1 Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi, The College of Medicine, Blantyre, Malawi; Queen Elizabeth Central Hospital, Blantyre, Malawi. Electronic address: kathrynhaigh@nhs.net.
2 Queen Elizabeth Central Hospital, Blantyre, Malawi.
3 Public Health Institute of Malawi, Ministry of Health, Lilongwe, Malawi.
4 Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi, The College of Medicine, Blantyre, Malawi; Department of Microbiology, University of Malawi, The College of Medicine, Blantyre, Malawi; Liverpool School of Tropical Medicine, Liverpool, UK.
5 Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi, The College of Medicine, Blantyre, Malawi; Liverpool School of Tropical Medicine, Liverpool, UK.