2 Oxford University Clinical Research Unit, Ho Chi Minh, Viet Nam.
3 University of Medical Technology and Pharmacy, Da Nang, Viet Nam.
4 University of Science and Technology, Da Nang, Viet Nam.
5 Hospital for Tropical Diseases, Ho Chi Minh, Viet Nam; Department of Health, Ho Chi Minh, Viet Nam.
6 Oxford University Clinical Research Unit, Ho Chi Minh, Viet Nam; Nuffield Department of Medicine, Centre for Tropical Medicine, University of Oxford, UK.
7 Oxford University Clinical Research Unit, Ho Chi Minh, Viet Nam. Electronic address: tanlv@oucru.org.