Risk Factors Associated With Malaria Mortality in Tshwane District, South Africa: A Retrospective Cohort Study, 2011-2014

Background: Tshwane District in Gauteng Province identifies malaria cases from endemic provinces and neighbouring countries as well as Odyssean malaria cases. Objectives: To assess changes in malaria morbidity and mortality and to determine risk factors associated with malaria mortality in Tshwane District during 2011-2014.  Methods: A retrospective cohort study was conducted using malaria surveillance data collected by the Communicable Disease Control Directorate in Tshwane district over a period of four years. Only laboratory confirmed cases were enrolled in the study. Secondary death audits were reviewed. Logistic regression determined risk factors associated with malaria mortality.  Results: During 2011-2014, 964 cases were identified. Of these, the median age was 28 years (range: 4 months to 79 years), 71.7% (n=691) were males. The majority of cases, 96.6% (n=931), had travelled to malaria endemic areas within South Africa and neighbouring countries. Of those who travelled to endemic malaria provinces in South Africa, 62.5% (40/64) went to Limpopo. Malaria cases decreased from 333 in 2011 to 229 in 2014. There were 20 deaths (2.1%) and 19 (2.0%) Odyssean malaria cases. Age, gender and malaria season were not associated with mortality. History of travel to a malaria endemic area was a protective factor for mortality (aOR 0.2, 95%CI: 0.36 to 0.78, p=0.021). Conclusion: In this non-endemic district, a number of malaria cases have been reported. Public awareness regarding uptake of antimalarial prophylaxis before and during travel to endemic areas could lead to a reduction in mortality and morbidity in South Africa.