1. Department of Bacteriology and Immunology Norwegian Institute of Public Health Oslo Norway
2. Department of Community Medicine Section of International Community Health University of Oslo Oslo Norway
3. Arba Minch College of Health Sciences Arba Minch Ethiopia
4. Armauer Hansen Research Institute Addis Ababa Ethiopia
5. College of Medicine and Health Sciences Arba Minch University Arba Minch Ethiopia
6. Arba Minch General Hospital Arba Minch Ethiopia