ABSTRACT
infection of the lower respiratory tract causes significant morbidity at Assiut University Hospitals in Assiut, Egypt among children and adults. Respiratory viruses play an important role in lower respiratory tract infection affecting individuals of all age groups. To determine the contribution of viruses to lower respiratory tract infection in patients presented or admitted at Assiut University Hospitals, with typing, subtyping, and phylogenetic analysis of the detected viruses. A two-year study was conducted from 2007 to 2009 at the National Influenza Centre [Robert Koch Institute, Berlin, Germany]. Respiratory samples obtained from 520 patients suffered from lower respiratory tract infection were collected. Detection and characterization of the causative viruses was performed using both the conventional methods of viral isolation and molecular methods of real-time polymerase chain reaction and phylogenetic analysis. Seventy nine positive cases were detected with real-time polymerase chain reaction [representing a ratio of 15.2% of the total number of cases] for one or more of the main respiratory viruses [influenza viruses, respiratory syncytial viruses, adenoviruses, and human metapneumoviruses]. Twenty two were children [accounting for 46% of the total number of children included in the study] and 47 were adults [accounting for 10.4% of the adult group]. Viruses are the main cause of lower respiratory tract infection in children and can cause lower respiratory infection in adults hospitalized or presented at Assiut University Hospitals, Egypt, Characterization of the detected viruses revealed that, they were similar to those reported from other parts of the world during the same period. This proves worldwide spread of these viruses during winter-spring seasons