1. Department of Public Health, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
2. Department of Environmental Health, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
3. College of Nursing, University of Saskatchewan, Saskatoon, Canada
4. School of Life Sciences and Bioengineering, Nelson Mandela African Institute of Science and Technology, Arusha, Tanzania