So far this year, over 1,100 cases of measles have been reported across the United States. This highly contagious virus poses a threat, not just in emergency rooms or doctors’ offices, but also in unexpected places like concert venues, shopping malls, and airports in several states.
The US Centers for Disease Control and Prevention (CDC) noted that “Travelers can catch measles in many travel settings including travel hubs like airports and train stations, on public transportation like airplanes and trains, at tourist attractions, and at large, crowded events.” Infected individuals can bring the virus home, where it can spread quickly among those who aren’t immune.
This situation might feel unusual for Americans. Back in 2000, measles was declared eliminated in the US due to effective vaccination strategies. Only a handful of cases were reported that year, all of which were from abroad. However, more than 1,157 cases have been documented recently, making this the second-highest year for cases since 2000, just after 2019, which recorded 1,274 cases.
The bulk of this year’s infections stem from an ongoing outbreak in West Texas, which seems to be stabilizing, yet concerns are rising about potential spreads due to summer travel, according to Lori Tremmel Freeman from the National Association of County and City Health Officials.
In Gaines County, the heart of the outbreak, many in the community have either gained immunity through infection or have been vaccinated. Still, Freeman cautioned about the risks associated with travel during the summer months.
With heavy travel expected, she warned, “The spread could continue throughout the rest of the country as these groups become mobile and still carry the disease.”
The CDC has stressed that international travelers should ensure they are fully vaccinated with the two doses of the measles-mumps-rubella (MMR) vaccine. Infants between 6 to 11 months traveling should also receive an extra dose.
Dr. Peter Hotez from the Texas Children’s Hospital Center for Vaccine Development confirmed this recommendation for infants was echoed by the Texas health department in the ten counties experiencing increased measles transmission this year.
He mentioned this means that some infants may require three doses instead of the usual two, which are given at 12 to 15 months and again at 4 to 6 years. However, he reassured that “The MMR vaccine is one of the safest vaccines we know.”
Interestingly, adults born before 1957 aren’t recommended to receive the MMR vaccine based on the assumption that they’ve likely been exposed to measles in their early years. Nonetheless, health care workers in outbreak areas are advised to get vaccinated regardless of their birth year.
Hotez pointed out that vaccine recommendations can change as outbreaks evolve, emphasizing the need for people to stay informed through local health officials’ updates.
The MMR vaccine is not advisable for pregnant women, infants younger than 6 months, or individuals with significantly weakened immune systems.
As for those who can’t get vaccinated, Dr. Scott Roberts at Yale School of Medicine suggested that discussions with a doctor about personal risk levels are crucial, especially concerning the availability of therapeutics in their travel destination.
Immunoglobulins, which are antibodies produced by the body, can be provided in a hospital setting for those exposed to measles, particularly individuals with compromised immune systems.
Historically, measles outbreaks in the US have generally stemmed from individuals without immunity traveling abroad, contracting the virus, and then returning home. While some cases have indeed been imported by international travelers, those cases represent a minority.
Roberts noted that while no country enforces MMR vaccination proof for travel, it’s wise for travelers to confirm their immunity status prior to international trips.
Immunity can include prior infections, proof of birth before 1957, lab tests showing immunity, or documentation of MMR vaccinations.
Travelers should check their status at least six weeks before departure. Full immunity necessitates two doses of the MMR vaccine spaced at least 28 days apart and the two weeks required for immunity to develop after the last dose.
The two doses of the MMR vaccine are 97% effective against measles, which means vaccinated travelers who may have been exposed should feel relatively secure, even though there’s still a small chance—3%—of getting infected. Symptoms, however, are typically much milder with vaccination.
If someone hasn’t been vaccinated and suspects exposure, it’s advisable to see a doctor promptly. Depending on timing post-exposure, they might still receive immunoglobulin or the MMR vaccine to alleviate symptoms.
Beyond verifying immunity, Roberts recommended standard travel precautions like carrying essential medications, knowing nearby hospitals, and following travel health notices from the CDC relevant to their destination.
Additionally, he urged travelers to maintain hygiene through frequent handwashing, avoiding sick individuals, ensuring good ventilation, and wearing masks if they are at risk of severe illness. These practices can help prevent measles and also reduce the spread of other illnesses like Covid-19 and the flu.
Measles is extremely contagious; it’s been noted that on one occasion, four travelers contracted the virus from a single person at an airport gate. “This highlights how contagious [measles] is,” Roberts commented. “Even airports and terminals are risky.”
Given the current measles outbreak, Hotez stressed its seriousness. In the 1980s, measles was a leading cause of death among children, accounting for millions of fatalities. Although global immunization efforts have decreased the deaths to around 100,000, it remains significant. In Texas alone, there have been more than 90 hospitalizations and two deaths attributed to measles this year.
