R.D. Zimmerman had been to northern Africa and the Caribbean, spent lots of time in Russia and visited Mexico multiple times. But a couple of weeks after returning home to Minneapolis from a visit to Cabo, on the southern tip of Baja California, he developed a persistent cough that landed him in the emergency room with an unexpected diagnosis: hepatitis A.
Caused by a virus, the contagious liver disease is easily preventable with a vaccine — which Zimmerman, 63, didn't realize he had neglected to get. His last round of shots had been in 1994, a year before the hep A vaccine became available, and he hadn't thought to check since then if he was up to date.
Neither did his doctors or his husband, who soon came down with hep A, too. At its most severe, the disease can cause jaundice, fever, diarrhea and even death. Recovery can take months, as it did for Zimmerman, an author and a friend of mine.
"We had travel insurance to be med-evaced out of there and all this stuff, but we didn't think about vaccines," he said. "I felt like a knucklehead."
It's impossible to know how many people contract vaccine-preventable diseases while traveling internationally each year, in part because diseases such as hep A have weekslong incubation periods and can be acquired at home.
Anecdotal evidence suggests that Zimmerman's experience is common, said Greg Poland, director of the Mayo Clinic's Vaccine Research Group in Rochester, Minn. He sees patients every week who come home from trips with illnesses they could have avoided, including hep A, which often comes from consuming contaminated food or water.
"Hepatitis A is the poster child for what happens in Mexico," Poland said, adding that it's one of numerous diseases frequently picked up abroad.
"Most people will tell you they weren't aware they were going to some place that had a larger risk," added Andrew Pekosz, a virologist at Johns Hopkins University Bloomberg School of Public Health. "Or that they hadn't gotten the vaccine or taken the appropriate antimicrobial drug that would have minimized the risk."
Retirement is a popular time to hit the road and see the world, but travelers face new health concerns once they hit their 60s. Because immunity tends to drop over time, symptoms are often more severe and complications become more common as people age, especially if they have heart disease, diabetes or other conditions.
Vaccines also become less effective after about age 65, but because recovery is tougher, immunizations become especially important. "For most of these vaccines, the side effects and adverse effects are minimal compared to the diseases," Pekosz says. "You're better off getting the vaccine."
It's worth visiting a travel clinic at least two or three months before a trip to find out which vaccines are recommended for where you're traveling and whether there are any contraindications with medications you might be taking, experts advise. Planning is important because some vaccines, including hep A, involve more than one dose, spaced months apart, and it may take weeks before a shot starts offering protection. Other immunizations require boosters every few years. That makes it easy to be delinquent, even if you think you're protected.
About a dozen vaccines might show up on your to-do list. The most common are hep A; diphtheria-tetanus-pertussis (DTaP), which protects against bacteria that can enter through open wounds and requires a booster every 10 years; measles-mumps-rubella (MMR); chickenpox (varicella); polio; and an annual flu shot.
Vaccines that may be warranted depending on your destination include those for hepatitis B, Japanese encephalitis, rabies, yellow fever, meningococcal disease and typhoid, which is available as a shot or as a series of capsules, each with its own booster interval. Starting up to a couple of weeks before you leave, you may also want to take a malaria prophylaxis, which isn't available as a vaccine but can help prevent the disease while you're taking the medicine.
Vaccines aren't the only strategy for staying healthy abroad. Among other precautionary measures, experts suggest bringing sunscreen, bug spray, long sleeves and a complete first-aid kit packed with a broad-spectrum antibiotic and medications for motion sickness and anything else that could ruin a trip. Any essential drugs for chronic conditions should go in your carryon bag, Poland said, in case your checked luggage disappears.
Other tips include practicing good hygiene, being vigilant about what you eat and drink, and investigating hospital locations and insurance coverage near your destination before taking off. Specialized travel insurance plans can cover treatments and evacuations that Medicare and private plans might not. If you do get sick overseas, Poland said, don't delay seeking help. A downward health spiral in a developing country can end badly.
Like reserving hotel rooms and making itineraries, thinking about health should be part of your travel-planning routine, experts say. The travel website of the Centers for Disease Control and Prevention is often a good place to start investigating destination-specific information and advisories.
"Once you book flights and travel, it is a really good opportunity to then say, 'Maybe I should go to a couple of websites and see if there is anything I can prepare from a health standpoint,' " Pekosz said.
After I learned about Zimmerman's diagnosis last spring, I made a call to check on my own records. I'd been to the Peruvian Amazon in 2001 and remembered getting a slew of vaccines at a travel clinic beforehand, including rabies shots to protect me from vampire bats. As I embarked on many foreign trips since then, I assumed I was buffered against everything I might ever encounter. As it turns out, I had started the hep A series too close to my departure date and had never followed up with the second shot. I went to the clinic that day and got caught up.