June 10, 2009

Taking the Bite Out of Travel

After leaving his job as a research analyst recently, 34-year-old Kristian Jhamb is preparing to visit several African countries, go on safari, climb Mount Kilimanjaro, and then head to the islands of Micronesia.

His first stop: the travel medicine clinic at NewYork-Presbyterian Hospital/Weill Cornell Medical Center, where Mr. Jhamb received six vaccines, including for yellow fever, typhoid and hepatitis A, as well as antimalaria pills and antibiotics to take along on his trip. The total cost was more than $500, but "it was worth it for the peace of mind," says Mr. Jhamb. "I probably was traveling pretty recklessly in the past because I wasn't immunized for any of these things."

While swine flu has dominated the news as a concern for travelers, experts say other infectious diseases pose a far greater threat as the summer travel season gets under way. Especially worrisome are mosquito-borne diseases, including malaria, dengue fever, Japanese encephalitis, chikungunya fever and yellow fever, which are now spreading in areas where they weren't previously a danger. Travelers are also at increased risk for intestinal and skin-burrowing parasites, tick-borne diseases, sexually transmitted diseases, typhoid fever and the age-old scourge, traveler's diarrhea.

The coming 2010 edition of the Centers for Disease Control and Prevention's Yellow Book -- the widely used reference guide to travel medicine -- includes extensive warnings on 20 diseases that received only cursory mention in the 2008 edition. The new book also features first-time health-risk profiles for popular tourist destinations, such as Peru's Machu Picchu, Iguassu Falls in Brazil, and safari parks in eastern and southern Africa.

"We aren't trying to scare people away from traveling, but there are new and re-emerging diseases we need to do a better job of telling people about," says Phyllis Kozarsky, a CDC travel-medicine expert who also runs a travel clinic affiliated with Emory University in Atlanta.

The International Society of Travel Medicine, a nonprofit professional association, has been tracking trends in travel-related illnesses since 1997 with a grant from the CDC, based on data from 47 clinics in 23 countries. Of nearly 100,000 patients seen through last year, about 8% were U.S. residents. Acute diarrhea and malaria were the most frequent diagnoses, and the countries where illness originated most often were Mexico, India, Brazil, Peru and Ghana.

Companies that send employees overseas will typically cover the cost of consultations and recommended vaccines. But health plans often won't cover leisure-travel consultations or vaccines other than those recommended for patients as a matter of course in the U.S. Since vaccines can cost more than $100 each, that may deter travelers from seeking their own care.
Travelers can educate themselves about the risks and the types of preventive measures they need to consider at cdc.gov/travel. The site includes updates on outbreaks and countries that require certificates of vaccination for entry to certain regions. The travel medicine society, which certifies doctors and other clinicians in travel health, includes links to clinics on its ISTM.org Web site.


One area of mounting concern to public-health officials is the growing number of foreign-born U.S. residents and other immigrants who are traveling to visit family and friends in their native countries. Vaccinating a whole family can be costly. And travelers may mistakenly believe that neither they nor their children are at risk for diseases endemic in their home countries. In fact, these travelers may never have encountered diseases that are new to their country, and the children may have lived all or most of their lives in the U.S.

Likewise, some travelers throw caution to the wind in an effort to have genuine local experiences. "People do crazy things when they are on vacation and take risks they would never think of at home," says Fran Lessans, a nurse who is founder and chief executive of Passport Health, which operates 167 travel-medicine clinics around the U.S. and provides vaccination services to the federal government.

Recent patients at one of her clinics included a young couple who got typhoid fever after eating jerk chicken from a roadside stand in Jamaica. Travelers may also be secretive about their sexual encounters overseas, Ms. Lessans says, but it's important to take precautions such as the vaccine against sexually transmitted hepatitis B, which can lead to liver cancer.

