Challenges Facing Antimalarial Therapy in Africa

Abstract

In Africa south of the Sahara, malaria remains the most prevalent disease with which individuals and health care systems must contend. The enormity of the impact of malaria on the quality of life and survival and on the socioeconomic development of African nations has created an urgent need for effective and sustainable control strategies [1,2]. To date, malaria control programs have evolved as an amalgam of existing practices, with considerable variations in application in different regions and countries. Experience reveals, however, that many malaria control practices are based on an epidemiologic understanding of malaria in Africa that is incomplete and certainly changing. South of the Sahara, Plasmodium falciparum, the most malignant of the four human malarias, constitutes 9096-95 96 of all malaria transmitted. The transmission of P. falciparum parasites is highly variable in these areas. Studies conducted in the 1980s in both East and West Africa have documented settings in which human populations are exposed to 200-300 infective mosquito bites annually, the most intense risk of infection ever documented [3,4]. Yet, while there are vast areas of Africa where P. falciparum transmission is intense and perennial, a substantial proportion of Africans live in settings where transmission risk is much lower and seasonally circumscribed. The encroachment of the Sahara has transformed extensive areas from regions of intense transmission to areas with transmission only in association with short and often unpredictable rainfall. Historically, malaria has been mainly a rural health problem in Africa, but larger urban areas are now increasingly plagued by malarial transmission [5]. A recent analysis illustrates the striking trend toward urbanization by African populations. By the year 2020, almost 5096 of the projected 1.1 billion Africans will live in urban areas [6]. Urban dwellers previously not at risk of malaria will have to contend with the full range of health consequences of P. falciparum infection.