ABSTRACT
Respiratory infections are leading causes of mortality and morbidity as well as economic loss throughout the world (4). These infections occur at all ages but have the highest mortality rates among the very young, the very old, and the immunocompromised. It has been estimated that the incidence of acute respiratory infections in children of 0^59months of age varies from13 to17 new episodes per 100 child-weeks and the fatality rate is in the range from 3% to 26% in hospitalized children (5). In developing countries, lower respiratory tract infections in children are most important causes of disability and death (6,7). The incidence of respiratory tract infections has increased globally in recent years, in part because of aging of the population (8).
