1. Department of Biomedical Sciences and Immunology, Natural Sciences College, Madda Walabu University, P.O. Box 247, Bale-Robe, Ethiopia
2. Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
3. Division of Epidemiology, Gambella Regional Health Bureau, Gambella Region, P.O. Box 408, Gambella, Ethiopia
4. Department of Public Health, College of Health Sciences and Medicine, Jimma University, P.O. Box 378, Jimma, Ethiopia
5. Department of Epidemiology, College of Health Sciences and Medicine, Jimma University, P.O. Box 378, Jimma, Ethiopia