Factors associated with severe malaria among children below ten years in Mutasa and Nyanga districts, Zimbabwe, 2014-2015

INTRODUCTION Severe malaria is a rare life threatening illness. Only a small proportion of patients with clinical malaria progress to this medical emergency. On reviewing 61 malaria death investigation forms submitted to the provincial office in 2014, 22(36%) were children below ten years who succumbed to severe malaria. Mutasa and Nyanga Districts reported 73% of these deaths. This study was conducted to determine factors associated with severe malaria so as to come up with evidence based interventions to prevent severe malaria and associated mortality. METHODS A 1:2 unmatched case control study was conducted. A case was defined as a child 10 years and below, who was admitted at Hauna (Mutasa) or Nyanga District Hospitals between September 2014 and May 2015 with a primary diagnosis of severe malaria. Controls were children of similar age with uncomplicated malaria. Permission to conduct the study was sought and granted by the Medical Research Council of Zimbabwe (Approval number B/874), Joint Research Ethics Committee, Health Studies Office and the Manicaland Directorate Institutional Review Board. Written informed consent was sought from all caregivers of enrolled children. Interviewer administered questionnaires were used to ascertain exposures. RESULTS A total of 52 cases and 104 controls were enrolled into the study. The median age of cases was 4 years (Q1=3, Q3=9) and 6 years for controls (Q1=3, Q3=8). The Case Fatality Rate among cases was 28.8%. The independent risk factors for severe malaria were; distance >10km to the nearest health facility [Adjusted Odds Ratio (aOR)=14.35, 95% CI=1.30, 158.81], duration of symptoms before seeking medical care >2 days [aOR=9.03, 95% CI=2.21, 36.93], having comorbidities [aOR=5.38, 95% CI=1.90, 15.19], staying in a house under construction [aOR=4.51, 95%CI=1.80, 11.32] and duration of illness before receiving antimalarial medicines >24 hours [aOR=3.82, 95% CI=1.44, 10.12]. Owning at least one ITN in the household [aOR=0.32, 95% CI=0.11, 0.95] and having a mother as a caregiver [aOR=0.23, 95% CI=0.09, 0.76] were independently protective of severe malaria. Being undernourished [Odds Ratio (OR)=10.13, 95% CI=1.04, 98.49] and being female [OR=0.27, 95% CI=0.08, 0.96] were associated with mortality owing to severe malaria. CONCLUSION Factors associated with severe malaria and mortality owing to severe malaria identified in this study are consistent with other studies. Caregiver healthcare seeking behaviours, patient related factors and health system related factors are important determinants of severe malaria among children. There is need for regular health education campaigns emphasizing on malaria prevention, signs and symptoms and benefits of seeking medical care immediately for sick children.