¹Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden

²Royal Free and University College Medical School, London, UK

³Newcastle General Hospital, Newcastle upon Tyne, UK

⁴Glasgow Royal Infirmary, Glasgow, UK

⁵Hopital Santa Creu i Sant Pau, Barcelona, Spain

⁶New Children's Hospital, Sydney, Australia

⁷Rikshospitalet, Oslo, Norway

⁸Sahlgren's Hospital, Gothenburg, Sweden

⁹Hopital de la Princesa, Madrid, Spain

¹⁰University Hospital, Utrecht, The Netherlands

¹¹Uppsala University Hospital, Uppsala, Sweden

¹²Nottingham City Hospital, Nottingham, UK

¹³Alfred Hospital, Melbourne, Australia

¹⁴Hopital Henri Mondor, Creteil, France

Correspondence to: Dr P Ljungman, Dept of Hematology, Huddinge University Hospital, SE-14186 Stockholm, Sweden

Community-acquired respiratory virus infections are a cause of mortality after stem cell transplantation (SCT). A prospective study was performed at 37 centers to determine their frequency and importance. Additional cases were also collected to allow the analysis of risk factors for severe infection. Forty episodes were collected in the prospective study and 53 additional episodes through subsequent case collection. The frequency of documented respiratory virus infections was 3.5% among 819 allogeneic and 0.4% among 1154 autologous SCT patients transplanted during the study period. The frequency of lower respiratory tract infections (LRTI) was 2.1% among allogeneic and 0.2% among autologous SCT patients. The mortality within 28 days from diagnosis of a respiratory viral infection was 1.1% among allogeneic SCT while no autologous SCT patient died. The deaths of five patients (0.6%) were directly attributed to a respiratory virus infection (three RSV; two influenza A). On multivariate analysis, lymphocytopenia increased the risk for LRTI (P = 0.008). Lymphocytopenia was also a significant risk factor for LRTI in patients with RSV infections. The overall mortality in RSV infection was 30.4% and the direct RSV-associated mortality was 17.4%. For influenza A virus infection, the corresponding percentages were 23.0% and 15.3%. This prospective study supports the fact that community-acquired respiratory virus infections cause transplant-related mortality after SCT. Bone Marrow Transplantation (2001) 28, 479-484.

RSV infection; influenza; allogeneic; autologous; SCT