title: Severity of Giardia infection associated with post-infectious fatigue and abdominal symptoms two years after.
abstract: BACKGROUND
  A high rate of post-infectious fatigue and abdominal symptoms two years after a waterborne outbreak of giardiasis in Bergen, Norway in 2004 has previously been reported. The aim of this report was to identify risk factors associated with such manifestations.
  
  
  METHODS
  All laboratory confirmed cases of giardiasis (n = 1262) during the outbreak in Bergen in 2004 received a postal questionnaire two years after. Degree of post-infectious abdominal symptoms and fatigue, as well as previous abdominal problems, was recorded. In the statistical analyses number of treatment courses, treatment refractory infection, delayed education and sick leave were used as indices of protracted and severe Giardia infection. Age, gender, previous abdominal problems and symptoms during infection were also analysed as possible risk factors. Simple and multiple ordinal logistic regression models were used for the analyses.
  
  
  RESULTS
  The response rate was 81% (1017/1262), 64% were women and median age was 31 years (range 3-93), compared to 61% women and 30 years (range 2-93) among all 1262 cases. Factors in multiple regression analysis significantly associated with abdominal symptoms two years after infection were: More than one treatment course, treatment refractory infection, delayed education, bloating and female gender. Abdominal problems prior to Giardia infection were not associated with post-infectious abdominal symptoms. More than one treatment course, delayed education, sick leave more than 2 weeks, and malaise at the time of infection, were significantly associated with fatigue in the multiple regression analysis, as were increasing age and previous abdominal problems.
  
  
  CONCLUSIONS
  Protracted and severe giardiasis seemed to be a risk factor for post-infectious fatigue and abdominal symptoms two years after clearing the Giardia infection.
authors.affiliation: National Centre for Tropical Infectious Diseases, Haukeland University Hospital, Bergen, Norway. mokr@helse-bergen.no
authors.forename: Kristine
authors.initials: K
authors.lastname: Mørch
authors.forename: Kurt
authors.initials: K
authors.lastname: Hanevik
authors.forename: Guri
authors.initials: G
authors.lastname: Rortveit
authors.forename: Knut-Arne
authors.initials: KA
authors.lastname: Wensaas
authors.forename: Geir Egil
authors.initials: GE
authors.lastname: Eide
authors.forename: Trygve
authors.initials: T
authors.lastname: Hausken
authors.forename: Nina
authors.initials: N
authors.lastname: Langeland
mesh_terms: D015746:Abdominal Pain / Q000453:epidemiology / Q000469:parasitology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003248:Constipation / Q000453:epidemiology / Q000469:parasitology; D003967:Diarrhea / Q000453:epidemiology / Q000469:parasitology; D004196:Disease Outbreaks; D005221:Fatigue / Q000453:epidemiology* / Q000469:parasitology; D005260:Female; D005767:Gastrointestinal Diseases / Q000453:epidemiology* / Q000469:parasitology; D005873:Giardiasis / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000453:epidemiology / Q000469:parasitology; D009664:Norway / Q000453:epidemiology; D012307:Risk Factors; D011795:Surveys and Questionnaires; D055815:Young Adult