[1] Khon Kaen Univ, Fac Associated Med Sci, Med Diagnost Labs, Ctr Res & Dev, Khon Kaen, Thailand
[2] Minist Publ Hlth, Dis Prevent & Control Reg 10, Ubon Ratchathani, Thailand
[3] London Sch Hyg & Trop Med, Fac Infect & Trop Dis, Dept Immunol & Infect, London, England
[4] London Sch Hyg & Trop Med, TB Ctr, London, England