Reactive Case Detection of Malaria in selected Health Centers, Jimma Zone, Southwest Ethiopia

Abstract

Background: Malaria is a significant public health problem in Ethiopia with an estimated 75% of the land and 60% of the population being at risk of infection. In the last decade, malaria burden has dramatically decreased in several areas of the country, likely due to scale up of vector control interventions and early treatment approach. However, when malaria incidence decreased, residual transmission may occur even in areas with scaled up control interventions. Passive case detection (PCD) at health facility level alone may not have a significant impact in interruption of malaria transmission under such circumstances. The objective of this study was, therefore, to identify malaria cases and determine risk factors of Plasmodium infection among the study participants using Reactive Case Detection (RACD). Methods: A cross-sectional study was conducted from July to November 2016 in Kishe and Nada Health Center catchment kebeles, Jimma Zone, Southwest Ethiopia. Initially malaria cases (index cases) were identified at Kishe and Nada Health Centers by PCD. Following detection of the index cases, household members and residents in close proximity (200 meter radius) to the index households were screened for malaria infection. Microscopy and multi-species rapid diagnostic test (RDT) were used to detect Plasmodium species. Moreover, household and individual-level risk factors associated with Plasmodium infection were collected using semi-structured questionnaire. Data were analyzed using STATA12MP-1. Results: A total of 726 individuals were screened for malaria using RDTs and microscopy following 39 index cases. From these study participants, malaria cases detected by microscopy were 29(3.99) (3 P. vivax and 26 P. falciparum) and using multispecies RDTs were 33(4.55%) (3 P. vivax and 30 P. falciparum). The detection of malaria cases is higher among age groups of less than five years as compared to >15 age groups (AOR=3.1; 95%CI=1.20 - 8.17; p < 0.05). Fever (AOR=17; 95%CI=5.28 - 56.92; p < 0.05) and malaria history in the last one year (AOR= 4.3; 95%CI=1.90 - 9.91; p < 0.05) had also strong association with detecting malaria cases in the RACD method. Moreover, the odds of detecting malaria cases was higher in non sprayed houses than sprayed one. Presence of eaves and proximity to the index house were also strongly associatioted with the detection of malaria cases (AOR=4.5; 95%CI=1.49 - 13.67; p < 0.05and AOR=5.17; 95%CI=1.37-19.48;p < 0.05), respectively. Conclusion: Reactive case detection of malaria is promising method to detect additional malaria cases in the community, and identify reservoir infections and hotspots. Children under five years, fever, the previous one year malaria history, IRS status, distance from the index house and presence of eaves were associated with detecting additional malaria cases. The implementation of RACD could enhance malaria elimination program in Ethiopia but further studies are recommended.