Community respiratory viruses: organ transplant recipients

Respiratory infections are common after solid organ transplantation, but the significance of community respiratory viral infections in this patient population has not been determined. Review of the literature indicates that infection of organ transplant recipients by community respiratory viruses can result in significant morbidity with some associated mortality. These viruses include respiratory syncytial virus (RSV), parainfluenza virus (PIV), influenza virus, and adenovirus. As in normal hosts, infection of organ transplant recipients by these viruses can result in limited upper respiratory tract symptoms, such as rhinorrhea, cough, and fever. Immunocompromised patients can also have lower respiratory tract infection, resulting in bronchiolitis, pneumonitis, respiratory failure, and death. The highest incidence of infection with these viruses is reported in lung transplant recipients, with an incidence up to 21%. In addition to the effects of the usual immunosuppressant regimen, lung transplant recipients have altered lung immunity due to impaired ciliary clearance, poor cough reflex, and abnormal lymphatic drainage, predisposing these patients to lower respiratory tract infections. Of additional importance to organ transplant recipients is the correlation of organ rejection to recent viral infections with these agents. Influenza A and B, PIV, and adenovirus have been reported to be associated with acute rejection in renal transplant recipients. Diagnosis of these infections is often made by positive respiratory cultures, often with a delay between symptom onset and diagnosis. Clinical trials of antiviral agents in this patient population have not been carried out, and treatment has often been limited to severe, life-threatening cases.