[1] UCL, Dept Infect & Populat Hlth, London WC1E 6JB, England
[2] Brigham & Womens Hosp, Div Global Hlth Equ, Boston, MA 02115 USA
[3] European Ctr Dis Prevent & Control, Microbiol Coordinat Sect, Stockholm, Sweden
[4] Ctr Infect Dis Surveillance & Control, Publ Hlth England, Lab Healthcare Associated Infect, London, England
[5] Ctr Infect Dis Surveillance & Control, Publ Hlth England, Modelling & Econ Dept, London, England
[6] Ctr Infect Dis Surveillance & Control, Publ Hlth England, Bioinformat Unit, London, England
[7] London Sch Hyg & Trop Med, Dept Infect Dis Epidemiol, London WC1, England
[8] Queen Marys Univ, Ctr Primary Care & Publ Hlth, London, England
[9] Natl Ctr Emerging & Zoonot Infect Dis, Ctr Dis Control & Prevent, Atlanta, GA USA
[10] Univ Bern, Inst Social & Prevent Med, Bern, Switzerland
[11] Imperial Coll London, Sch Publ Hlth, London, England