[1] Catalan Transplant Org, Dept Biovigilance, Barcelona, Spain
[2] RCCS Azienda Osped Univ Bologna, Microbiol Unit, Bologna, Italy
[3] Inst Super Sanita, Natl Transplant Ctr, Rome, Italy
[4] WHO, Geneva, Switzerland
[5] Univ Washington, Sch Med, Dept Orthopaed & Sports Med, Seattle, WA USA