title: Temporal changes in respiratory adenovirus serotypes circulating in the greater Toronto area, Ontario, during December 2008 to April 2010.
abstract: BACKGROUND
  Certain adenovirus serotypes cause severe infections, especially in children. It is important to monitor temporal changes in serotypes causing clinical disease. The objective of this study was to document circulating respiratory adenovirus serotypes by sequencing adenovirus culture isolates from the Greater Toronto Area, Ontario, during December 2008 to April 2010.
  
  
  METHODS
  Nucleic acid extraction was performed on 90 respiratory tract adenovirus culture isolates. PCR amplification was conducted with primers targeting the adenovirus hexon gene hypervariable region 7. Sanger sequencing and phylogenetic analyses were performed to determine serotype identities.
  
  
  RESULTS
  Among 90 clinical respiratory isolates sequenced, eight different serotypes were identified. Serotype 3 (34, 38%), serotype 2 (30, 30%), and serotype 1 (14, 16%) isolates were most common; serotypes 5, 6, 11, 17 and 21 were also observed. Seventeen (50%) of the 34 HAdV-3 isolates were identified between December 2008 and February 2009, while none were identified from December 2009 to February 2010. Between December 2008 and April 2009, the two most common serotypes were HAdV-3 and HAdV-2, detected in 18 (53%) and 8 (24%) of the 34 cultures isolates, respectively. However, from December 2009 to April 2010, there was an increase in HAdV-2, which became the most prevalent serotype, detected in 10 (50%) of the 20 isolates identified (p = 0.05).
  
  
  CONCLUSIONS
  There was a gradual shift in prevailing adenovirus serotypes during the 17 month study period, from predominantly HAdV-3 to HAdV-2. If an adenovirus vaccine were to be broadly implemented, multiple serotypes should be included.
authors.affiliation: Public Health Ontario Labs, 81 Resources Rd, M9P3T1, Toronto, ON, Canada.
authors.forename: Kaniza Zahra
authors.initials: KZ
authors.lastname: Abbas
authors.forename: Ernesto
authors.initials: E
authors.lastname: Lombos
authors.forename: Venkata R
authors.initials: VR
authors.lastname: Duvvuri
authors.forename: Romy
authors.initials: R
authors.lastname: Olsha
authors.forename: Rachel R
authors.initials: RR
authors.lastname: Higgins
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Gubbay
mesh_terms: D000257:Adenoviridae Infections / Q000453:epidemiology* / Q000821:virology*; D000260:Adenoviruses, Human / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D036022:Capsid Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D009864:Ontario / Q000453:epidemiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012137:Respiratory System / Q000821:virology*; D017422:Sequence Analysis, DNA; D012703:Serotyping; D055815:Young Adult
chemical_list: D036022:Capsid Proteins; D004279:DNA, Viral; C018315:hexon capsid protein, Adenovirus