M4ALARIA is a complex disease that requires an association of three factors-parasite, vector, and host-to continue its life cycle. The physical and cultural environments in Bangladesh permit the survival of at least two malarial parasites, Plasmodium malariae and Plasmodium falciparum, and three vectors, A. philippinesis, A. sundaicus, and A. minimus, during most of the year.' Bangladesh is considered a malaria-endemic area, and some parts of the country have been designated as hyperendemic.2 Before the introduction of the Malaria Eradication Program (MEP) in 1961, the disease was so widespread that it accounted annually for 15 percent of the total deaths in Bangladesh.3 The annual incidence of malaria has been greatly reduced by MEP.4 Although uniform data are not available for the early years of the program, governmental documents published in the late 1960s reported a remarkable decrease in the number of malaria cases after the institution of MEP.5 The decline was particularly striking for the years 1968 to 1971 (Fig. 1). The incidence of malaria dropped from 10.8 per 100,000 population in 1968 to 4.22 per 100,000 in 1971. A reverse trend marked the period 1972-1977, which was characterized by a rise from the 4.22 per 100,000 in 1971 to 25.40 in 1972. A slight drop in the rate occurred in 1973, but it rose to a peak of 60.44 in 1976.6 The drop to 35.87 the following year did not necessarily indicate the beginning of a downward trend in the number of reported cases of malaria, because the two-year plan which was implemented in 1978 did not allocate funds for the MEP. In a subsequent five-year plan for 1980-1985, the program received 6 percent of the total health budget.7 The incidence of malaria in Bangladesh was much higher in the years 1972-1977, which I term hereafter the resurgence period, than in the years