Taking an assignment overseas? Before you go, learn how to reduce your risk of contracting infectious diseases.

At some point in your career, you may have the opportunity to take a nursing assignment abroad. Although this may be the opening you've been waiting for, it also may expose you to unexpected health hazards and travel-related illnesses.

Visiting underdeveloped countries increases your risk of contracting diseases that are uncommon in the United States, such as typhoid and yellow fever. Other possibilities include hepatitis, malaria, and meningitis-not to mention the routine health hazards of travel, such as jet lag, motion sickness, high-altitude sickness, and diarrhea.

How to prepare? Find out all you can about possible health risks in the area you plan to visit, and take every precaution. Check reliable online sources (see Selected Web sites at the end of this article). Be sure to review The Yellow Book: Health Information for International Travel, 2003-2004, which the Centers for Disease Control and Prevention (CDC) produces for health care professionals and posts online. For some basic tips on preparing for your trip, read on.

Best prevention: Get immunized

Contact your health care provider to ask whether you can get the immunizations you need at her office; like many providers, she might not stock the expensive immunizations there but refer you to a travel immunization clinic where you can get them. Run by state or local health departments, these clinics provide immunizations or can recommend someone who does (see the Travel Clinics page at the CDC's site).

Plan well in advance. Your body may need 4 to 6 weeks to reach full immunity with vaccinations. The vaccines you need depend on such things as how long you'll be gone, where you're going, and whether you'll be in rural or urban areas, where your risk for exposure can vary. How old you are is another factor. The CDC's guidelines for hepatitis A and B, meningococcal, rabies, and typhoid vaccines vary according to age.

Certain immunizations depend on diseases endemic to the areas you're visiting. For example, polio is still present in Asia and Africa, so you must have an updated adult polio booster before visiting there. Some countries in Africa or Central or South America require yellow fever vaccines to enter. For more information, see the Destinations page at the CDC's site.

If you get immunized at a travel immunization clinic, you may be asked to fill out a travel medical questionnaire about your allergies, current medications, and health history to help organize the screening process. Some clinics use special computer programs that help them identify the immunizations and medications you'll need, based on where you're going and how long you'll be traveling.

With each immunization, you'll be given a Vaccine Information Statement (VIS), as required by U.S. federal law. Prepared by the CDC, these information sheets explain the benefits and risks of a vaccine. You'll also get an International Certificate of Vaccination, a form approved by the World Health Organization (WHO) as the official document verifying that proper procedures were followed in administering vaccines for foreign travel. It's used to show that you've had the vaccines required by different countries, the date you got them, and who gave them to you. For example, the yellow fever vaccine requires a stamp, signature, lot number, date, and company name to satisfy entry requirements for countries that require this vaccination. Keep this booklet in a safe spot (it's designed to fit into a passport, which is a good place to keep it); losing it could prevent your entry into a country or require revaccination.

Practical prevention: Pack supplies

Tuck a supply of over-the-counter medicine in your carry-on luggage (or in your regular baggage if airline security guidelines specify that). Generally, packing some bandages, acetaminophen, ibuprofen, antibiotic ointment, diphenhydramine hydrochloride, and medication for diarrhea is smart. You also may want to add a thermometer, sunblock, and insect repellent. Carry an alcohol-based hand rub with you at all times.

Depending on your destination and plans, consider taking a portable water filter or iodine tablets with you so you can treat water on your own (or boil it for 10 minutes as an alternative).

Daily prevention: Avoid exposure

Although some diseases can be transmitted person-to-person through droplets from the nose and mouth, many are transmitted by water or mosquito bites. In underdeveloped countries with poor public sanitation and hygiene, unsuspecting travelers can easily get sick. Common hazards include severe diarrhea from bacterial infections caused by Cyclospora cayetanensis or been sickened by Escherichia coli, typhoid or hepatitis from drinking water and eating food contaminated with bacteria or parasites, and malaria from mosquito bites.

Unfortunately, vaccines aren't available for all diseases, including malaria and traveler's diarrhea, but you can lower your risk of exposure to many of these travel-related illnesses. Here's how:

* To prevent malaria: Wear clothing that exposes little skin to mosquitoes, use insect repellents containing DEET, take antimalaria pills, and sleep under mosquito netting.

* To prevent viral infections:

- Drink only canned or bottled carbonated drinks and water (make sure the bottled water is unopened to confirm that no one refilled an empty bottle with tap water). If you want a cold drink, ask for one that's been refrigerated rather than one chilled with ice cubes, which can be contaminated.

- Make sure the food you eat is thoroughly cooked and served piping hot. Avoid cold food, such as salads and uncooked vegetables. If you want some fruit, select something you have to peel, such as oranges or bananas; avoid fruits, such as apples or grapes, that may have been washed with contaminated water.

- Brush your teeth with bottled water and don't swallow shower water, which can be contaminated. Wash your hands in safe water or alcohol-based hand rubs.

Smart prevention: Stay informed

With ever-changing travel health issues (remember SARS?), make sure you get accurate up-to-date information just before you go. Stay tuned to the WHO and CDC sites, which include overviews of various geographic regions as well as alerts about any new outbreaks of infectious diseases. Be sure to follow the tips above so you're prepared to dodge those travel bugs.

SELECTED WEB SITES

Centers for Disease Control and Prevention: Travelers' Health: http://www.cdc.gov/travel

Destinations

http://www.cdc.gov/travel/destinat.htm.

National Center for Infectious Diseases

http://www.cdc.gov/travel/

Travel Clinics

http://www.cdc.gov/travel/travel_clinics.htm

Yellow book

http://www.cdc.gov/travel/yb/index.htm

World Health Organization

http://www.who.org

Last accessed on January 5, 2004.