
What are the dangers of acquiring measles?
Most people who die from measles actually die from complications of the measles, as they become susceptible to pneumonia and other infections while they are sick. They also can get encephalitis (brain swelling) from the disease.
At what age should children get the measles, mumps, rubella (MMR) vaccine?
All children should receive a vaccine between 12 and 15 months of age for the first dose, and a second dose at age 4 or before. Any child 6 to 12 months of age, who normally would be too young to be vaccinated in the United States, should be vaccinated if traveling to any destination where measles has not been eradicated, which includes most of Europe, the Caribbean, and south and central Asia. Those children should then be revaccinated according the United States schedule after 12 months of age, as the MMR doesn't provide long-term protection if a patient received it before 12 months of age.
What are the side effects of the MMR?
The shots hurt when you get them. They can also cause fever and mild rash one to three weeks later. It's very different from most vaccines—most kids who do get a mild fever don't get it until a few weeks after the shot.
Who should not receive the vaccine?
People with severe egg allergy should be vaccinated only with care. People who are significantly immunocompromised should discuss with their doctor before receiving the vaccine.
What is driving this increase in measles?
We are seeing these new "pockets" or clusters of decreased vaccination, which are fueling outbreaks. Measles is very contagious; it takes just a few people to contract it, and then it spreads like wildfire. Most of the cases of measles we see in the United States are imported from overseas. For example, somebody from India comes to visit the United States, or someone from the US goes to Switzerland, catches it there and brings it back. We're having unvaccinated people do foreign travel and then come home and expose other unvaccinated people.
Second, we're also seeing a lot of unvaccinated young children traveling overseas to places where they are exposed and then bringing it back. Measles is much more common in the rest of the world than people realize.
What is the effect of people individually opting out of the vaccine in their communities?
When people opt out, they substantially raise the chance that measles will be transmitted around the community, not only to their child, but to children who can't be vaccinated, or to the small number of children for whom the vaccine just doesn't work. The kids at most risk are those under 1 year of age who are not yet routinely vaccinated yet.
What do you think is concerning parents who don't vaccinate their children?
First, most people underestimate the risk of diseases they haven't seen in a long time and overestimate the risk of vaccines. Second, there are some specific concerns people have, especially around autism, which almost always develops in the second year of life concurrent with the time we give multiple vaccines. It's almost always going to be true that a child who develops any illness in the second year of life is going to contract it soon after one of these vaccines. There is a lot of evidence that the vaccine is not related to autism, but people throughout history have always been afraid of vaccines.
How do you reassure parents who are worried about giving their child the vaccine?
I tell parents that they are always right to worry about their child. If you're not worried about your child, you're not being a good parent. But people underestimate the risks of the disease. They say it's 10 days of fever; well it's 10 days of fever unless your child dies. If I told you it's a one in a 1,000 chance that your child's going to die, what would you do? What you're betting is not that the disease is mild, but that your child is not going to get the disease. If your child gets the disease, it's a real risk, and if people don't vaccinate their kids, the risk goes way up.
Data from the World Health Organization (WHO) fact sheet on measles, Nov. 2007
Measles remains a leading cause of death among young children worldwide, despite the availability of a safe and effective vaccine for the past 40 years.
In 2006, it was estimated that there were 242,000 measles deaths globally: This translates to about 663 deaths every day, or 27 deaths every hour.
The overwhelming majority (more than 95 percent) of measles deaths occur in countries with per capita Gross National Incomes of less than US $1,000 and weak health infrastructures.
- Vaccination has had a major impact on measles deaths. Overall, global measles mortality decreased by 68 percent between 2000 and 2006. The largest gains occurred in Africa, where measles cases and deaths fell by 91 percent.