Symptomatic parainfluenza virus infections in children undergoing hematopoietic stem cell transplantation.

Parainfluenza virus (PIV) infections cause significant mortality in adults undergoing hematopoietic stem cell transplantation (HSCT). Children are more prone to PIV infections than adults; however, data on the epidemiology of these infections in children undergoing HSCT are limited. This study examined the incidence of symptomatic PIV infections, risk factors for lower respiratory tract infection (LRTI), and the impact on mortality after pediatric HSCT. A total of 1028 children who underwent HSCT between 1995 and 2009 were studied. PIV infections were detected in 46 of the 738 patients tested for respiratory infection (6.2%). PIV infection was the most common symptomatic respiratory viral infection in this population. On multivariate logistic regression analysis, receipt of an allogeneic transplant (P < .0001) and total body irradiation-based conditioning (P < .0001) were associated with increased risk of acquiring symptomatic PIV infection. Of the 46 HSCT patients with PIV infection, 18 (39%) had an LRTI. LRTI was associated with PIV infection in the first 100 days post-HSCT (P = .006), use of steroids (P = .035), and absolute leukocyte count (ALC) <100 cells/μL at the onset of infection (P < .0001). An ALC of <500 cells/μL was associated with prolonged viral shedding (P = .045). Six (13%) HSCT patients died of PIV infection. Mortality was associated with African-American ethnicity (P = .013), LRTI (P = .002), use of steroids (P < .0001), mechanical ventilation (P < .0001), and ALC <100 cells/μL at the onset of infection (P = .01). PIV infection causes significant morbidity and mortality in children undergoing HSCT.