What is Malaria?

It is a serious tropical disease caused by infection with one of four species of the Plasmodium protozoa that infect humans: P. falciparum, the most often fatal form; and P. vivax, P. ovale, and P. malariae, all of which cause more benign disease. Malaria is most commonly transmitted through the bite of an infected Anopheles mosquito. It can also be transmitted by contaminated needles or blood transfusion and during pregnancy. Malaria is a major health problem in areas of the world inhabited by over 40% of the world population. It is responsible for over 1 million deaths per year. It is the most frequent infectious cause of death for persons traveling to countries in the tropics and subtropics.

What are the symptoms?

The infection initially causes flu-like symptoms with fever, muscle aches, nausea, and fatigue. More severe forms of the disease progress to organ failure, coma and death. Infection with the more benign species can produce the classical course of recurrent bouts of fever, chills and aches alternating with symptom free periods.

The incubation period (the time between infection and the first symptoms) can be as little as 8 days or as long as 8-9 months depending on the infecting strain.

Who is at risk?

Like many travel health concerns the risk will vary depending on destination, itinerary, season and style of travel. In general malaria is a risk in rural and urban areas in sub-Saharan Africa and the Indian subcontinent. In most other risk areas of the world, malaria transmission occurs only in rural areas. Risk increases with rainfall and warmer temperatures and decreases with altitude. The Anopheles mosquito feeds mainly from dusk to dawn, so risk also depends on evening and nighttime outdoor activities and sleeping accommodations.

How do I protect myself?

Malaria prevention is a combination of avoidance, mechanical protection and chemoprophylaxis (the administration of medications for the prevention of infection or disease). No method can protect completely against the risk of contracting malaria. There is currently no vaccine available to prevent malaria.

• Avoidance - know your enemy. Be aware of the behavior of the Anopheles species in your location. Where do they like to breed? Where and when do they like to feed?

• Mechanical protection - physical and chemical barriers between you and them.

  • Protective clothing - long sleeved shirts and long pants in light colors.

  • Insect repellent - apply to all exposed skin and thin clothing according to the manufacturer's instructions.

  • Getting ready for bed - if rooms are not air-conditioned or adequately screened use a treated bed net and tuck the edges under the mattress.

• Chemoprophylaxis - an anti-malarial medication regimen is recommended for all travelers who will be in a malaria risk area with exposure between dusk and dawn. Which drug you use will depend on your location, your medical history and personal preferences.

The table below lists the most common medications used for chemoprophylaxis in the U.S., their potential side effects, regimen and relative cost.