HEALTHY TRAVELER : Going Tropical? Get Hot Tips on Preventing Malaria

Travelers bound for tropical destinations often ask their physician the same questions during their pre-trip checkup:

How worried should I be about getting malaria? How can I prevent it?

There are no simple answers on how best to avoid malaria, travel medicine specialists say, or on gauging individual risk. The best answers, they say, require information about exactly where the travelers are headed, what they plan to do there and their medical history.

There was a risk of malaria, in varying degrees, in 100 countries and territories in 1997, according to the World Health Organization. The disease strikes 300 million to 500 million people each year, killing up to 2.7 million, according to WHO estimates.

Malaria is caused by parasites transmitted by the bite of an infected female Anopheles mosquito. One of these parasites, Plasmodium falciparum, can cause kidney failure, coma and death.

According to the federal Centers for Disease Control and Prevention, malaria occurs in many areas of Central and South America, sub-Saharan Africa, the Indian subcontinent, Southeast Asia, the Middle East and Oceania.

Educating travelers about how to protect themselves from the malaria-carrying mosquito is the first order of business, says Dr. John Horton, a Westlake Village internist with a special interest in travel medicine. “Try to prevent the bite,” he advises, adding that the malaria-carrying mosquitoes bite only during the night.

Horton recommends using an insect repellent containing DEET and using repellents containing permethrin on clothing, shoes, bed netting and gear.

Assessing the degree of risk depends on knowing the traveler’s itinerary, specialists say.

“If a traveler is headed to Peru, for instance, and will stay in the high country, he probably doesn’t need to take antimalarial medicine,” says Dr. Victor Kovner, a Studio City internist. If the traveler plans to visit the Peruvian jungle, however, Kovner would prescribe antimalarials.

Which antimalarial is best?

Chloroquine may be recommended for areas where the malaria is not chloroquine-resistant.

The adult dose is 500 milligrams of chloroquine (Aralen), according to CDC recommendations. An initial dose is taken a week or two before arrival in the malaria-prone area; then a tablet is taken once a week while there and for four weeks after departure. Side effects are rare, according to the CDC, but could include nausea, vomiting, headache, blurred vision and itching.

If travelers are going to an area where the malaria is chloroquine- resistant, the CDC recommends mefloquine (Lariam). The adult dose is a 250-milligram tablet taken at the same intervals as chloroquine.

Lariam use has become controversial in recent years, with grass-roots groups here and abroad warning travelers that the drug can cause long-lasting physical and mental side effects in some people.

Side effects from Lariam can include nausea, dizziness, difficulty sleeping and vivid dreams, according to the CDC, and, very rarely, more serious problems such as seizures, severe anxiety and hallucinations.

A test dose is often recommended one or two weeks before departure.

Certain travelers should not take Lariam, according to the CDC, including those who have had epilepsy or other seizure disorders, have a history of psychiatric disorder or have been prescribed medicine for an irregular heartbeat. To that list, Kovner adds travelers on antidepressants, acknowledging that he may be erring on the side of caution.

An alternative to mefloquine is doxycycline, which the CDC recommends beginning one or two days before travel to malarial areas. Other combinations of drugs may be recommended, depending on the destination.

Soon there may be other options. A new antimalarial drug, Malarone (atovaquone/proguanil), may be approved in a few months. A vaccine is under study but is probably several years from approval.

Healthy Traveler appears on the second and fourth Sundays of the month. Kathleen Doheny can be reached at kdoheny@compuserve .com.