MALARIA

Scope of the problem

Malaria is endemic to the poorest countries in the world, mainly in tropical and subtropical regions of Africa, Asia and the Americas . An estimated 300 million to 500 million clinical malaria cases and more than one million malaria deaths occur each year, the vast majority of which are in sub-Saharan Africa . More than 90% of malaria deaths occur in Sub-Saharan Africa and the large majority of these are in children younger than five years of age.

Children who survive malaria do not escape unharmed. Repeated episodes of fever and anemia take a toll on their mental and physical development, impairing their education, their growth into productive adults. Pregnant women and their unborn children are also particularly vulnerable to malaria, which is a major cause of low birthweight, anemia and infant death. Malaria has a devastating effect on adults, as well, because repeated infections drain their capacities.

Malaria costs Africa more than US$12 billion annually and thus, is a major factor contributing to erosion of development in some of the poorest countries of the world. Malaria has slowed economic growth in African countries by 1.3% per year.

The disease
Malaria is a disease of warm, humid climates where pools of water constitute perfect breeding grounds for the Anopheles mosquito. With the bite of the mosquito, malaria parasites are transmitted from infected to healthy people. Once in the bloodstream, the mature parasites reach the liver where they multiply. The rapid multiplication of the parasite causes the destruction of red blood cells and the infection of new cells throughout the body. Depending upon the species of infected Anopheles mosquito, the infected person will become ill with malaria after about a week to several months, but mostly within 7-21 days. Symptoms

The most important sign of malaria is fever. The symptoms in children and adults infected with malaria might also include shivering, severe pain in the joints, headaches, vomiting, generalized convulsions and coma, but also coughing and diarrhoea.

Early diagnosis and treatment saves lives and prevents the development of complications: A very high body temperature, drowsiness, convulsions and coma are indicative of cerebral malaria. Jaundice and reduced urine output are signs of liver and/or kidney failure. If children, in particular, are not treated within a day, the disease can lead to death. In most cases, severe anaemia is the attributable cause of death.

Pregnant women, together with young children, are especially vulnerable to malaria. The severe anaemia caused by malaria in pregnant women can result in miscarriage, premature or stillbirth. Babies born to women infected with malaria during pregnancy are likely to be small and weak, making them especially vulnerable to infections. These babies have an increased risk of mortality.

Prevention and treatment Insecticide-treated mosquito nets
Many studies have shown that sleeping under a mosquito net treated with insecticides that kill mosquitoes or stop them from biting is a powerful prevention against malaria.

These treated nets are low in cost and well accepted by the people who need them. By preventing malaria, insecticide-treated nets reduce the need for treatment and the pressure on health services.

Prevention during pregnancy

An estimated 10 000 pregnant women and up to 200 000 infants die each year as a result of malaria during pregnancy. Pregnant women living in places where malaria is highly prevalent are four times more likely than other adults to get malaria and twice as likely to die of the disease. Once infected, pregnant women risk anemia, premature delivery and stillbirth. Their babies are likely to be of low birth weight, which makes them unlikely to survive their first year of life.

Many malaria-endemic countries are taking steps to protect pregnant women: distribution of insecticide-treated mosquito nets and treatment during antenatal check-ups with drugs that prevent malaria infection (Intermittent preventive treatment or IPT).

More effective drug combinations

Since the 1980s, falciparum malaria has become increasingly resistant to commonly used single drugs such as chloroquine. This has emerged as a major challenge for delivering prompt effective treatment in many malaria endemic areas. Where current drugs used alone are failing, WHO recommends combinations of two or more effective drugs for treatment of malarial illness. Combinations of antimalarials containing an artemisinin compound (ACT) have shown a high level of efficacy in all malarious areas and, in addition, hold the promise of delaying the emergence of resistance.

* The Africa Malaria Report 2003, WHO/UNICEF