title: The impact of atopic disease on the risk of post-infectious fatigue and irritable bowel syndrome 3 years after Giardia infection. A historic cohort study.
abstract: OBJECTIVE
  To investigate whether atopic disease influences the prevalence of irritable bowel syndrome (IBS) and chronic fatigue (CF) after giardiasis.
  
  
  METHODS
  A questionnaire was sent to all confirmed cases of giardiasis after a Norwegian outbreak, with response rate of 65.3% (817/1252). Controls were randomly selected matched on age and sex, with response rate of 31.4% (1128/3598). Associations were evaluated by use of logistic regression analyses.
  
  
  RESULTS
  In the Giardia exposed group, 47.8% of those with asthma had IBS compared with 45.3% in those without asthma (p = 0.662). For controls, corresponding percentages were 23.9% and 12.2% (p < 0.001). Among those with asthma, the adjusted relative risk (RR) for IBS was 2.03 (95% confidence interval (CI): 1.45, 2.62) for the exposed group compared with controls. In those without asthma, the corresponding RR was 3.80 (95% CI: 3.30, 4.32). In the exposed group, 51.5% of those with asthma had CF compared with 44.9% in those without asthma (p = 0.218). For controls, corresponding percentages were 19.3% and 10.7% (p = 0.004). Among those with asthma, the adjusted RR for CF was 2.73 (95% CI: 1.98, 3.45) for the exposed compared with controls. In those without asthma, the corresponding RR for CF was 4.25 (95% CI: 3.66, 4.85).
  
  
  CONCLUSIONS
  For the exposed, having asthma or allergy did not increase the outcome of IBS or CF. For the control group, having an atopic disease made a substantial risk difference, with significantly more IBS and CF.
authors: Department of Public Health and Primary Health Care, University of Bergen, Norway. gunnhild.hunskar@student.uib.no
authors: Gunnhild S
authors: GS
authors: Hunskar
authors: Nina
authors: N
authors: Langeland
authors: Knut-Arne
authors: KA
authors: Wensaas
authors: Kurt
authors: K
authors: Hanevik
authors: Geir Egil
authors: GE
authors: Eide
authors: Kristine
authors: K
authors: Mørch
authors: Guri
authors: G
authors: Rortveit
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D004196:Disease Outbreaks; D005221:Fatigue / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D005873:Giardiasis / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology*; D007223:Infant; D043183:Irritable Bowel Syndrome / Q000453:epidemiology* / Q000209:etiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D016017:Odds Ratio; D015995:Prevalence; D011795:Surveys and Questionnaires; D055815:Young Adult