Mycobacterium avium Paratuberculosis Not Associated With Crohn's Disease

NEW YORK (Reuters Health) Mar 29 - Water or dairy products potentially contaminated with Mycobacterium avium paratuberculosis do not appear to play a role in the etiology of Crohn's disease, according to researchers.

"Mycobacterium avium paratuberculosis (MAP) causes Johne's disease, a chronic granulomatous intestinal condition which affects ruminants," Dr. Ibrahim Abubakar, of the University of East Anglia, Norwich, UK, and colleagues write in the March issue of the American Journal of Epidemiology. "Although the etiology of Crohn's disease is still unclear, similarities between the paucimicrobial form of Johne's disease and Crohn's disease have raised concern that MAP may be a causative agent."

The researchers looked into this possibility in a case-control study, involving 218 patients with Crohn's disease recruited from nine hospitals and 812 control subjects were recruited from the community. The participants completed a short questionnaire for evaluation of proxy measures of potential exposure to MAP.

Results of logistic regression analysis showed no significant association with measures of potential contamination of water sources with MAP, water intake, or water treatment.

Multivariate analysis demonstrated a reduced risk of Crohn's disease with consumption of pasteurized milk, but no effect was observed with other dairy products.

Intake of meat was associated with a significantly increased risk of Crohn's disease, while consumption of fruit was associated with a reduced risk.

"The positive association with meat consumption and negative associations with fruit and pasteurized milk consumption suggest that dietary factors may play a role in the etiology of Crohn's, as was suggested by other recent studies," Dr. Abubakar and colleagues conclude. "There is an urgent need for further, more detailed epidemiologic studies investigating the association between diet and Crohn's disease."

Date Posted: April 2, 2007