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

Abstract

This systematic review-meta-analysis appraises and summarizes all the available research (128 papers) on the zoonotic potential of Mycobacterium avium ssp. 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 population vs. 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 of M. paratuberculosis in the development or progression of human disease, the evidence at present is not strong enough to inform the potential public health impact of M. paratuberculosis exposure.

Mycobacterium avium ssp . paratuberculosis detection in animals, food, water and other sources or vehicles of human exposure: A scoping review of the existing evidence

“…highlighted that M. paratuberculosis may be isolated from many species, but the contribution of nondomestic ruminant species to human exposure to M. paratuberculosis relative to domestic ruminants has not been closely examined (Mura et al, 2006;Carta et al, 2013). The global evidence reported in this ScR shows that although there are some regional differences, M. paratuberculosis is a global animal health problem, an agri-food problem and possibly a zoonotic public health issue (Waddell et al, 2015).…”

“…paratuberculosis load in many of the animal, food and environmental sources identified in this ScR (Waddell et al, 2015). Future research should address knowledge gaps pertaining to the concentration and prevalence of contamination in various sources that should be addressed to provide the necessary data for an exposure assessment model for humans and evidence-informed decision-making on this potential zoonotic public health issue.…”

“…The year limit of 1984 was selected because it was the year M. paratuberculosis was first isolated in a human (Chiodini et al, 1986). The paratuberculosis and dairy algorithm was implemented from 2005 as a previous SR implemented by this group already included the literature up to 2005 (Waddell et al, 2008), the results of which were transferred into the current review and re-screened using the tools for this ScR. Citations retrieved from all databases were imported into reference management software RefWorks (Copyright 2015, ProQuest LLC) and de-duplicated.…”

“…However, the zoonotic potential of M. paratuberculosis is not fully understood despite 30 years of research. Several studies have identified that M. paratuberculosis is more readily isolated from Crohn's disease patients compared to controls, however the role that M. paratuberculosis may play in Crohn's disease is unknown (Waddell et al, 2015). While there are many knowledge gaps about exposure and conditions under which disease in humans develops; it is critical to better understand the risk of human exposure to M. paratuberculosis from various sources including direct contact with animals, the environment and consumption of potentially contaminated foods and opportunities for risk mitigation interventions.…”

Fecal culture and two fecal-PCR methods for the diagnosis of Mycobacterium avium subsp. paratuberculosis in a seropositive herd

“…The disease produces a significant economic impact on the cattle industry, especially on milk and meat production (Sweeney, 1996;Chacon et al, 2004;García and Shalloo, 2015;McAloon et al, 2016). The agent has also been associated to the chronic human enteritis known as Crohn's disease (Atreya et al, 2014;Hanifian, 2014;Liverani et al, 2014;Waddell et al 2015;.…”