Birgitta Versluijs

100 Results Results During the study period, 310 children with a median age of 7.3 (0.1-22.7) years, received an allogenic HCT. The indication for transplantation was malignant disease in 53%. Non- malignant indications included bone marrow failure syndromes, inborn errors of meta- bolism and primary immune deficiencies. All patients received myelo-ablative conditio- ning; in 76% an unrelated donor was used. RSV-infection was detected in 8 patients (3%) with a median age of 5.2 years (0.2–11 years), Table 1. All infections were community-acquired. Seven patients (88%) contracted RSV before start of conditioning (day -21 to -9 pre-HCT). According to ISI-RSV, 7 patients had a high risk for progression to serious RSV-disease. Only one patient had signs of LRTI at diagnosis. In three patients we saw RSV shedding for 2-7 months. Most patients presented with URTI and did not progress to LRTI. Patient 6, developed dyspnea and hypoxia 3 weeks after HCT, 5 weeks after positive PCR for RSV. Although repeated BAL still showed RSV (CT value 15, compared to 27 pre-HCT), invasive fungal infection was more likely to be the cause of symptoms, based on positive BAL galacto- mannan and findings on chest-HRCT. After initial recovery with antifungal treatment and neutrophil engraftment, the patient died 3 weeks later from respiratory deterioration from a combination of allo-immune lung disease and fungal infection. Patient 7, with initial signs of rhinitis 2 weeks prior to HCT, progressed to LRTI with tachypnea more than 5 weeks later. BAL was still positive for RSV (CT value 18, versus 23 pre-HCT) and negative for other pathogens. At that time, there were early signs of neutrophil engraft- ment. The patient was not hypoxemic and recovered spontaneously within several days. Clinically this was likely to be a mild engraftment syndrome. The patient with RSV ac- quisition post-HCT (patient 8), was also the only child with signs of LRTI at presentation, with tachypnea, cough, hypoxia and fever. She had a normal neutrophil count and only mild lymphopenia. With extra oxygen, stress dose steroids and antibiotics, there was an uneventful recovery within 5 days. Overall, none of the patients received antiviral treatment, none of the patients had severe RSV-related disease and there were no RSV-attributable deaths. 6