Study of single infections and mixed infections by respiratory syncytial virus in children with acute lower respiratory tract disease.

Objective To investigate the clinical relevance of multiple viral infections in children with acute lower respiratory disease. Methods A total of 1722 children with clinical diagnosis of lower respiratory tract infection(ALRTI)during the period of October 2007 to September 2011 were involved in our study. One nasopharyngeal aspirate specimen was collected from each patient.(RT)PCRs were performed to detect common respiratory tract viruses including respiratory syncytial virus(RSV),rhinovirus(RV),influenza virus type A and B,parainfluenza virus(PIV)type 1-4,adenovirus,enterovirus,human coronavirus,human metapneumonia virus and human bocavirus. Results Totally 206 children had single RSV infection,124 children had dual infections(RSV co-infected with an additional virus)and 40 children had multiple infections along with a RSV infection. Out of the 124 patients,68(54.8%)were co-infected with RV,24 with PIV. There was a statistically significant difference between the dual viral infections group and the RSV-infected group in hospital stay(P0.001).Compared to patients in the single RSV infected group,patients in the multiple viral infection group had significantly more frequency in fever(P=0.017),duration of fever longer(P=0.015),hospital stay also longer(P0.001),and they received more intravenous steroid therapy during hospitalization(P=0.005). There was no significant difference in oxygen therapy,respiratory support and use of bronchodilators. Conclusion Multiple viral infections are linked to more frequency in fever,longer fever days,longer hospital stay,and more frequent use of intravenous steroid therapy during hospitalization. Mixed respiratory virus infection may affect the patient's disease severity and prognosis.