Most travelers are aware of malaria’s dangers, but you may be more susceptible than you think.

David Riordan had been an expedition leader for six years before a bout with malaria in West Africa almost killed him. “My brain felt as if it would explode. My elbows hurt, my knees, my hips. It was painful even to sit up,” he recalls.

Riordan’s near-fatal mistake? He thought he could stop taking his malaria medicine for a brief time, to avoid building up a tolerance. “Very bad idea,” he says. Fortunately, thanks to prompt medical care, he recovered.

Malaria kills more than a million people every year. Presidents and popes—and even George Clooney—have all suffered from its debilitating effects. Though most travelers know to take antimalarial medication in high-risk zones, there’s more to preventing the disease than just swallowing a pill.

Malaria Where You Might Not Expect It

“If you want zero risk of malaria, there are some very nice places in Canada,” says Dr. Alan Magill, former president of the International Society of Travel Medicine. Beyond the well-known risks found in sub-Saharan Africa and the Amazon Basin, there are many places where you might be surprised to encounter malaria, such as parts of Mexico and Panama (see “Malarial Zones,” below). Also worth noting: the antimalarial medication that your travel medicine specialist prescribes will depend on where you’re traveling. To find a specialist near you, visit

You Might Be at Greater Risk

“Once you’re infected you’re going to get sick if you don’t have immunity,” Magill says. But even with treatment, the disease affects some travelers more severely. “At age 60 and above you’re at a much greater risk when dealing with malaria,” he continues. Children and people with suppressed immune systems, including pregnant women, are also more susceptible.

Deet Can Save Your Life

Forget the anti-Deet bias of the 1990’s. Nothing is better at repelling mosquitoes than this chemical, which the CDC has deemed safe and effective for use by adults. Also consider wearing clothing treated with permethrin repellent.

Time Is of the Essence

Riordan nearly died despite getting medical help quickly. I asked Dr. Magill what would happen if I got the disease and sweated it out for 10 days before coming to see him. “You’d be dead,” he said succinctly. Waiting even a few days is extraordinarily dangerous.

For anyone venturing to a high-risk destination, the threat of malaria is very real indeed. “Of all the things that one would do to prepare for travel,” Magill says, “avoiding malaria should be at the top of the list.”

Malarial Zones

The Centers for Disease Control & Prevention (CDC) maintains an online map of destinations with malaria risk. Some examples:

  • Parts of southern Mexico.
  • The Dominican Republic and Haiti.
  • Much of Central America and northern South America, especially the Amazon Basin.
  • Sub-Saharan Africa, except South Africa.
  • Most of South Asia and Southeast Asia, especially India.