title: Rapid spread of the novel respiratory syncytial virus A ON1 genotype, central Italy, 2011 to 2013.
abstract: Respiratory infections positive for human respiratory syncytial virus (RSV) subtype A were characterised in children admitted to hospitals in Rome and Ancona (Italy) over the last three epidemic seasons. Different strains of the novel RSV-A genotype ON1, first identified in Ontario (Canada) in December 2010, were detected for the first time in Italy in the following 2011/12 epidemic season. They bear an insertion of 24 amino acids in the G glycoprotein as well as amino acid changes likely to change antigenicity. By early 2013, ON1 strains had spread so efficiently that they had nearly replaced other RSV-A strains. Notably, the RSV peak in the 2012/13 epidemic season occurred earlier and, compared with the previous two seasons, influenza-like illnesses diagnoses were more frequent in younger children; bronchiolitis cases had a less severe clinical course. Nonetheless, the ON1-associated intensive care unit admission rate was similar, if not greater, than that attributable to other RSV-A strains. Improving RSV surveillance would allow timely understanding of the epidemiological and clinicopathological features of the novel RSV-A genotype.
authors.affiliation: Virology Laboratory, Department of Molecular Medicine, Sapienza University, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Pierangeli
authors.forename: D
authors.initials: D
authors.lastname: Trotta
authors.forename: C
authors.initials: C
authors.lastname: Scagnolari
authors.forename: M L
authors.initials: ML
authors.lastname: Ferreri
authors.forename: A
authors.initials: A
authors.lastname: Nicolai
authors.forename: F
authors.initials: F
authors.lastname: Midulla
authors.forename: K
authors.initials: K
authors.lastname: Marinelli
authors.forename: G
authors.initials: G
authors.lastname: Antonelli
authors.forename: P
authors.initials: P
authors.lastname: Bagnarelli
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D058872:Epidemics; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007558:Italy / Q000453:epidemiology; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000737:chemistry; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology*; D018113:Respiratory Syncytial Virus, Human / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D012141:Respiratory Tract Infections / Q000453:epidemiology; D012621:Seasons; D017422:Sequence Analysis, DNA
chemical_list: D012367:RNA, Viral