Unanswered questions about the transmission of Mycobacterium avium subspecies paratuberculosis

摘要

In ruminants, infection with Mycobacterium avium subspecies paratuberculosis (MAP) is the cause of Johne's Disease, a chronic enteritis that leads to weight loss, intractable diarrhoea, emaciation and death. Johne's Disease is responsible for significant economic losses in ruminant livestock industries worldwide (Hutchinson, 1996). Johne's disease is also coming to prominence for its possible involvement in Crohn's disease in humans. Continued access to international markets as well as the cost to production have been the motives behind national control and eradication programs (Kennedy & Benedictus, 2001).