Effectiveness of seasonal malaria chemoprevention administered in a mass campaign in the Kedougou region of Senegal in 2016: a Case-control study

Context Seasonal malaria chemoprevention (SMC) with
Sulfadoxine-Pyrimethamine plus Amodiaquine (SPAQ) is a malaria prevention
strategy recommended since 2012 by the World Health Organization (WHO) for
children under 5 years of age. In Senegal, the scaling up of the SMC has
started since 2013 in the south-eastern regions of the country with an
extension of the target to 10 years old children. The scaling up of SMC
requires a regular evaluation of the strategy as recommended by the WHO.
This study was conducted to evaluate the effectiveness of SMC. 
Methodology  A case-control study was conducted in some villages
of the health districts of Saraya and Kedougou in the Kedougou region from
July to December 2016. A "case" was a sick child, aged 3 months
to 10 years, seen in consultation and with a positive RDT. The
"control" was a child of the same age group with a negative RDT
and living in the same compound as the case or in a neighbouring compound.
Each case was matched with two controls. Exposure to SMC was assessed by
interviewing the mothers/caretakers and by checking the SMC administration
card. Results A total of 492 children, including 164 cases and 328
controls, were recruited for our study. Their mean ages were 5.32 (+/-
2.15) and 4.44 (+/-2.25) years for the cases and the controls
respectively. Male children predominated in both cases (55.49%) and
controls (51.22%) (p=0.18). Net ownership was 85.80% among cases and
90.85% among controls (p=0.053). The proportion of controls who received
SMC was higher than that of cases (98.17% vs 85.98%; (p=1.10-7)). The
protective effectiveness of SMC was 89% (IC 95% =
84–93%) (OR=0.11). Conclusion  SMC is therefore an
effective strategy in the control of malaria in children. Case-control
studies are a good approach for monitoring the efficacy of drugs
administered during SMC.