Impact of scaling up malaria control interventions by targeting people of highest needs from 2005 to 2010 in Senegal
Since 2005, Senegal has scaled up malaria control interventions nationwide, mainly by an approach that allowed reaching people of highest needs. Activities have included vector control interventions such as Insecticide Treated Nets (ITN) and Indoor Residual Spraying (IRS), prevention of malaria in pregnant women, and diagnosis and treatment with an effective anti-malarial. This study aim to evaluate the impact of malaria interventions on all cause mortality among children under five years following the approach of targeting people of highest needs while scaling up of malaria control in Senegal. A “pre/post” study design following the recommendations of the RBM Monitoring and Evaluation Reference Group (MERG) was used. This assessment of the impact of the scalingup of malaria control interventions is based on a plausibility argument. Given that it is difficult to measure mortality resulting from malaria, the objective of the plausibility argument is to demonstrate the association between the scaling-up of malaria interventions and the reduction of all-cause mortality in children under 5 years of age in Senegal. Efforts in vector control led to an increase in the availability of resources, and substantial improvement in intervention coverage. Use of ITN by children under 5 increased from 7 per cent to 35 percent (p<0.001). The greatest increases were observed among populations most at risk of malaria, namely the poorest two quintiles, southern and central regions. Parasite prevalence decreased significantly from 6 per cent in 2008 to 3 per cent in 2010 (p< 0.001). The greatest reductions in anemia and parasitaemia were observed in populations from rural areas, the poorest populations, and populations from the central and southern epidemiological zones, who also displayed the highest increase in ownership and use of ITNs. All-cause under 5 mortality decreased by 40 per cent. Kaplan-Meier survival analysis showed better child survival over the period 2005–2010 compared to 2000–2005. Except for the region of Dakar, child survival estimates were higher in areas with the lowest prevalence of malaria. In addition, All-cause mortality in children under 5 years was significantly lower during the period after the scaling-up of malaria control interventions (OR: 0 63; 95% CI: 0.46–0.86). Other factors that might affect malaria transmission and child mortality were controlled for in the analysis. Despite increased rainfall malaria morbidity decreased, most strikingly among populations in which access to and use of ITNs increased most. While mortality declined in general during the study period, the greatest decreases in both parasitemia and child mortality were observed among the same populations that had the greatest increase in coverage of malaria control interventions. Similarly, the biggest declines in mortality occurred among the age group most likely to die of malaria, suggesting that malaria control interventions contributed substantially to the decrease in malaria morbidity, and consequently, to all-cause under 5 mortality. Based on the LiST model, the scaling-up of ITNs and IPTp from 2004–2010 averted 5,774 deaths in children under 5. The advent of home-based management to deliver malaria care at home, even in difficult to access rural areas, where the largest number of deaths usually occurs, has greatly contributed to expanding malaria case management across Senegal. All-cause mortality in children under 5 was significantly lower in the period after the scale up of malaria control interventions by targeting people of highest needs. The declines in mortality were greater in the populations and regions where coverage of malaria interventions was highest. The associations held even after taking into account other contextual factors. We drawn the conclusion that malaria control activities reduced malaria related morbidity and mortality, thus contributing to significant declines in all-cause child mortality between 2005- 2010 in Senegal.