Abstract:Objective To investigate the pathogenesis and risk factors of post-infectious bronchiolitis obliterans（PIBO）in children，providing a theoretical basis for early identification and intervention. Methods A total of 150 pediatric patients with pulmonary infections admitted to Nanjing Children'’s Hospital and the Fourth Affiliated Hospital of Nanjing Medical University between January 2016 and December 2023 were enrolled. Participants were stratified into a PIBO group（n=65）and control group（n=85）based on PIBO status. Clinical data including infection history，hospital stay，complications，laboratory indexes，imaging findings，and pulmonary function tests were collected. Logistic regression modeling was employed to identify potential risk factors. Results Compared with the control group，the PIBO group had a higher proportion of adenovirus infection（43.08% vs 21.18%），a longer length of hospital stay［（15.88±9.45）d vs（12.89±5.47）d］，and a higher proportion of mechanical ventilation（36.92% vs 16.47%）. Multivariate logistic regression analysis indicated that adenovirus infection（OR=2.842，95%CI：1.292-6.250，P=0.009）and a history of mechanical ventilation（OR=2.476，95%CI：1.018 - 6.023，P=0.046）were independent risk factors for the occurrence of PIBO.Conclusion Children with pneumonia complicated by adenovirus infection and those with a history of mechanical ventilation have a significantly increased risk of developing PIBO，and enhanced monitoring is required in clinical practice.