ABSTRACT
During a severe drought Port-au-Prince, Haiti, lost hydroelectric power for 10 weeks. This led to water shortages in areas of the city dependent on water supplied from electrically driven pumps. In a study of the impact of water restriction on disease, 400 families were randomly selected from two urban areas differentially affected by the water shortage. Disease in children was found to be related to quantity of water used, socioeconomic status, employment of head of household, and family size. The methods used in this study are recommended for the investigation of the relationship between water quantity and health.
Subject(s)
Health Status , Health , Water Deprivation , Water Supply , Drinking , Family Characteristics , Female , Haiti , Humans , Male , Morbidity , Mortality , Socioeconomic Factors , Water Supply/standardsABSTRACT
A large-scale prospective study was designed to test the effects of aerial ultralow volume (ULV) application of malathion on epidemic Plasmodium falciparum malaria. The study was conducted during 1972 to 1973, in the Miragoane Valley of Haiti, an area having annual anticipated outbreaks of malaria, which allowed prospective assessment. Spraying of malathion at a dosage of 4.5 fluid ounces per acre reduced populations of adult Anopheles albimanus to less than 1% of prespray levels and interrupted epidemic transmission of P. falciparum malaria. No change was measured in susceptibility of the vector mosquito to malathion after six applications of spray during a period of 50 days. Ecologic study revealed no significant impact on nontarget vertebrates. Factors that contributed to the success of this method in Haiti were: 1) a susceptible population of mosquitoes; 2) suitable topography and climate conditions for spraying; and 3) treatment of an area sufficiently large to minimize the influence of immigration of mosquitoes from unsprayed areas.
Subject(s)
Disease Outbreaks/epidemiology , Malaria/prevention & control , Malathion/administration & dosage , Mosquito Control/methods , Plasmodium falciparum , Aircraft , Animals , Anopheles , Disease Outbreaks/prevention & control , Disease Reservoirs , Evaluation Studies as Topic , Geography , Haiti , Humans , Malaria/epidemiology , Malaria/transmission , Population Density , Prospective Studies , Research DesignABSTRACT
In the Miragoane Valley of Haiti a consistent pattern in the incidence of Plasmodium falciparum malaria over a 10-year period made it possible to predict an annual outbreak and perform a prospective study to test the effects of aerial ultralow volume (ULV) malathion on epidemic levels of this disease. At the end of October 1972, after epidemic levels (100 cases/month/10,000 population) had been reached, spray operations were begun. The first spray cycle produced a sharp and immediate drop in populations of the vector Anopheles albimanus, followed 4 weeks later by a decrease in the incidence of malaria throughout the valley. Although the incidence of malaria was similar in sprayed and unsprayed areas prior to the effect of ULV malathion (176.1 and 198.7 cases/month/10,000 population, respectively), it was significantly different during the subsequent 3 months (16.8 cases/month/10,000 population in sprayed areas and 65.4 in unsprayed; p less than 0.001). Travel histories indicated that only 4% of all cases had spent a night away from home during the 4 weeks prior to onset of symptoms; therefore, we concluded that these incidence data represent malaria transmission in the valley. Results of the study indicate that aerial spraying of ULV malathion can interrupt epidemic transmission of P. falciparum malaria by a susceptible vector.
