Sixteen cases of imported measles occurred in the United States in the first two months of 2011, many among unvaccinated children, according to the CDC.
“An estimated 1.9 million U.S. children travel overseas each year and often are at risk for acquiring infectious diseases that might not be common in the United States,” Preeta Kutty, MD, of the CDC, and colleagues wrote in Morbidity and Mortality Weekly Report.
They analyzed data from the National Notifiable Disease Surveillance System from January 2001 to February 2011. In the first two months of 2011 the researchers identified a total of 29 measles cases — 28 of which were import-associated and 13 of which occurred among U.S. residents.
Of these 13 measles cases, seven occurred in children aged 6 to 24 months, none of who had been vaccinated with measles, mumps and rubella vaccine prior to traveling.
During the entire 10-year period, the researchers identified 692 cases of measles, 82% of which were import-associated. U.S. residents accounted for 159 of the cases, 47 of which occurred among children. Among the 47 affected children, just three had been vaccinated.
Current recommendations from the CDC’s Advisory Committee on Immunization Practices and the American Academy of Pediatrics state that all children traveling internationally be vaccinated – those younger than 12 months should receive one dose of MMR, whereas children 12 months and older should receive two doses, separated by at least 28 days.
However, many parents choose to opt out of having their child vaccinated with the MMR vaccine due to a lack of a perceived risk of disease and unfounded fears concerning an unproven link between the vaccine and autism.
“The frequency of imported measles among children aged 6 to 23 months also suggests that parents and clinicians might not be aware of recommendations to administer MMR vaccine to children as young as 6 months when they are traveling abroad,” the researchers wrote.
They also emphasized that “clinicians should maintain a high level of suspicion for measles in patients with febrile rash illnesses and recent travel outside the United States,” to prevent delays in diagnosis and treatment.
Clinicians that suspect a patient has measles should notify the local health department and obtain specimens for testing, disease confirmation and genotyping, the CDC advises.