Clinical and epidemiological characteristics of respiratory virus infections among adults hospitalized during 2004 influenza season

During yearly influenza (FLU) season, FLU viruses are well represented among hospitalized patients as in the community. Also, other respiratory viruses could be represented among adult in-patients. to describe the presence and clinical- epidemiological characteristics of non-FLU respiratory virus infections (respiratory syncytial-RSV, parainfluenza and adenovirus-ADV) among hospitalized adults during FLU season and to compare with FLU-A (IA) or -B (IB) cases. Adult patients hospitalized at Hospital Clínico Universidad Católica between May to July 2004 with a respiratory virus infections confirmed by rapid antigen test or direct immunofluorescence of IA, IB (Flu group) or RSV, parainfluenza (1-2-3) and ADV (non-Flu group) were included. 86 cases were identified: 73.5% FLU (48.2% IA, 25.3% IB) and 26.5% non-FLU (15.7% parainfluenza-2; 8.4% RSV; 1.2% parainfluenza-3; 1.2% ADV). No differences were observed in general characteristics and evolution of patients. In FLU-group were more frequently observed myalgia, cough, hospitalization due to febrile syndrome, higher values of C-reactive protein and band leukocytes count (p < 0.05). During 2004 FLU season a 26.5 % of respiratory viral infection were due to non-FLU viruses among adult hospitalized in our centre. The difficulty to difference FLU vs. non-FLU infections, suggest that it is necessary to include other respiratory virus in the viral etiological diagnosis, even in FLU season.