1. Africa Centre for Population Health, University of KwaZulu-Natal, Mtubatuba, KwaZulu-Natal, South Africa.
2. Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, California.
3. Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom.
4. School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Pietermaritzburg, KwaZulu-Natal, South Africa.
5. Research Department of Infection, University College of London (UCL), London, United Kingdom.