1. 1Department of Paediatrics, University of Malawi, College of Medicine, Blantyre, Malawi;
2. 2Department of Public Health, University of Malawi, College of Medicine, Blantyre, Malawi;
3. 3Clinical Department, Light House Trust, Kamuzu Central Hospital, Lilongwe, Malawi;
4. 4Department of Paediatrics, Queen Elizabeth Central Hospital, Blantyre, Malawi;
5. 5Karolinska Institutet, Department of Global Public Health, Stockholm, Sweden;
6. 6Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom;
7. 7Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden;
8. 8Karolinska Institutet, Department of Women's and Children's Health, Stockholm, Sweden;
9. 9Karolinska Institutet, Department of Clinical Science, Intervention and Technology, Huddinge, Sweden