1 Biomedical Research and Training Institute, Harare, Zimbabwe; Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK. Electronic address: ioana-diana.olaru@lshtm.ac.uk.
2 National Microbiology Reference Laboratory, Harare, Zimbabwe.
3 Department of Clinical Sciences, Liverpool School of Tropical medicine, Liverpool, UK; Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.
4 Biomedical Research and Training Institute, Harare, Zimbabwe; Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK.