[1] Guys & St Thomas Natl Hlth Serv Fdn Trust, Directorate Infect, London, England
[2] Guys & St Thomas Natl Hlth Serv Fdn Trust, Intens Care Unit, London, England
[3] Kings Coll London, Dept Infect Dis, Sch Med Guys, London WC2R 2LS, England
[4] St Thomas Hosp, London, England
[5] Mahidol Univ, Fac Trop Med, Mahidol Oxford Trop Med Res Unit, Bangkok 10700, Thailand