1 Department of Internal Medicine Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia.
2 Education Development Center Department Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia.
3 Department of Microbiology Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia.
4 Department of Internal Medicine Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia; Department of Microbiology, Vestfold Hospital Trust, Tønsberg 3103, Norway. Electronic address: thor-henrik.henriksen@siv.no.