To Stop Local Measles Outbreaks, International Travelers Need to Get Vaccinated — But Only 47% Do
In the worst measles outbreak in the state since 1990, the Minneapolis Department of Heath races to contain the spread of an infection believed to have originated from an infected traveler. Mistaken attitudes and unvaccinated travelers are creating a world of hurt and disease for Americans. A recent study found that more than half of eligible travelers from the US are electing to skip their pre-trip measles vaccine.
Measles, also called rubeola, is a highly contagious disease caused by a paramyxovirus. The virus, first described in the 7th century, causes a severe respiratory infection, rash, cough, and runny nose. In about 30% of cases, complications like fever, diarrhea, pneumonia, and encephalitis can occur.
Direct contact is not needed to spread the measles infection. About 18 people, on average, are infected by one measles patient. Measles is so virulent that 90% of unvaccinated people who walk into a room occupied by an infected measles patient will become ill — even two hours after the infected patient left the room.
Around the world, measles is spreading widely in 2017, with Romania and Italy suffering large outbreaks due mainly to unvaccinated populations.
Although measles was eliminated in 2000 as a disease that naturally occurs in this country, outbreaks continue to occur due to unvaccinated travelers returning from abroad, or visiting the country. In 2014, the US had 667 cases of measles, the highest annual case count since 2000.
Factors that cause travelers to return to the US bringing dangerous, contagious, diseases are a real concern. In the study, published in the journal Annals of Internal Medicine, researchers took a look at why US travelers are leaving the country without vaccinations that can protect the and keep communities safe from infection on their return.
Scientists at Massachusetts General Hospital looked a data from travelers between the years 2009 and 2014 that was gathered from GlobalTravEpiNet clinics throughout the US. The clinics are intended to provide information and services to travelers heading to high-risk areas.
These clinics are primary care facilities, public health agencies, and practices associated with medical schools and hospitals. The travelers, all over age 18, were assessed for prior exposure to the measles or vaccination. From an original group of 40,810 participants, 6,612 were determined to be eligible for the measles mumps and rubella (MMR) vaccination.
This was fairly straightforward research that sought a better understanding of why people are leaving the US without vaccinations that are considered necessary. Overall findings of the research include:
- The most common destination was Africa, followed by Central and South America.
- Median age of travelers within that time frame was 33 years of age.
- Of those eligible for the MMR, 3,135 (47%) were vaccinated at the clinics.
This left 3,477 (53%) MMR-eligible travelers who were not vaccinated at the time of their visit to the clinic. Figures on these unvaccinated travelers include:
- Most of the non-vaccinated travelers visited clinics in the southern US.
- Of these travelers, 1,689 (48%) simply refused the MMR. The most often-cited reason was that they "were not concerned about the illness." In an editorial, the authors note that measles is a serious, contagious disease which deserves the same respect from travelers as yellow fever or malaria.
- A surprising 966 travelers (28%) were not vaccinated due to lack of recommendation by the healthcare provider. Of these, doctors reported they felt the vaccine was "not indicated," or that there was insufficient time before travel.
- There was also a group of 822 (24%) that were not vaccinated due to health system barriers, which generally meant a referral to another provider for vaccination.
This report importantly highlights the basic reasons why travelers are returning to the country infected with preventable diseases. Lack of information leads to poor choices by travelers, and physicians are not taking an opportunity when presented to help protect travelers and the community at large.
The study notes that most people who visit the clinics are already interested in their health — having taken the time to find the clinic and make an appointment. The authors also noted actual vaccination numbers are likely to be lower, since the majority of travelers may not visit their family physician for advice and vaccinations before heading overseas.
"All unvaccinated travelers who are medically able to receive MMR vaccine should do so," the study authors write. "The risks are minimal for the individual who receives the vaccine and are greatly outweighed by the benefit to the traveler, as well as to society, on his or her return."