The effectiveness of the prevention and control methods applied towards the elimination of malaria in Botswana

Background: In 2008, the Ministry of Health (MOH) in Botswana was inspired by an overall decline of malaria prevalence within the population from 4.2% in 2000 to less than 1% in 2008. These results motivated the Government of Botswana to re-orientate strategy towards the elimination of malaria by 2018. Heavy rainfalls in 2017 led to an epidemic which caused a huge setback to their goal. This setback was especially due to the malaria cases reported in the South-East District, a region not classified as endemic in Botswana. This study examines the progress, effectiveness, and challenges of prevention and control methods for the successful elimination of malaria in Botswana. Materials & Methods Retrospective data about cases of malaria in Botswana covering endemic districts, and data about Indoor Residual Spray (IRS), Long -Lasting Insecticides Nets (LLINs) and larviciding from 2000 to 2018 were obtained from the Botswana MOH. Rainfall data from the Department of Metrological Services were also obtained. Intervention datasets were compared against rainfall amount and number of cases to establish their relationship. Results There is a significant difference between percentage of malaria incidence and percentage of mean annual rainfall in Botswana. A moderate positive correlation of 0.49 was reported with a p-value of 0.108 and t-value of 1.7652. Intensifying interventions in Botswana had no effect on number of cases based on this study. IRS coverage and intensity increased over years from 52.02% (2011) to 84.70% (2017), yet one heavy rainfall season resulted in increased cases of malaria in Botswana. Conclusions Improved forecasting can be used to predict malaria in Botswana, indicating malaria prevalence in Botswana is heavily dependent on the climate. IRS, LLINs, and larviciding should be carried out at the right time, not after mosquito numbers have increased and consistently without failure, to eliminate malaria. The steep decline in cases of malaria from 2000 to 2013 was likely due to the dry weather, not control methods applied.