1. Institute of Medicine, University of Bergen, N-5021 Bergen, Norway
2. Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
3. Department of Bacteriology and Immunology, Division of Infectious Disease Control, Norwegian Institute of Public Health, Oslo, Norway
4. Department of Paediatrics and Child Health, Muhimbili National Hospital, Dar es Salaam, Tanzania
5. Department of Microbiology and Immunology, Muhimbili National Hospital, Dar es Salaam, Tanzania
6. Department of Medicine, Haukeland University Hospital, N-5021 Bergen, Norway
7. Department of Paediatrics and Child Health, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania