Respiratory Viral Infections in the Pediatric Hematopoietic Stem Cell Transplant Population: Progression to Lower Respiratory Tract Disease.

Background: Respiratory viral infections (RVIs) are important complications in pediatric patients undergoing hematopoietic stem cell transplantation (HSCT); however, risk factors for lower respiratory tract infections (LRTIs) are not well characterized. The aim of this study was to determine risk factors for the progression to LRTIs in pediatric patients with respiratory symptoms who underwent HSCT.

Patients And Methods: This retrospective study included 87 pediatric patients with respiratory symptoms who underwent HSCT. Respiratory viral polymerase chain reaction samples were obtained from all patients. The evaluated data included risk factors to progression to LRTIs, long-term pulmonary complications, transplantation-related mortality, and overall survival.

Results: Viral pathogens were detected in 31 (48.4%) patients with upper respiratory tract infections and 13 (56.5%) patients with LRTIs. There was a statistically significant difference between the groups in engraftment delay and lymphocytopenia. Also it was determined that engraftment delay (odds ratio: 7.46 [95% CI, 1.99 to 27.86]; P = 0.003) and COVID-19 infection had statistically significant effects on overall survival in general (odds ratio: 8.06 [95% CI, 2.63 to 24.64]; P <0.001]).

Conclusion: Not only host and transplant-related factors but also viral agent type were found to be effective in progression to LRTIs. As the available therapy for respiratory viral infections remains limited, the focus should be on the prevention of infection.