Overview of Malaria

Today some 40 percent of the world’s population is at risk of malaria and the vast majority live in the world’s poorest countries. The disease is found throughout the tropical and subtropical regions of the world and causes more than 300 million acute illnesses and at least one million deaths each year. Ninety percent of these deaths occur among children under age five in sub-Saharan Africa; malaria kills an African child every 30 seconds. Those who survive an episode of severe malaria may suffer from a range of physical and mental disabilities.

Malaria is a parasitic disease that is transmitted between humans through the bite of the female Anopheles mosquito. While there are four types of parasites that can cause malaria in humans, Plasmodium falciparum is by far the most deadly and common, particularly in Zambia and throughout sub-Saharan Africa. Once a person is bitten by a P. falciparum-carrying mosquito, the parasite grows, multiplies, and undergoes a series of complex life cycle changes that allow it to evade the immune system and infect the liver and red blood cells. Additional changes taking place over the course of 10-18 days after initial human exposure to the parasite cause it to develop into a form that makes it possible for the human host to transmit the parasite to the next biting mosquito.

Malaria disease caused by P. falciparum may result in death within hours or a few days of infection especially in those with low immunity such as children, pregnant women, people with AIDS (not necessarily HIV carriers), and travelers from areas with little or no malaria. Malaria can also result in miscarriage in pregnant women, low birth-weight infants, developmental disabilities, and other complications.