Despite clinical recommendations, more than half of eligible U.S. travelers are not getting vaccinated for measles, mumps and rubella before leaving the country, and increased vaccination of international travelers is needed to reduce the importation and transmission of measles virus, according to recent data.
“When evaluating patients before international travel, some health care providers may not be aware that measles is a travel-associated illness, despite [Advisory Committee on Immunization Practices] recommendations,” Emily P. Hyle, MD, MSc, from Massachusetts General Hospital, and colleagues wrote in Annals of Internal Medicine. “A single imported measles case can lead to many secondary and tertiary cases, so imported measles cases often have a wide-reaching effect in the United States...The risks for measles transmission are magnified in communities with a higher prevalence of unvaccinated adults and children.”
Hyle and colleagues analyzed how providers assessed the measles immunity status of departing U.S. adult travelers seeking pretravel consultation, and the reasons given for nonvaccination among those eligible to receive MMR vaccine. They conducted an observational study of adults aged 60 years or younger attending pretravel consultation at 24 U.S. clinical sites associated with Global TravEpiNet (GTEN), a CDC-funded consortium. Using a structured questionnaire, they assessed the information completed by travelers, including age, medical conditions, destination, reason for travel and duration of trip. Providers took information regarding immunization history, health advice provided, vaccines administered and medications prescribed during pretravel consultation.
Out of 40,810 adult travelers included in the study, providers considered 6,612 (16%) to be eligible for MMR vaccine at the time of pretravel consultation. Of these adults eligible for MMR vaccine, 53% were not vaccinated during the visit due to traveler refusal (48%), provider decision (28%) and health system barriers (24%). The researchers found that most unvaccinated MMR-eligible travelers were evaluated in the South (65%) or at nonacademic centers (51%). They also observed that nonvaccination because of traveler refusal was more frequent in the South (63%) and in nonacademic centers (66%). In the Northeast, the most common reason for failure to vaccinate an MMR-eligible traveler was provider decision (52%).
“Increasing measles immunity in travelers should substantially reduce the risk for measles importation and, by extension, decrease the number of new measles cases seen due to transmission within the United States,” Hyle and colleagues wrote. “In light of recent measles outbreaks associated with travel, pretravel measles immunity screening for U.S. adults traveling internationally and MMR vaccination for those eligible should be prioritized.”
In a related commentary, Lori K. Handy, MD, MSCE, from Thomas Jefferson University, and Paul A. Offit, MD, from the University of Pennsylvania and Editorial Board member for Healio’s Infectious Disease News, urged those eligible to receive MMR vaccine to get vaccinated. “If persons traveling abroad continue to underestimate the importance of pretravel MMR vaccination, our society is destined to be affected by imported cases of measles, leading to morbidity and mortality from this disease,” they wrote. – by Savannah Demko
Disclosure: Hyle reports receiving grants from NIH and CDC during the conduct of this study. Please see the full study for a complete list of all other authors’ relevant financial disclosures. Handy and Offit report no relevant financial disclosures.