1. Unidad de Epidemiologia y Bioestadistica, Hospital Clinic/IDIBAPS, Barcelona, Spain
2. Ifakara Health Research and Development Centre, National Institute for Medical Research, Ifakara, Tanzania
3. Saint Francis Designated District Hospital, Ifakara, Tanzania
4. Swiss Tropical Institute, Basel, Switzerland
5. London School of Hygiene & Tropical Medicine, London, UK
6. National Institute for Medical Research, Dar es Salaam, Tanzania
7. District Medical Officer, Kilombero, Tanzania