Respiratory viral infections among pediatric inpatients and outpatients inTaiwan from 1997 to 1999

The present study examined the association of specific virus infections wit h acute respiratory tract conditions among hospitalized and outpatient chil dren in a subtropical country. A total of 2,295 virus infections were detec ted in 6,986 patients between 1997 and 1999, including infections caused by respiratory syncytial virus (RSV) (1.7%), parainfluenza virus (2.0%), infl uenza B virus (2.6%), adenovirus (4.0%), herpes simplex virus type 1 (4.4%) , influenza A virus (5.5%), and enterovirus (12.7%). There were 61 mixed in fections, and no consistent seasonal variation was found. One or more virus es were detected among 24.8% of hospitalized patients and 35.0% of outpatie nts. The frequencies and profiles of detection of various viruses among in- and outpatients were different. The occurrence of enterovirus infections e xceeded that of other viral infections detected in 1998 and 1999 due to out breaks of enterovirus 71 and coxsackievirus A10. RSV was the most prevalent virus detected among hospitalized children, whereas influenza virus was th e most frequently isolated virus In the outpatient group. Most respiratory viral infections (39.3%) occurred in children between 1 and 3 years old. RS V (P < 0.025) and influenza A virus (P < 0.05) infections were dominant in the male inpatient group. In addition, most pneumonia and bronchiolitis (48 .4%) was caused by RSV among hospitalized children less than 6 months old. Adenovirus was the most common agent associated with pharyngitis and tonsil itis (45.5%). These data expand our understanding of the etiology of acute respiratory tract viral infections among in- and outpatients in a subtropic al country and may contribute to the prevention and control of viral respir atory tract infections.