Who, what, when, where, and why are the questions to ask when a patient comes in for travel vaccinations.
Recommendations vary and must be individualized according to the traveler’s plans, said Dr. Loren Miller, director of the infection control program at Harbor-UCLA Medical Center in Torrance, Calif.
Some infections may be common worldwide, but treatment resistant in certain regions. Some vaccinations must be started weeks before travel. Some infections occur only during the dry season or in rural areas. And some are particular to patients who anticipate a vacation of sexual freedom.
"This might be awkward to ask, but you need to take a sexual history," said Dr. Miller, "Some travelers go with the express intent of having sexual activity, or at least the possibility that it might occur during their travel. For them, a hepatitis B vaccine is certainly recommended."
The first priority in any travel health consultation should focus on the easiest and most effective way to avoid the most common illness: travelers’ diarrhea. "Don’t drink tap water and don’t eat fruits and vegetables that have been rinsed under tap water is the best advice you can give," he said.
However, Dr. Miller said, prophylactic antibiotics are quite effective, reportedly cutting the rate of diarrhea from 40% to 4%. "That figure might not accurately represent what is going on in 2011, however," he cautioned. "These days, fluoroquinolones are the only agents effective in most countries, where antibiotic-resistant bacteria are common. And some of these drugs have lots of drug interactions and potential toxicities."
The Centers for Disease Control and Prevention does not recommend prophylactic treatment unless the trip is considered critical and even a short bout of diarrhea would impact its purpose. "In other words, if you’re on a peacekeeping mission for the U.S. president, take it. Others should not."
An alternative for some reliable patients is to dispense a course of treatment to take in case they come down with the illness. In that case, destination, trip duration, and planned activities are key considerations.
"I have two words for you," to prioritize travel vaccinations, Dr. Miller said: "Yellow Book. And not the one with the phone numbers."
The Yellow Book is the CDC’s interactive, online guide to travelers’ vaccines, including malaria prophylaxis. To use the book, simply click the destination on a drop-down menu. "This will take you to a map of the country and list the vaccinations you should get as well as when you should get them and whether they are required for entry into the country."
The book also includes other important information, such as details on radiation releases in Japan, or the measles outbreak seen in many countries this year.
"Prioritizing is key when planning," Dr. Miller said. "These vaccines are not cheap; to get the entire series can be really expensive and some travelers can’t, or won’t pay. Other things to consider are the patient’s own risk tolerance and the likelihood of infection. Get an idea of some of the activities; will they be mostly urban or rural? Is there adventure travel?"
Since most travel clinics are run by general practice physicians, and not infectious disease specialists, it’s important for providers to do some reading and research before dispensing advice. "For example," he said, "you should know that you can’t give any live oral vaccine along with an antibiotic, or the vaccine will be killed in the stomach."
Some of the more commonly recommended vaccines are for coverage against:
• Yellow fever. "This is single live attenuated vaccine that’s really safe. Some countries even require proof of vaccination to enter," he said. It should not be administered to people older than 70 years, and it can’t simply be ordered up from the pharmacy. "You have to apply to the state health department in order to give this vaccine," Dr. Miller noted. Endemic areas include South America and African countries.
• Japanese encephalitis. "This vaccine was introduced in 2009 and has an excellent safety and efficacy profile," he said. The disease is endemic to rural farming areas in Southeast Asia and the Indian subcontinent, but also in some temperate regions of China and Japan; it peaks in summer and fall.
• Meningococcal vaccines. One vaccine is licensed for adults of all ages, and one only for adults younger than 55 years. "The vaccine protects against most serotypes, but not all," Dr. Miller said. "We really recommend it for travel to the ‘meningitis belt’ in Africa, especially during the dry season, which is when many people make the Hajj pilgrimage."