UK paediatric oncology pneumonia surveillance study.

<bold>Background: </bold>Pneumocystis jirovecii pneumonia (PJP) is a serious infective complication of immunosuppressive therapy. There are insufficient data concerning the incidence or mortality rate in children undergoing treatment for malignancies and how these may be influenced by prophylaxis.<bold>Objective: </bold>Prospective collection of clinical information for all suspected and proven cases of PJP in children with cancer in the UK and Ireland.<bold>Design: </bold>A surveillance survey was undertaken using a key contact at each paediatric oncology Principle Treatment Centre (PTC).<bold>Main Outcome Measures: </bold>To describe the mortality, outcomes and use of prophylaxis in this at-risk group.<bold>Results: </bold>The study confirms that PJP is rare, with only 32 cases detected in the UK over a 2-year period reported from all 20 PTCs. No deaths were directly attributed to PJP, in contrast to previously reported high mortality rates. Breakthrough infection may occur despite prescription of ostensibly adequate prophylaxis with co-trimoxazole; 11 such cases were identified. Six infections occurred in patients for whom prophylaxis was not thought to be indicated. Two infections occurred in patients for whom prophylaxis was specifically omitted due to concerns about potential bone marrow suppression or delayed engraftment.<bold>Conclusion: </bold>PJP in children treated for malignant disease is rare. Breakthrough infection despite prophylaxis with co-trimoxazole may represent pathogen resistance or non-compliance. Further consideration of the use of PJP prophylaxis during acute myeloid leukaemia and non-Hodgkin's lymphoma treatment is warranted, alongside appraisal of the clinical implications of the possible marrow suppressive effects of co-trimoxazole and its interactions with methotrexate. [ABSTRACT FROM AUTHOR]