World malaria situation, 1988. Division of Control of Tropical Diseases.

Indigenous malaria continues to occur in some 100 countries or areas. Excluding the WHO African Region where reporting is fragmentary and irregular, the trends in individual countries of the different regions vary, but an upward trend in the number of malaria cases reported in the Americas and some Asian countries, is clearly visible. Some 83% of the total number of cases reported annually to WHO (excluding the African Region) are concentrated in Afghanistan, Brazil, China, India, Mexico, the Philippines, Sri Lanka, Thailand and Viet Nam. Within these countries malaria shows a marked focalization. Of a total world population of about 5,061 million people (1988), 2,988 million (59%) live in areas free of malaria (it never existed, disappeared or was eliminated by antimalaria campaigns and the malaria-free situation has been maintained). 1,599 million people (32%) live in areas where endemic malaria was considerably reduced or even eliminated but transmission was reinstated and the situation is unstable or deteriorating. These areas include zones with the most severe malaria problems which developed following major ecological or social changes; these zones comprise only about 1% of the world population. Areas where endemic malaria remains basically unchanged and no national anti-malaria programme was ever implemented, are inhabited by 474 million people (9%), mainly in tropical Africa. In Africa south of the Sahara, 2-7 million cases are reported each year, but by extrapolating from fever and parasite surveys one can estimate that about 90 million clinical malaria cases may occur in tropical Africa every year, and that prevalence of infection may be in the order of 250 million parasite carriers. Endemicity reaches the highest levels in the world, with very large areas classified as holoendemic. Where endemicity decreases, marked seasonality and the quasi-cyclic occurrence of heavy rains lead occasionally to epidemics or serious exacerbations of endemicity. The lack or shortage of trained personnel for the planning, organization, monitoring and evaluation of programmes remains one of the major constraints in many countries. The policy advocated is the development of malaria control within the framework of primary health care at the district level. The aim is the prevention and reduction of malaria mortality by providing prompt diagnosis or recognition and adequate treatment of malaria cases through the basic health services and primary health care. This implies also the creation of efficient referral systems for the management of severe and complicated cases, and for treatment failures.(ABSTRACT TRUNCATED AT 400 WORDS)