PDF《ORIGINAL: ENGLISH》

90 countries worldwide. According to figures provided by the World Health Organization (3), 36% of the global population live in areas where there is risk of malaria transmission, 7% reside in areas where malaria has never been under meaningful control, and 29% live in areas where malaria was once transmitted at low levels or not at all, but where significant transmission has been re-established (3). The development and spread of drug-resistant strains of malaria parasites has been identified as a key factor in this resur- gence and is one of the greatest challenges to malaria control today. Although there is currently an increase in attention and resources aimed at malaria, including such initiatives as Roll Back Malaria (4), the Multilateral Initiative on Malaria FIGURE 1. APPROXIMATE DISTRIBUTION OF MALARIA

3 WHO/CDS/CSR/DRS/2001.4 DRUG RESISTANCE IN MALARIA attributed to malaria each year occur in African children (3). Other estimates based on a more rigorous attempt to calculate the burden of disease in Africa support this level of mortality (7). In addition to its burden in terms of morbidity and mortality, the economic effects of malaria infection can be tremendous. These include direct costs for treatment and prevention, as well as indirect costs such as lost productivity from morbidity and mor- tality, time spent seeking treatment, and diversion of household resources. The annual economic bur- den of malaria infection in

1995 was estimated at US$ .8 billion, for Africa alone (8). This heavy toll can hinder economic and community development activities throughout the region. Malaria transmission occurs primarily in tropi- cal and subtropical regions in sub-Saharan Africa, Central and South America, the Caribbean island of Hispaniola, the Middle East, the Indian subcon- tinent, South-East Asia, and Oceania (figure1). In areas where malaria occurs, however, there is con- siderable variation in the intensity of transmission and risk of malaria infection. Highland (>

1500 m) and arid areas (90% ? Quantification of parasitaemia aids training and supervision for reliable 0.08** ........