The impact of vector control measures on malaria epidemiology in Dar es Salaam

Abstract

A study on the impact of vector control measures on malaria epidemiology, before and after intervention measures were applied, 'was conducted in Magomeni in Dar-es-Salaam between October 1988 and April 1989. The study involve~ determining the prevalence rate of malaria by parasite and spleen rates, using children aged between 2-~ years old living in the study area, and comparing it with that of a control area. The main obj ecti ve of the study was to determine the prevalence of malaria before and after intervention and the effectiveness of the anti-vector measures of the malaria control programme in Magomeni. The study revealed that the prevalence of malaria in the study area was 20% before intervention and 19.7% six months after intervention. There was no statistically significant decrease in malaria prevalence six months after intervention measures were instituted. The spleen rate was not found to have significantly decreased after intervention. It was also found that Anopheles larval densities in the breeding sites in the study area were still high despite the application of the larvicide, 50% (Ee) r'e>ni trothion. However, it was observed that there was a gradual decrease in larval densities over the six month period in both the study and comparison areas.

iv Clinical malaria patients who were attending treatment in the health institutions in the study area before intervention constituted 18% of all out-patient attendances but six months later after intervention, the number decreased to 16%. However, the drop was not Despite this drop, malaria highest percentage of out- statistically significant. still consti tuted the patients. Therefore the study revealed that the malaria vector control measures that were carried out in the Magomeni area of Dar-es-Salaam over a period of six months had no significant impact on the epidemiology of malaria. The study, therefore, failed to support the -Null-hypothesis that the prevalence of malaria would drop• from a higher level of endemicity to the next lower level after six months of anti-vector operations.