What is malaria?

Malaria is an infection that causes high fevers and shaking chills. It's spread by a mosquito that feeds at night. The mosquito carries a parasite (“bug”) that causes malaria. If this mosquito bites you, the bug can get into your blood. The bug turns into many bugs, and they feed on your blood cells until you get very sick. Some people even die from malaria.

Where is malaria most common?

Malaria is a big health problem in many tropical countries. It's even a problem for people visiting these countries. Your chance of getting malaria is highest when you travel in New Guinea, the Solomon Islands, African countries south of the Sahara Desert and some remote places in southeast Asia. Your chance of getting malaria is a little lower in the areas around the Amazon River in South America, in India and in some rural areas of Central America. In many countries in Asia and South America, malaria is only in the countryside. If you travel to these countries, you may not need to take malaria medicine if you stay in the malaria-free big cities or only take day trips outside the cities.

How can I protect myself from getting malaria?

You should do whatever you can to keep from getting mosquito bites. If you can, sleep in a room with screens on the windows and doors. Use a mosquito net over your bed. If possible, spray the net with permethrin. (Permethrin is a spray that repels mosquitos.) During the evening, wear light-colored clothes with long sleeves. It's important to protect yourself with a bug repellant spray that contains no more than 35 percent of a chemical called “deet.” Try not to go outside after the sun sets.

What medicines can I take to prevent malaria?

If you plan to travel to a country where malaria is common, you'll probably take a medicine that may keep you from getting malaria. This is called “prophylactic” malaria medicine. Remember, though, no medicine can protect you from malaria 100 percent.

The medicine to use for travel in most areas is mefloquine (brand name: Lariam). You start taking it one week before you leave on your trip. You take the medicine once a week during your trip. Then you keep taking it once a week for four weeks after you get home. It's very important to keep taking the medicine after your trip, because the malaria bugs could still be in your blood. Stopping the medicine too soon could give the bugs a chance to grow and make you sick. The medicine has some side effects, and not everyone can take it. Your doctor can tell you if you can take mefloquine.

If you (or a family member) can't take mefloquine, you might take doxycycline (brand name: Vibramycin). You have to take this medicine every day. You start taking it a few days before you leave for your trip. You take it every day while you're gone. Then you take it every day for four weeks after you come home. Doxycycline makes you sunburn easily, so you must wear a hat, long sleeves and sunscreen whenever you're outside during the day. Some people can't take this medicine. Your doctor can tell you if you can take doxycycline.

If you're traveling to parts of Central America, Haiti or the Middle East, you may be able to take chloroquine (brand name: Aralen). You take this medicine once a week, just like mefloquine. Your doctor can tell you if you should take chloroquine.

Where can I get more information about malaria and travel?

To find out about the malaria risk for every country, check the Centers for Disease Control and Prevention (CDC) Web site (http://www.cdc.gov), or call the CDC at 1-888-232-3299.

This Web site offers useful travel information—Shoreland's Travel Health Online (http://www.tripprep.com).

If you plan to be in an area where the risk of getting malaria is high, you should contact a travel medicine clinic before you leave home. For a list of travel clinics, call the International Society of Travel Medicine at 1-770-736-7060 or visit their Web site (http://www.istm.org).