The zoonotic potential ofMycobacterium aviumssp.paratuberculosis: a systematic review and meta-analyses of the evidence

Abstract

SUMMARYThis systematic review–meta-analysis appraises and summarizes all the available research (128 papers) on the zoonotic potential ofMycobacterium aviumssp.paratuberculosis.The latter has been debated for a century due to pathogenic and clinical similarities between Johne's disease in ruminants and Crohn's disease (108 studies) in humans and recently for involvement in other human diseases; human immunodeficiency virus (HIV) infection (2), sarcoidosis (3), diabetes mellitus type 1 (T1DM) (7) and type 2 (3), multiple sclerosis (5) and Hashimoto's thyroiditis (2). Meta-analytical results indicated a significant positive association, consistently across different laboratory methods for Crohn's disease [odds ratio (OR) range 4·26–8·44], T1DM (OR range 2·91–9·95) and multiple sclerosis (OR range 6·5–7·99). The latter two and the thyroiditis hypothesis require further investigation to confirm the association. Meta-regression of Crohn's disease studies using DNA detection methods indicated that choice of primers and sampling frame (e.g. general populationvs. hospital-based sample) explained a significant proportion of heterogeneity. Other epidemiological studies demonstrated a lack of association between high-risk occupations and development of Crohn's disease. Due to knowledge gaps in understanding the role ofM. paratuberculosisin the development or progression of human disease, the evidence at present is not strong enough to inform the potential public health impact ofM. paratuberculosisexposure.