[1] Free Univ Brussels, Erasme Hosp, Dept Intens Care, B-1050 Brussels, Belgium
[2] Brown Univ, Sch Med, Div Infect Dis, Providence, RI 02912 USA
[3] Hosp Clin Barcelona, Clin Inst Pneumol & Thorac Surg, E-08036 Barcelona, Spain
[4] Hosp Clin Barcelona, Resp Intens Care Unit, E-08036 Barcelona, Spain
[5] Univ Med Ctr Utrecht, Dept Internal med & Dermatol, Div Acute Internal med & Infect Dis, Utrecht, Netherlands
[6] Brighton & Sussex Med Sch, Brighton, E Sussex, England
[7] Univ Tennessee, Memphis, TN USA
[8] Methodist Le Bonheur Healthcare, Res Dept, Memphis, TN USA