Among the most worrisome trends is the spread of malaria to areas including Central America and the Caribbean. There is no vaccine against malaria, which in the past was most common in sub-Saharan Africa. The CDC recommends taking one of several kinds of antimalaria pills as a preventive measure, depending on the duration and location of the trip. Though the pills have side effects such as stomachaches, it is important to take them in countries where the disease is present and to seek medical care upon returning home with any unusual symptoms. While some cases are mild, malaria can also be deadly in as little as 24 hours, Dr. Kozarsky warns.



Dengue fever, which hadn't been a major problem since the 1960s, is re-emerging in places like Puerto Rico, the Caribbean and Central and South America. Unlike malaria, which is spread by mosquitoes that bite at night, dengue is also spread by day-biting mosquitoes, and malaria pills won't protect against it. There is no vaccine and no medication that specifically treats the disease, which can lead to a fatal hemorrhagic fever. The best preventive measure: an insect repellent containing an active ingredient like DEET and long-sleeved shirts and pants.

Newer threats include chikungunya fever, which started years ago in Africa but is now a risk in India, Bangladesh, Thailand and Singapore. It has been diagnosed in thousands of travelers returning to Europe and the U.S. in the last few years. Though rarely fatal, it can cause fever and joint and muscle pain that can cause arthritis-like symptoms for years. Like other diseases spread by mosquitoes, once someone is infected overseas, it can be spread back home when another mosquito bites that person and then transmits the disease.

"Faster patterns of travel and longer haul routes are facilitating more rapid spread of novel pathogens," says David O. Freedman, a professor or medicine and epidemiology at the University of Alabama at Birmingham and secretary of the International Society of Travel Medicine. "It's so much easier for diseases to spread because the bugs can move around the world much more quickly."

Scott Weisenberg, director of the NewYork-Presbyterian/Weill Cornell travel-medicine clinic, says travelers often need to use common sense, such as avoiding swimming in freshwater rivers and lakes in Africa, where parasites can wriggle into the skin and cause a nasty infection called schistosomiasis. And closed-toed shoes rather than sandals are recommended in parts of Central America, South America, India and tropical Africa to protect against tungiasis, an infestation by a form of sand flea that can burrow into the feet of travelers.

Dr. Weisenberg says each traveler has to weigh the risks, costs and benefits of pre-travel preventive measures -- as well as their own tolerance for risk. For example, when traveling to a country where there is a risk of getting liver disease caused by hepatitis A from food, one should consider that "while it isn't fatal it can make you very sick, and there is a good vaccine that is highly effective."

But the situation is different with the yellow fever vaccine, which can cause a bad reaction in a small number of people over age 60. Dr. Weisenberg says he would advise receiving the yellow fever vaccine to a person heading to West Africa in the rainy season. But if the patient was visiting Tanzania and staying on a cruise ship, it might not be worth the risk of side effects.
Travelers can obtain preventive care from their doctor or a private clinic. Passport Health charges $48 for a pre-travel consultation. It also offers vaccinations and kits that include medicine for diarrhea and a 12-hour controlled release mosquito repellent.


Drugstore retail walk-in clinics are also offering travel evaluations customized to a person's destination. Redi-Clinic, for example, with 22 locations in H-E-B grocery stores in Texas, charges $75 for a pre-travel evaluation and a kit with powerful insect repellents, an antibiotic, and antidiarrhea medications. Vaccines cost extra.

Even taking precautions, travelers can still get sick. Amy Labar, a 20-year-old student who spent her spring semester in Ghana, was struck with malaria in April, even though she had been taking preventive pills. Ms. Labar, now attending Haverford College in Pennsylvania, says the pills gave her side effects, including headaches and stomachaches, that were sometimes worse than the symptoms of the disease -- mostly fatigue. But unlike malaria, she says, "I knew the pills weren't going to end up killing me if I didn't do anything about it."

From The Wall Street Journal - The Informed Patient - June 10, 2009

Posted by Scott W. Yates, MD, MBA, MS, FACP