Parainfluenza virus infections in children with hematologic malignancies.

Background: Parainfluenza virus (PIV) infections are an important cause of morbidity in children with upper or lower respiratory tract infection (URTI and LRTI, respectively). However, the epidemiology of PIV infections in children with cancer has not been well studied.

Methods: This retrospective study sought to determine the epidemiology of PIV infections and risk factors for progression to an LRTI in 1381 children diagnosed with leukemia or lymphoma, between 2000 and 2009.

Results: PIV infections were diagnosed in 83 (10%) of 820 children tested for respiratory infections. PIV type 3 accounted for 49 (61%) of the PIV infections. Of the 83 infections, 75 (90%) were community acquired. Children less than 2 years of age were more likely to have PIV infection (P = 0.002; odds ratio, 2.69; 95% confidence interval, 1.5-4.8). PIV infections were more common in children with acute lymphoblastic leukemia as compared with other malignancies (P < 0.0001; odds ratio, 4.13; 95% confidence interval, 2.37-7.21). The majority of patients, 66 (80%), had URTI. Children with LRTI were a median age of 27 months as compared with 56 months for children with URTI (P = 0.005). Fever with severe neutropenia was more common in patients with LRTI than with URTI (P = 0.02). LRTI was significantly associated with absolute neutrophil count <500 cells/μL (P = 0.002) and absolute lymphocyte count <100 cells/μL (P = 0.008) at onset of PIV infection. There was no mortality attributed to PIV infections, although 3 children required mechanical ventilation for respiratory failure due to PIV infection.

Conclusions: PIV was the second most common respiratory viral infection in this population after influenza (A and B). Young children were more likely to have PIV infection and LRTI. Severe neutropenia and lymphopenia were associated with LRTI.