Baseline Malaria Prevalence at the Targeted Pre-elimination Districts in Ethiopia

Abstract

Background: Encouraged by the success in malaria control and prevention strategies, several malaria endemic countries have adopted elimination strategies worldwide. Accordingly, Ethiopian ministry of health launched malaria elimination with a stepwise approach by primarily targeting the low-transmission districts and their adjacent areas/zones in order to shrink the country’s malaria map progressively. Hence, this community survey was conducted to establish baseline malaria information at the preliminary phase of elimination for measuring future intervention success in elimination goal. Methods: Community based cross-sectional survey was conducted at twenty malaria elimination targeted districts selected from five regional states and one city administration in Ethiopia. The GPS enabled smart phones programmed with Open Data Kit were used to enumerate 9326 study households and collect data from 29,993 residents. Care Start™ Malaria HRP-2/PLDH Rapid Diagnostic Tests (RDTs) were used for blood testing at field level. Armpit digital thermometers were used to measure axillary temperature.Result: Overall malaria prevalence by RDTs was 1.17% (339/28973). The prevalence at district levels ranged from 0.0% to 4.7%. The total prevalence of febrile cases (axillary temperature >37.5oc) in the survey was 9.2% (2760/29993). Among the 2,510 febrile individuals tested with RDTs, only 3.35% (84/2510) were malaria positive. Among all study participants, 0.88% (255/28973) malaria positives were afebrile and 0.29% (84/28973) were febrile individuals. The 75.2% (255/339) of all malaria positives were afebrile. Of the total afebrile malaria cases, 10.2% (26/255) were under-five children and 89.8% (229/255) were above 5 years of age. Conclusion: The 1.17% malaria prevalence that ranges 0 to 4% in some districts by rapid diagnostic tests should be given due consideration by the elimination program. Especially the higher prevalence of afebrile individuals (0.88%) in these transmission settings indicates there may be sustaining hidden transmission. Therefore, active case detection with more sensitive diagnostic techniques than this conventional method is suggested to know more real magnitude of residual malaria in the elimination targeted low transmission areas and break the chain of transmission.