Surveillance For Respiratory Syncytial Virus Subtypes A And B In Children With Acute Respiratory Infection

Objective To characterize the prevalence and occurrence of subgroups of human respiratory syncytial virus(RSV) in infants and young children with acute respiratory infections(ARI) in yanbian area.Methods RSVs were identified from nasopharyngeal aspirates and throat swabs collected from infants and children with ARI who visited our hospital during the period of November 2002 to April 2006, by virus isolation in Hep-2 cells and antigen detection by indirect immunofluorescence assay (IFA), RT-PCR was used to differentiate subgroups A and B of RSV from part of the Positive specimens.Results Out of 1005 specimens, 229(22.8%) were RSV positive. The positive rate for RSV identification were 29.9% (215/229) in specimens from the hospitalized patients, which was higher than that from outpatients (4.9%, 14/229). (2) Positive rates for RSV detection were 40.2%, 40.1% in the seasons of 2002-2003, 2004-2005, which wre higher than those in seasons of 2003-2004(17.6%), 2005-2006(20.0%) Subtyping of A and B during the surveillance period showed that 70.6% (66/94) were subgroups A and 29.4% (28/94) were subgroups B. Subgroups A was predominant in 2002-2003, 2003-2004 seasons, whereas subgroups B predominated in 2005-2006 seasons. Almost equal proportions of subgroup A and B appeared in 2004-2005 seasons.Conclusion The data indicate that RSV is an important etiological agent for lower respiratory infections in infants and young children in winter and spring during the survey period. The pattern of RSV circulation waried alternately with higher rate every other year. The predominant subgroup changed between A and B, and co-circulated in equal proportion in some years.