Measles Vaccine Refusal Helps Make 2014 a Record Year
The number of measles cases in 2014 through May 23, the highest year-to-date total since 1994, has the Centers for Disease Control and Prevention (CDC) worried that the virus may become endemic again on US soil as it spreads from overseas travelers to pockets of vaccine refusers.
The CDC has received reports of 288 confirmed cases of measles — none fatal — from January 1 through May 23, with 280 associated with importation from at least 18 countries, according to an article published online May 29 in the Morbidity and Mortality Weekly Report. Most of the 45 individuals who actually imported the virus were US travelers returning from abroad.
In 69% of the 288 cases, the person was unvaccinated. In another 20%, vaccination status was unknown. For 195 US residents who had measles and were unvaccinated, 165, or 85%, declined a shot for religious, philosophical, or personal reasons.
The United States had 764 measles cases in 1994 through May 23, and 963 by year's end, according to data released at a press conference today.
The CDC declared in 2000 that the United States had eliminated measles as an indigenous disease, meaning there was no longer any year-round endemic transmission of the virus. Although this country's status has not changed, other countries such as the Philippines are rife with the disease.
Anne Schuchat, MD, director of the CDC's National Center for Immunization and Respiratory Diseases, warned at the press conference that the findings are a "wake-up call."
"Measles anywhere in the world can reach our country, and unvaccinated Americans are at risk," said Dr. Schuchat. "Measles can really get out of control quite quickly. You can get indigenous spread if you can't break the chain of transmission."
As of now, 15 scattered US outbreaks that account for 79% of all cases are "being contained," said Dr. Schuchat. The largest outbreak, involving 138 cases, has hit unvaccinated Amish communities in Ohio that had dispatched aid workers to the Philippines, which is recovering from last year's Typhoon Haiyan.
Vaccinate Before Takeoff
One key to lowering the measles case count, said Dr. Schuchat, is for Americans with international travel plans to get 2 doses of the measles, mumps, and rubella (MMR) vaccine if they haven't been vaccinated or don't know their immunization status. The 2-dose regimen also applies to healthcare workers and childcare attendants who are catching up on measles protection. As always, pregnant women and individuals with suppressed immune systems should not receive the vaccine.
Dr. Schuchat noted that individuals born before 1957 probably had measles at some point, which relieves them from getting the shot. The vaccine debuted in 1963. She described it as "very safe and effective."
Routine vaccination for children consists of a first dose at 12 to 15 months of age and a second dose at 4 to 6 years of age. If someone is traveling internationally with a child aged under 12 months, however, the CDC recommends a single dose before departure. Such a child should receive a second dose at 12 to 15 months and a third at least 28 days later. Children aged 12 months or older should have 2 doses separated by at least 28 days.
More information on the CDC's recommendations for measles vaccination is available on the agency's Web site.
Morb Mortal Wkly Rep. Published online May 29, 2014. Full text