Clinical Characteristics and Course of Infections by Influenza A and Respiratory Syncytial Virus (RSV) in Hospitalized Adults

There is little evidence on the clinical characteristics and the course of complicated infections with respiratory syncytial virus (RSV) compared to influenza A in adults. Therefore, the present monocenter study aims to compare infections with RSV and influenza A with regard to potential predisposing factors, clinical profile, course and outcome in hospitalized patient. Material and methods the study was performed between Jan 1 th and March 31 this year and included all hospitalized patients with a Polymerase chain-reaction-(PCR) confirmed infection of influenza A and RSV. Patients were characterized by clinical symptoms at the time of diagnosis, laboratory parameters of inflammation and potential predisposing factors like chronical diseases of heart, lung, kidney, metabolism and tumors. Data on the length of hospital stay, origin of infection (nosocomial), rate of pneumonia, antimicrobial use, need of mechanical ventilation and hospital mortality were obtained to evaluate clinical severity and outcome. Results A total of 190 patients with Influenza A and 98 patients with RSV were included. Both patient groups did not differ with regard to anthropometric data and clinical symptoms: it was surprising to see that only 2/3 oft all patients exert symptoms of a respiratory infection. 15.3% of influenza A and 13.3% RSV infections were defined as being nosocomial. Comparing the clinical course and outcome, patients with RSV infections and chronical disease of the lung had an increased rate of mechanical ventilations (odds ratio 10.55 [95% CI 1.18-507.11 p = 0.014). Conclusions The present data clearly show that RSV is a frequent pathogen in hospitalized adults with complicated infections in the winter season. RSV infections seems to be more severe compared to influenza A particular in patients with chronic lung disease, but were as frequent as influenza A of nosocornial origin. In this context, an early diagnosis seems to be helpful for a successful infcctions prevention management under hospital conditions.