title: The biennial cycle of respiratory syncytial virus outbreaks in Croatia.
abstract: The paper analyses the epidemic pattern of respiratory syncytial virus (RSV) outbreaks in children in Croatia. Over a period of 11 consecutive winter seasons (1994-2005) 3,435 inpatients from Zagreb County aged from infancy to 10 years who were hospitalised with acute respiratory tract infections were tested for RSV-infection. RSV was identified in nasopharyngeal secretions of patients by virus isolation in cell culture and by detection of viral antigen with monoclonal antibodies. In the Zagreb area, RSV outbreaks were proven to vary in a two-year cycle, which was repeated every 23-25 months. This biennial cycle comprised one larger and one smaller season. Climate factors correlated significantly with the number of RSV cases identified only in the large seasons, which suggests that the biennial cycle is likely to continue regardless of meteorological conditions. Knowledge of this biennial pattern should be useful in predicting the onset of RSV outbreaks in Croatia, and would facilitate planning for the prevention and control of RSV infections in the region.
authors.affiliation: Department of Virology, Croatian National Institute of Public Health, Rockefellerova 12, 10000 Zagreb, Croatia. gordana.galinovic@hzjz.hr
authors.forename: Gordana
authors.initials: G
authors.lastname: Mlinaric-Galinovic
authors.forename: Robert C
authors.initials: RC
authors.lastname: Welliver
authors.forename: Tatjana
authors.initials: T
authors.lastname: Vilibic-Cavlek
authors.forename: Suncanica
authors.initials: S
authors.lastname: Ljubin-Sternak
authors.forename: Vladimir
authors.initials: V
authors.lastname: Drazenovic
authors.forename: Ivana
authors.initials: I
authors.lastname: Galinovic
authors.forename: Vlatka
authors.initials: V
authors.lastname: Tomic
mesh_terms: D000956:Antigens, Viral / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D017523:Croatia / Q000453:epidemiology; D004196:Disease Outbreaks; D006801:Humans; D007223:Infant; D009305:Nasopharynx / Q000821:virology; D018357:Respiratory Syncytial Virus Infections / Q000517:prevention & control*; D018113:Respiratory Syncytial Virus, Human / Q000276:immunology / Q000302:isolation & purification*; D012621:Seasons; D014505:Urban Population
chemical_list: D000956:Antigens, Viral