[1] Univ London Imperial Coll Sci Technol & Med, Dept Biochem, London SW7 2AZ, England
[2] Univ Oxford, John Radcliffe Hosp, Nuffield Dept Clin Med, Ctr Trop Med, Oxford, England
[3] Cho Quan Hosp, Ctr Trop Dis, Ho Chi Minh City, Vietnam
[4] Cho Quan Hosp, Wellcome Trust Clin Res Unit, Ho Chi Minh City, Vietnam
[5] Univ Med & Pharm, Ho Chi Minh City, Vietnam
[6] Dong Thap Prov Hosp, Dong Thap, Vietnam