Background: Measles outbreaks persist in the United States (US) because of imported cases, most of which are due to returning US travelers infected abroad. We sought to determine the measles immunity status of departing US travelers seeking pre-travel advice and reasons for non-vaccination among the vaccine-eligible.
Methods: We used data collected during pre-travel consultations (2009-2014) from 24 sites associated with Global TravEpiNet (GTEN), a Centers for Disease Control and Prevention (CDC)-sponsored consortium. We used provider-collected data regarding itineraries, travelers' medical conditions, and vaccination histories. We defined measles immunity as a positive serology, history of 2 measles-mumps-rubella (MMR) vaccinations, or self-reported prior measles illness. Providers could indicate immunity without a specific reason (“Immune not otherwise specified”). We defined travelers who did not meet criteria for immunity or medical exemption as “vaccine-eligible,” for whom CDC guidelines recommend pre-travel MMR vaccination. If MMR was not administered, providers selected a rationale from a list of possibilities. Analyses were conducted using SAS, version 9.2 (SAS Institute Inc., Cary, NC).
Results: Of 40,817 adult travelers born ≥1957, 7,181 (18%) were vaccine-eligible, of whom 44% were vaccinated (Figure 1). Non-vaccination was due to provider or patient decision (52% vs 48%, respectively). Providers most frequently deemed the vaccination “not indicated” or referred the patient to a primary care provider (PCP); patients frequently refused vaccination because they were “not concerned about illness.”
Conclusion: Eighteen percent of US adult travelers who presented at GTEN sites merited MMR vaccination, but fewer than half of them were vaccinated at the pre-travel consultation. Our estimates could under-represent the opportunities for vaccination, as providers often did not require formal documentation of measles vaccination and accepted verbal history of disease and non-specified determinations of immunity. To reduce measles importations, patients and providers need further education regarding measles risk that emphasizes the importance of vaccinating non-immune travelers prior to departure.
E. Jentes, None
A. P. Fiebelkorn, None
S. Hagmann, None
R. Walensky, None
E. Ryan, None
R. Larocque, None