BACKGROUND ON MALARIA

Malaria, at one time extremely widespread, is now mainly confined to the poorer tropical areas of Africa, Asia and Latin America. In recent years malaria has reappeared in some areas where it had been previously eliminated. Globally, there are at least 300 Million acute cases of malaria each year resulting in over one million deaths. The great majority of malaria infections and deaths occur in Africa, south of the Sahara.

Malaria is caused by microscopic parasites (protozoa) which are transmitted from person to person by female anopheline mosquitoes. The male mosquitoes do not transmit the disease because they feed only on plant juice. There are about 380 different species of anopheline mosquito, of which 60 species are able to transmit the parasite. There are also four different species of malaria parasite which can infect humans. The most deadly (p. falciparum) is the dominant species in Africa, which explains in part the high death rate in this region.

When an infective anopheline mosquito bites a person, the malaria parasites are injected into the person with her saliva. The parasites travel through the bloodstream to the liver where they grow and divide, usually over a period of one to three weeks. After this stage, the new parasites produced in the liver re-enter the blood stream where they infect red blood cells and begin to multiply at a very rapid rate, destroying the cells they have infected. It is at this stage that the infected person begins to fall ill.

The first signs of malaria are a general feeling of being unwell, usually with fever, aching and often headache. Malaria may also cause a variety of other symptoms and has been nicknamed ‘the great imitator’. As a result malaria is easily confused with a variety of other common illness and not properly treated. Untreated malaria can lead to severe anaemia, organ damage, convulsions, coma and death. Malaria is diagnosed by the clinical symptoms, and when possible, microscopic examination of the blood. Uncomplicated malaria can normally be cured by antimalarial drugs, which may be obtained from health centres, pharmacies and shops. Unfortunately, in many areas the parasites have developed resistance to the most widely available and low cost drugs. Patients in these areas require treatment with more expensive antimalarial drugs or drug combinations. Patients with severe disease require hospital care.

Technological innovations in the 1930s and 1940s, namely the discovery of chloroquine, a low cost antimalarial drug, and the insecticidal properties of DDT, led experts to believe that malaria could be eradicated. Between 1955 and 1969, malaria eradication campaigns based on indoor house spraying with DDT, chloroquine treatment and active case surveillance eliminated or dramatically reduced the disease in North America, Europe, the for Soviet Union and areas of Asia and Latin America. In Africa malaria eradication efforts were initiated in only a few countries which adequate infrastructure development and resources to support the campaigns. It was intended that other African countries would begin eradication when infrastructure and resources were in place. Unfortunately, before this could happen, parasite resistance to chloroquine, mosquito resistance to DDT and loss of confidence in the campaign strategy resulted in the abandonment of the malaria eradication effort.

International interest in and funding for malaria research and control as well as social sector spending in many countries declined during the 1970s and 1980s. As a result the burden of malaria has been increasing and the disease has re-emerged in areas thought to be malaria free. This has been exacerbated by increasing resistance of the parasites to chloroquine and other antimalarial drugs, deterioration of health care and related infrastructures, migration, climate changes and changes in land use and settlement patterns. Against this dark background progress, both scientific and programmatic, continued to be made in some areas.

By the early 1990s, the international community recognized that complacency about malaria had lasted too long and the resurgence of the disease could be halted and the burden dramatically decreased. To achieve this would require strengthening of health systems, involving communities in the local adaptation, promotion and use of the available technology, and significant new investment in research. During the 1990’s enthusiasm for this approach grew, as did regional and nation capacity to undertake a renewed attack on malaria. This led to the launch of Roll Back Malaria in 1997.