Background: Although influenza and parainfluenza viruses commonly cause respiratory tract infections in the community, their incidence and clinical implications in adult lung transplant recipients have received little attention.
Methods: We performed a retrospective cohort study of influenza and parainfluenza viral infections in adult lung transplant recipients at the University of Pittsburgh Medical Center.
Results: Between January 1989 and March 1999, 39 cases (single-lung 25, double-lung 14) of influenza or parainfluenza respiratory viral infection were identified at a mean of 1.7 years (SD+/-1.4) after transplantation. The mean length of admission was 7 days. The cases included 15 patients with influenza (A, 11; B, 4) and 24 with parainfluenza (para1, 7; para2, 2; para3, 15). The median age at diagnosis was 48 years; there were 19 females and 20 males. Symptoms were reported in 30 patients and lasted for a median of 7 days before admission. These included cough (64%), shortness of breath (56%), and temperature elevation (33%). Chest infiltrates were seen in 14 (36%) patients, and 5 (13%) of them required intubation and mechanical ventilation. Viral pneumonia was diagnosed in 10 (5 influenza and 5 parainfluenza) patients, and concurrent bacterial pneumonia occurred in 4 patients. Transbronchial biopsy was performed in 36 patients, of whom 23 (64%) showed some degree of acute allograft rejection.
Conclusion: Influenza and parainfluenza respiratory viral infections are associated with significant morbidity in adult lung transplant recipients. Active vaccination programs and the development of new antiviral agents active against these viruses are important for prevention.