title: Risk Factors for Severe Adenovirus Infection in Children during an Outbreak in Singapore.
abstract: BACKGROUND
  Human adenoviruses (HAdVs) can cause a variety of human illnesses, with associated temporal and geographic changes in disease incidence. We report the emergence of an outbreak of HAdV infections in Singapore, presumably caused by a change of the predominating type to HAdV-7. We examined the clinical features of children admitted with HAdV infection to 1 institution and the risk factors for severe infection.
  
  
  METHODS
  This is a retrospective case-control study of all HAdV-infected children admitted during weeks 1 to 19 in 2013, as identified from laboratory records. A descriptive retrospective analysis of epidemiology, clinical data and the outcome of these children was also performed. Patients with severe infections were defined as cases, those with non-severe infections as controls, and the 2 groups were compared to find possible independent risk factors.
  
  
  RESULTS
  Eighty-five patients with HAdV infection were studied, including 11 (12.9%) cases and 74 (87.1%) controls. Binary logistic regression showed that cases were more likely to be <2 years old (adjusted OR 10.6, 95% CI, 1.8 to 63.2) and to have significant comorbidities (adjusted OR 19.9, 95% CI, 3.4 to 116.1) compared to controls. The predominant type in 2013 was HAdV-7, which differed from 2011 and 2012, when HAdV-3 was more common. There was a trend towards pneumonia being more common in patients infected with HAdV-7 than in patients infected with other types, although this did not reach statistical significance (OR 2.8, 95% CI, 0.9 to 8.7).
  
  
  CONCLUSIONS
  The emergence of HAdV-7 in a population where other HAdV types had circulated previously may have caused the outbreak in Singapore, and this was associated with more serious infections in children. Young age (<2 years) and significant comorbidities were associated with more severe HAdV infection.
authors: Department of Paediatrics, KK Women's and Children's Hospital, Singapore.
authors: Veena
authors: V
authors: Rajkumar
authors: Cheryl S M
authors: CS
authors: Chiang
authors: Jia Meng
authors: JM
authors: Low
authors: Lin
authors: L
authors: Cui
authors: Raymond T P
authors: RT
authors: Lin
authors: Nancy W S
authors: NW
authors: Tee
authors: Matthias
authors: M
authors: Maiwald
authors: Chia Yin
authors: CY
authors: Chong
authors: Koh Cheng
authors: KC
authors: Thoon
authors: Natalie W H
authors: NW
authors: Tan
mesh_terms: D000257:Adenoviridae Infections / Q000453:epidemiology* / Q000821:virology; D000260:Adenoviruses, Human / Q000235:genetics* / Q000472:pathogenicity; D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D016867:Immunocompromised Host; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012846:Singapore / Q000453:epidemiology