Salmonella and Campylobacter gastroenteritis increase IBD risk

Last Updated: 2009-08-13 9:00:29 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Gastroenteritis from Salmonella or Campylobacter increases the odds of developing inflammatory bowel disease (IBD), with the risk persisting 15 years or more.

The risk is particularly high for hospitalized patients, according to a report in the August issue of Gastroenterology.

The authors, led by Dr. Henrik Nielsen at Aarhaus University Hospital in Aalborg, Denmark, compared the risks of IBD between 13,148 patients with documented Salmonella or Campylobacter gastroenteritis from 1991 through 2003 and 26,216 age- and gender-matched controls from the same population.

During a mean follow-up of 7.5 years, IBD was diagnosed for the first time in 107 gastroenteritis patients (1.2%) and 73 controls (0.5%), according to the researchers.

The increased risk with exposure was highest during the first year, the authors report.

After adjustments for age, gender, and comorbidity, the hazard ratio for IBD was 2.9 for the whole period and 1.9 if the first year after the gastroenteritis episode was excluded.

Also, hazard ratios for IBD for the whole period were 5.6 for patients hospitalized within 30 days before or after their gastroenteritis, versus 2.1 for patients not hospitalized. Excluding the first year, hazard ratios were 2.4 for hospitalized and 1.8 for non-hospitalized patients.

The increased risk after the gastroenteritis episode persisted throughout the 15-year observation period and was similar for Salmonella and Campylobacter and for a first-time diagnosis of Crohn's disease and ulcerative colitis, the investigators said.

In an editorial, Dr. Lyn Sue Kahng of the University of Illinois at Chicago comments, "It has long been questioned whether specific culprit flora may precipitate the development of IBD."

Perhaps, she says, when infection causes mucosal inflammation and the resulting shift in gut flora, an aberrant genetic background could interfere with appropriate responses and restoration of homeostasis.

"The next several years will be highly interesting as researchers further dissect specific signaling pathways in IBD and the mucosal response to bacteria, as well as the ways in which the gut microbial flora is maintained or perturbed in health and disease," Dr. Kahng concludes.

Gastroenterology 2009;137:415-418,495-501.