From the Scandinavian Journal of Gastroenterology, 2 July 2012 (e-published before print).
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.
Hunskar GS, Langeland N, Wensaas KA, Hanevik K, Eide GE, Mørch K, Rortveit G.
Department of Public Health and Primary Health Care, University of Bergen, Norway.
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.
RESULT: 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). CONCLUSION: 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.