Moving towards malaria elimination: trends and attributes of cases in Kavango region, Namibia, 2010-2014

Setting: Kavango, a 'moderate' transmission risk region located in north-eastern Namibia, borders Angola, a country with higher malaria transmission levels. Objective: To determine 1) the trends in malaria incidence between 2010 and 2014 in Kavango, 2) the socio-demographic and clinical characteristics of confirmed cases in 2014, and 3) associated risk factors of cases classified as imported. Design: This was a retrospective study of malaria case investigation forms conducted in all 52 public health facilities in 2014. Incidence was derived from aggregate routine surveillance data from the Health Information System (HIS). Results: During the 5-year study, incidence fell from 53.6 to 3.6 cases per 1000 population, then increased again to 47.3/1000. Fifty-five per cent of cases were males, and 49% were aged between 5 and 17 years. Of the 2014 cases, 23% were imported, and were associated with higher odds of severe malaria (adjusted odds ratio [aOR] 1.8; 95%CI 1.01-3.29), not having long-lasting insecticide treated nets (aOR 2.1, 95%CI, 1.3-3.4) and not receiving insecticide residual spraying (aOR 3.2, 95%CI, 2.1-5.1). Conclusion: Sporadic outbreaks in the 5-year period posed a threat to malaria elimination. Better targeting of vector control interventions, strong cross-border collaboration and robust health promotion will be key to achieving malaria elimination.