Unvaccinated Travelers Returning From Abroad Bring Home Measles, Says CDC

American travelers who haven't kept up on their routine immunizations are bringing home more than just souvenirs when they return from trips abroad.

Measles was declared eliminated in the United States more than 10 years ago, but now, the infectious disease is back, thanks primarily to an influx of unvaccinated visitors and unvaccinated Americans who have traveled to areas in Europe, Africa and Asia where measles remains endemic or large outbreaks are occurring.

For example, the United Kingdom's Health Protection Agency said June 24 that there had been nearly 500 measles cases in England and Wales through the end of May, and there were more than 11,000 cases reported in 35 European countries during the first four months of the year.

The CDC issued a health advisory on June 22, stating that 12 foreign measles outbreaks from Jan. 1 through June 17 had led to nearly half of 156 reported cases of measles in the United States. It is the highest number of reported cases in this country since 1996.

The agency said 136 of the 156 cases involve either unvaccinated U.S. residents who traveled abroad, unvaccinated visitors to the United States, or people linked to imported cases. Eighty-five percent of the 156 cases reported occurred in people who were unvaccinated or had undocumented vaccination status.

The CDC recommended in its health advisory that physicians ensure all patients are up-to-date on measles, mumps and rubella, or MMR, vaccine and other immunizations.

The AAFP, the American Academy of Pediatrics and the CDC's Advisory Committee on Immunization Practices, or ACIP, recommend that children (1-page PDF; About PDFs) receive one dose of MMR vaccine at 12-15 months of age and a second dose at age 4 years. However, the CDC said in its advisory that children ages 6-11 months should receive one dose of MMR vaccine before traveling abroad.

Infants who receive a dose of MMR vaccine before their first birthday should receive two more doses of the vaccine, one when the child is 12-15 months old and a second at least 28 days later, the agency said.

Meanwhile, children 12 months and older should have documentation of two doses separated by at least 28 days before traveling outside the country. Teenagers and adults without evidence of measles immunity should have documentation of two appropriately spaced doses of MMR vaccine. The following are considered evidence of immunity for international travelers:

Doug Campos-Outcalt, M.D., M.P.A., the associate head of the department of family and community medicine at the University of Arizona College of Medicine, Phoenix, said that because most physicians don't see measles often -- or have never seen it at all -- some patients with measles are being misdiagnosed as having Kawasaki disease, which causes some of the same symptoms, including fever, rash and conjunctivitis.

"If a physician sees a kid and is thinking Kawasaki disease, they probably need to rule out measles," said Campos-Outcalt, who served as the AAFP's liaison to the ACIP through the committee's June 22-23 meeting and now has been appointed to a four-year term on the ACIP.

The agency said measles should be considered as a possible diagnosis in anyone with a febrile rash illness lasting three or more days, a temperature of 101 degrees or higher, and clinically compatible symptoms -- cough, coryza, and/or conjunctivitis -- who has recently traveled abroad or who has had contact with someone with a febrile rash illness. Immunocompromised patients may not exhibit rash or may exhibit an atypical rash.

The incubation period for measles from exposure to fever ranges from seven to 12 days. The period from exposure to rash onset is typically 14 days but can range from one week to three weeks.

The CDC recommended that physicians who suspect measles in a patient obtain specimens for testing, including viral specimens for confirmation and genotyping.

According to the agency, patients with suspected cases of measles should be isolated immediately, and the cases should be reported promptly to local health departments. The virus remains contagious for as long as two hours on surfaces and in the air after an infected person leaves a room.

"This is a very infectious disease, so if someone comes in -- particularly if they've traveled in or they come from these countries (where measles remains problematic) -- and they have these symptoms, you isolate them," Campos-Outcalt said. "You should not let them sit in a room full of other patients."