title: Occurrence of groups A and B of respiratory syncytial virus over 15 years: associated epidemiologic and clinical characteristics in hospitalized and ambulatory children.
abstract: Over 15 years respiratory syncytial virus (RSV) isolates from 1209 hospitalized and ambulatory children were examined for strain group and in a subset for subgroup to determine the associated epidemiologic and clinical characteristics. Three patterns of yearly outbreaks existed: (1) strong predominance of group A strains (9 years with 83%-100% A strains), (2) relatively equal proportions of group A and B strains (4 years), and (3) strong predominance of group B strains (78%-85%) in 2 years, separated by a decade. The first pattern of highly dominant A strains occurred in cycles of 1 or 2 consecutive years with a single intervening year in which B strains were greater than or equal to 40% of the isolates. Subgroups A1 and A2 predominated, while B2, 3, and 4 occurred almost equally. A greater clinical severity for Group A strains was suggested by children with group A infections requiring intensive care significantly more often (15.4 vs. 8.3%, P = .008). Further, strongly dominant A strain years were associated with higher proportions of RSV admissions requiring intensive care (16.6% vs. 5.5%, P less than .01). Strains of subgroups A2 and B4 were more frequently found in hospitalized patients and A1 in outpatients, and the 2 years with the highest rates of intensive care admissions were those in which subgroup A2 dominated.
authors.affiliation: Department of Pediatrics, University of Rochester School of Medicine and Dentistry, NY 14642.
authors.forename: C B
authors.initials: CB
authors.lastname: Hall
authors.forename: E E
authors.initials: EE
authors.lastname: Walsh
authors.forename: K C
authors.initials: KC
authors.lastname: Schnabel
authors.forename: C E
authors.initials: CE
authors.lastname: Long
authors.forename: K M
authors.initials: KM
authors.lastname: McConnochie
authors.forename: S W
authors.initials: SW
authors.lastname: Hildreth
authors.forename: L J
authors.initials: LJ
authors.lastname: Anderson
mesh_terms: D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007297:Inpatients; D009518:New York / Q000453:epidemiology; D010045:Outpatients; D011446:Prospective Studies; D012136:Respiratory Syncytial Viruses / Q000145:classification*; D010253:Respirovirus Infections / Q000453:epidemiology* / Q000382:microbiology; D012621:Seasons