"Montezuma's revenge" is the most infamous vacation malady, but other ailments - both mild and life-threatening - are on the rise as exotic vacations have increased in popularity.

Before vacationing, Utah travelers should arm themselves with the right immunizations for their destination, said Rick Crankshaw, director of the Utah Department of Health Immunization Program."Even if no immunizations are required, you should know the risks of disease in the areas you are visiting and ask your doctor or local health department about precautionary shots or possible other medications beforehand."

Crankshaw warned that because medical facilities in foreign locales can be unfamiliar and inadequate, Utahns should take precautions against these current health hazards:

- Travelers' diarrhea: This ailment afflicts almost 40 percent of American visitors to Mexico; 30 percent of its victims must be confined to bed. Caused by various bacteria, viruses and parasites, it can usually be averted by avoiding uncooked foods, unwashed salads, unpeeled fruit, fresh milk, creamy desserts, pastries and sauces and unboiled tap water, including ice.

Crankshaw said various drugs can help prevent diarrhea, but cautioned against purchasing over-the-counter drugs in foreign countries because of less-stringent standards for approving and licensing medications abroad.

Sufferers should drink bottled water to prevent serious dehydration.

- AIDS: Travelers, especially to Africa, should be reminded of the risk of acquiring AIDS from unsterile injections, blood transfusions or sexual contacts.

- Measles: Anyone born after 1956 who has not been vaccinated and who has never had the illness should receive measles vaccine.

- Polio: Travelers to tropical or developing countries should get a dose of polio vaccine. Whether or not the person receives oral or injectable polio vaccine depends on his prior vaccine history.

- Tetanus and diphtheria: Whether traveling or not, everyone should receive vaccinations against these two diseases, and booster immunizations every 10 years.

- Typhoid: Immunization is recommended for travelers to rural areas of tropical countries, to areas with poor personal and public hygiene and if there is a recognized risk of being exposed to the organism.

- Yellow fever: Travelers to tropical South America and parts of Africa should receive an immunization.

- Malaria: Anti-malarial medications are advised before travel to rural areas of East and Central Africa, Southeast Asia (notably Thailand), the Amazon region of Brazil and East Africa. Most urban and tourist areas are at low or no risk.

- Hepatitis A: Travelers exposed to repeated poor hygiene and water - usually those who are advised to receive typhoid/diphtheria immunizations - should consider receiving immune serum globulin as well.

Crankshaw said women of child-bearing age should be sure they are also immune to rubella before traveling abroad.

"There are many factors involved in determining what immunizations or preventive medications are recommended for overseas travel," he said. "Not only the country of destination, but the type of travel and duration of stay are often considered in making recommendations." She advised that would-be travelers check with their travel agent, doctor or health department.