U.S. Measles Cases Reported in 2011 Highest in 15 Years, Says CDC

The number of measles outbreaks reported last year in the United States -- 17 -- was more than four times the usual number, with 222 people from 31 states contracting the infectious disease. That's according to Anne Schuchat, M.D., director of the CDC's National Center for Immunization and Respiratory Diseases, who said that 2011 posted the largest number of U.S. measles cases reported since 1996, when 508 cases were reported.

During an April 19 press briefing, Schuchat said two factors played key roles in the higher caseload: disease importation by U.S. citizens returning from travel abroad or by foreign nationals visiting the United States and those individuals' interaction with unimmunized people. In all, 200 cases were linked to such importations, she noted.

"There were 72 actual importations from other countries, and nearly half of them were from the European region," said Schuchat. "Most of us don't think of Europe as a place where you can catch an infectious disease, but, recently, there has been a lot of measles in Europe."

Schuchat said that in 2011, more than 37,000 measles cases were reported across Europe, with some of the hardest-hit areas being places where Americans frequently travel, such as France, Italy and Spain.

"It's very important for travelers heading off to Europe to make sure they are up-to-date on their immunizations and to make sure their children are, as well," she said.

A compounding factor was that 86 percent of those infected were not vaccinated against measles or did not know if they were vaccinated. Of the 166 U.S. residents who were unvaccinated or had unknown vaccination status, 141 people were eligible to receive the measles, mumps and rubella (MMR) vaccine. Sixty-six of those individuals were between the ages of 16 months and 19 years, said Schuchat, "when they should have already gotten the vaccine, and when school requirements or daycare requirements would have been good reminders they were eligible and expected to be vaccinated."

Of those 66 people, 50 -- or 76 percent -- reported a philosophical objection or a religious or personal belief exemption to vaccination. The other cases occurred in children who were too young to be vaccinated or in adults who may not have had accurate immunization histories.

"Unvaccinated people put themselves and other people at risk for measles and its complications," said Schuchat. "They particularly put at risk people who are too young to be vaccinated, who can sometimes have the worst complications from measles. The continuing story of measles is that we're still having importations and disease this year, with more than 25 cases reported so far in 2012, most of them associated with importation."

Schuchat said the CDC continues to strongly recommend that people of all ages keep up-to-date with all of their vaccinations and specifically recommends that children receive two doses of MMR vaccine: the first dose at age 12-15 months and the second dose at age 4-6 years.

"We really think it's important for parents to know the MMR vaccine is safe and very effective," she said. "Measles can be serious, your child can get it, and your child can spread it to people who can't even get the vaccine because they're too young or they have problems like leukemia."