Quantitative estimates of the evolution of a malaria epidemic in Turkey if remedial measures had not been applied

Abstract

In 1978, public health authorities, by means of large-scale control operations, succeeded in containing a severe malaria epidemic that had reached alarming proportions in the Cukurova and Amikova plains of southern Turkey. The benefits derived from this intervention are indirectly quantified in this article by estimating the number of cases that would have ocurred in the area if remedial measures had not been applied.For this purpose a simple mathematical model was fitted to both the number of cases in January (seasonal minimum) and the number of cases in July/August (seasonal maximum) that were recorded during the years 1976, 1977, and the beginning of 1978; the incidence trend from 1978 onwards was then determined by projection. By this method, it was possible to estimate that in the absence of intervention the projected annual parasite incidence would have been 75.4 per 1000 in 1978 instead of the observed incidence of 24.5 per 1000. According to the forecast, this incidence would have reached 100.9 per 1000 in 1979, 115.1 per 1000 in 1980, to arrive at a final stable level of 129.4 per 1000, if intervention measures had not been applied.Comparison of the number of malaria cases actually detected in 1978 (70 468) with the number projected in the absence of intervention (226 252) seems to indicate that about 2/3 of the expected cases were prevented in 1978 by the remedial measures applied.