1. Biomedical Research and Clinical Trials Department, Ifakara Health Institute , Ifakara , Tanzania
2. Department of Medicine, Swiss Tropical and Public Health Institute , Allschwil , Switzerland
3. University of Basel , Basel , Switzerland
4. St Francis Regional Referral Hospital Internal Medicine Department, , Ifakara , Tanzania
5. Division of Infectious Diseases and Hospital Epidemiology, University Hospital, Basel , Basel , Switzerland