Matthew Rusk, M.D.
Malaria remains one of the most important and devastating infectious diseases in the world, and travelers to areas with malaria need to be prepared. Malaria is spread by the bite of a mosquito and avoiding insect bites is a vital part of avoiding the disease. Unfortunately mosquito bites may be unavoidable on certain trips. In this case, travelers must take medications to avoid malaria.
Avoiding Mosquito Bites
“In many parts of the world, the malaria parasite has become resistant to the older drugs used to prevent it….”
The risk of getting malaria is directly proportional to the risk of getting mosquito bites. Many of the species of mosquitoes that cause malaria are most active at dawn and dusk. Avoiding outdoor exposure at these times lowers the risk. Travelers should wear long pants and shirts with long sleeves. In areas of high risk, such as those traveling in jungle settings, it is advisable to soak clothing ahead of time in a solution of permethrin, which will repel mosquitoes for weeks. An insect repellent containing the ingredient DEET at concentrations of 30 to 35% should be applied to exposed areas of skin. Insect nets, which can be purchased at outdoor supply stores, should be purchased if sleeping quarters are not adequately screened or protected from the outside.
Medications to Prevent Malaria
Malaria can be effectively prevented with appropriate medications and mosquito avoidance. In many parts of the world, however, the malaria parasite has become resistant to the older drugs used to prevent it, and resistance patterns change frequently. For this reason, patients and their physicians should consult with either a travel medicine specialist or the Centers for Disease Control (CDC) for advice about the most effective malaria medications for their specific itinerary (regional malaria risk information, adapted from the CDC, is available within CityHealth Profiles). Here are three commonly used agents:
- Chloroquine. Travelers to Central America, north of the Panama Canal, can still use the old standby drug chloroquine. The drug must be started a week before the trip and taken weekly throughout the trip and for four weeks after return. While chloroquine is generally well tolerated, there are many possible side effects that patients should discuss with their doctors.
- Mefloquine. In much of Africa and Asia, the malaria species are more dangerous and generally resistant to chloroquine. Chloroquine resistance is also now widespread in the Western Hemisphere, south of the Panama Canal. In these areas the recommended drug is Mefloquine. While the drug can have some serious side effects, it has developed a bad reputation that is largely undeserved. Patients should review the risks but for most patients the benefits clearly outweigh them.
- Doxycycline. If mefloquine is not an option, then doxycycline is effective but must be taken every day rather than once a week.
- Atovaquone/proguanil. A new option is the more expensive combination drug atovaquone/proguanil, which was recently approved for use in the United States. Unlike mefloquine or doxycycline it does not have to be taken for four weeks after returning. It must be taken daily while traveling and continued for only seven days after returning.
While choosing the appropriate drug is important, it is equally important to take all of the medication as directed. In areas of high risk, not taking malaria medication for fear of side effects can lead to severe or fatal illness.