1 National Hospital of Tropical Diseases, Dong Da, Hanoi, Vietnam.
2 Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam; Nuffield Department of Medicine, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DU, UK; Radboud Medical Centre, Radboud University, Nijmegen, Netherlands.
3 Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam; Nuffield Department of Medicine, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DU, UK.
4 Medical Services Administration, Ministry of Health, Ba Dinh, Hanoi, Vietnam.
5 Nuffield Department of Medicine, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DU, UK; National Infection Service, Public Health England, London, UK.
6 Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam; Nuffield Department of Medicine, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DU, UK. Electronic address: rvandoorn@oucru.org.