Impact of RSV Infection in Transplant and Immunocompromised Population: Incidence and Co-Infections: Retrospective Analysis of a Single Centre.

Respiratory syncytial virus (RSV) represents one of the main respiratory infections found among immunocompromised patients. : The study analyzes the incidence of RSV infection in different populations of immunocompromised patients as organ transplant recipients (lung, other solid organs, hematopoietic stem cells) and oncologic patients (solid organ malignancy and hematological malignancy) compared to a group of non-immunocompromised patients. We also assessed the prevalence of viral, bacterial, and mycotic coinfection. Moreover, we aimed at evaluating the efficacy of ribavirin treatment in terms of mortality reduction. : We conducted a retrospective analysis on a total of 466 transplant patients undergoing bronchoscopy with bronchoalveolar lavage for suspected viral disease or surveillance between 2016 and 2023, compared to 460 controls. : The incidence of RSV was significantly higher in immunocompromised patients, particularly in those with lung and bone marrow transplants. Among RSV+ patients, a higher prevalence of viral (influenza virus), bacterial (, , spp.), and fungal ( spp.) coinfections were observed. The efficacy of ribavirin in reducing mortality did not show significant differences compared to supportive therapy alone. : The results of our exploratory study suggest that immunocompromised patients are particularly vulnerable to RSV infection and coinfections. Our hypothesis-generating data warrant the need for future studies aimed at exploring preventive and therapeutic strategies for RSV infection in these high-risk patient groups.