title: Influenza outbreaks during World Youth Day 2008 mass gathering.
abstract: Influenza outbreaks during mass gatherings have been rarely described, and detailed virologic assessment is lacking. An influenza outbreak occurred during World Youth Day in Sydney, Australia, July 2008 (WYD2008). We assessed epidemiologic data and respiratory samples collected from attendees who sought treatment for influenza-like illness at emergency clinics in Sydney during this outbreak. Isolated influenza viruses were compared with seasonal influenza viruses from the 2008 influenza season. From 100 infected attendees, numerous strains were identified: oseltamivir-resistant influenza A (H1N1) viruses, oseltamivir-sensitive influenza A (H1N1) viruses, influenza A (H3N2) viruses, and strains from both influenza B lineages (B/Florida/4/2006-like and B/Malaysia/2506/2004-like). Novel viruses were introduced, and pre-WYD2008 seasonal viruses were amplified. Viruses isolated at mass gatherings can have substantial, complex, and unpredictable effects on community influenza activity. Greater flexibility by public health authorities and hospitals is required to appropriately manage and contain these outbreaks.
authors.affiliation: Westmead Hospital, Sydney, New South Wales, Australia. ccblyth@gmail.com
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Blyth
authors.forename: Hong
authors.initials: H
authors.lastname: Foo
authors.forename: Sebastiaan J
authors.initials: SJ
authors.lastname: van Hal
authors.forename: Aeron C
authors.initials: AC
authors.lastname: Hurt
authors.forename: Ian G
authors.initials: IG
authors.lastname: Barr
authors.forename: Kenneth
authors.initials: K
authors.lastname: McPhie
authors.forename: Paul K
authors.initials: PK
authors.lastname: Armstrong
authors.forename: William D
authors.initials: WD
authors.lastname: Rawlinson
authors.forename: Vicky
authors.initials: V
authors.lastname: Sheppeard
authors.forename: Stephen
authors.initials: S
authors.lastname: Conaty
authors.forename: Michael
authors.initials: M
authors.lastname: Staff
authors.forename: Dominic E
authors.initials: DE
authors.lastname: Dwyer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001315:Australia / Q000453:epidemiology; D002648:Child; D004196:Disease Outbreaks; D005260:Female; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D006693:Holidays; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000302:isolation & purification; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics / Q000302:isolation & purification; D009981:Influenza B virus / Q000235:genetics / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D009439:Neuraminidase / Q000235:genetics; D009975:Orthomyxoviridae / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D011634:Public Health; D012137:Respiratory System / Q000821:virology; D055815:Young Adult
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D009439:Neuraminidase
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