B53-26 Fatal Acute Respiratory Distress Syndrome Due to Human Bocavirus Infection in a Lung-Transplant Recipient

Introduction Human bocavirus (HBoV), a member of the Parvoviridae family, is a well-recognized cause of respiratory infections in children but is infrequently identified in adults. Solid-organ transplant recipients are at risk for severe viral infections due to long-term immunosuppression; however, HBoV-associated respiratory failure in this population remains rare. Case Presentation A 26-year-old man with pulmonary hypertension, status post bilateral lung transplantation in 2023 on tacrolimus and prednisone, presented with progressive shortness of breath. He had been recently hospitalized for a similar episode, during which a chest CT showed diffuse bilateral ground glass opacities. Bronchoscopy at that time revealed diffuse bronchomalacia and thick mucoid secretions. The respiratory pathogen panel was positive for human bocavirus, while other diagnostic studies, including cryptococcal antigen and HIV testing, were negative. He was treated empirically with ribavirin, cefepime, doxycycline and 40 mg of prednisone for presumed organizing pneumonia. Despite this, his respiratory symptoms persisted. On the current presentation, the patient was tachypneic and in respiratory distress on BiPAP. Physical examination revealed coarse breath sounds bilaterally. He was admitted to the ICU. The following morning, he developed multiple episodes of hemoptysis and acute desaturation necessitating emergent intubation. Arterial blood gas revealed a PaO2/FiO2 ratio of 80.6, consistent with severe ARDS. Bedside bronchoscopy demonstrated friable airways with thick secretions. Comprehensive infectious workup was negative. The patient was managed with lung-protective ventilation, diuresis, prone positioning, and neuromuscular blockade. Despite these measures, he developed a sudden pulseless arrest. Given concern for possible pulmonary embolism, tPA was administered, but no spontaneous circulation was achieved after 30 minutes of CPR. The patient was pronounced deceased. Discussion HBoV infection is rarely associated with severe respiratory illness in adults, but emerging reports suggest it can cause life-threatening pneumonia in immunocompromised patients, including transplant recipients. Its pathogenesis likely involves direct cytopathic injury combined with dysregulated host immune responses. In this case, HBoV was the only identified pathogen despite comprehensive microbiologic testing, supporting its etiologic role. Airway friability and bronchomalacia may have contributed to impaired clearance and secondary alveolar damage. The patent’s immunosuppressed status likely facilitated unchecked viral replication and delayed recovery. Therapeutic options for HBoV infection are limited; ribavirin has been used, though evidence for efficacy is anecdotal. Supportive measures remain the cornerstone of management. Conclusion Human bocavirus should be considered in the differential diagnosis of unexplained viral pneumonia or ARDS in lung-transplant recipients, particularly when standard microbial studies are negative. This abstract is funded by: None