Indoor Residual Spraying (IRS) and Its Impact on Malaria Prevalence in West Africa Using the Panel Data Regression Model

Malaria remains one of the most important public health concerns across the globe. In 2012 alone, the World Health Organization reported an estimated 207 million cases and associated death of about 670,000 with majority of cases coming from Africa. There have been tremendous efforts at controlling malaria and its related mortality. The two main interventions recommended by the World Health Organization for malaria control and prevention are, Indoor Residual Spraying (IRS) and the use of Insecticides Treated Nets (ITNs). On a limited scope, studies conducted within some communities and limited geographical areas have shown the effectiveness of IRS in reducing the prevalence of the disease. However, not many such studies have looked at the impact of IRS on the prevalence of malaria at the universal level. This paper seeks to evaluate the impact of Indoor Residual Spraying on the prevalence of malaria in West Africa by accounting for the effects of alternative malaria prevention strategies, economic, demographic and funding availability for malaria prevention and control. A panel data for fifteen West African countries from 2008 to 2012 was analyzed. The results showed that for years in which Indoor Residual Spraying was implemented, prevalence of malaria reduced by 71% compared to periods preceding the implementation of Indoor Residual Spraying. This paper further established that ITN coverage, funding availability for Malaria intervention and gross domestic product have a significant negative impact on the prevalence of Malaria while population and the combination of Indoor Residual Spraying and ITN have a significant positive impact on the prevalence of the disease. Indoor Residual Spraying and its impact on the prevalence of Malaria were observed to be higher than the impact of ITN coverage on the prevalence of the disease. These findings are relevant for policy direction regarding the continuance of Indoor Residual Spraying implementation especially in the post 2015 agenda for malaria control and prevention.