The incidence of water-related diseases in the Brak area, Libya from 1977 to 1979, before and after the installation of water treatment plants.

The incidence of nine water-related diseases in the Brak oases of the Sahara desert, before and after the installation of water treatment plants, are reported. Immediately following installation of the plants there was a drop in the incidence of most of the water related diseases. There then followed a gradual deterioration in the treatment plants and within a year the incidence of four of the diseases was again rising. Furthermore neither malaria or giardiases showed any drop in incidence over the study period. Bacillary dysentary, infectious hepatitis and bilharzia did however drop significantly over the three years. A correlation between bacillary dysentary and the mean noon-time temperature for two of the three years was noted.