Malaria is a concern for travelers who venture where the Andes slope into the Amazon below about 1,500 meters. There is a much greater chance of getting malaria in the jungle of northern Peru, such as in the surroundings of Tarapoto, the Reserva Nacional Pacaya Samiria, or Iquitos, than there is in the southern jungle of Parque Nacional Manu and Puerto Maldonado area.

The four species of parasite that cause malaria are all transmitted by a female mosquito, which bites most frequently at dawn and dusk. Symptoms include chills, sweats, headaches, nausea, diarrhea, and especially spiking fevers. We recommend that travelers heading to the Amazon protect themselves from mosquito bites and take antimalarial medicines.

Peru’s mosquitoes, affectionately known as the Bolivian air force, have developed a resistance to chloroquine, the traditional malaria medicine. So that leaves three medicines available to travelers: Mefloquine is taken weekly both before and after leaving the jungle, but it has a host of side effects. Malarone is a new drug that is taken daily and has few side effects but is very expensive. And then there is doxycycline, which is also taken daily but is very cheap. Doxycycline’s side effects can cause upset stomach and make your skin sensitive to sunlight.

Unfortunately, none of these medicines are completely effective, and many have contraindications. Consult your doctor about which is most appropriate for you. After returning from the jungle, finish your malarial meds completely. Malaria symptoms can take months to appear, and you should see your doctor if you experience fevers after your return from Peru. More information is available in the United States through the CDC’s hotline (tel. 877/394-8747).