Can Mycobacterium avium subspecies Paratuberculosis be Transmitted from Cattle to Deer and Rabbits, and Vice Versa?

Abstract

Mycobacterium avium subspecies paratuberculosis (MAP), the causal agent of Johne's disease (JD), infects both wild and domestic ruminants, especially dairy cows. In cattle, the usual route of infection is fecal-oral, with young cattle becoming infected by exposure to manure from infected adult cattle or their environment. The disease manifests in adult cows and results in economic losses. Clinical paratuberculosis has been diagnosed in a number of free-ranging wild ruminant species, especially in North America and Europe, such as Rocky Mountain bighorn sheep, red deer in the western Alps, key deer, and tule elk. In both cattle and wild ruminants, the gastrointestinal tract is the primary site of infection, predominantly the small intestine. In the United States, infected cattle herds have been considered to be an infection source for wild ruminants. In Scotland, MAP was found in rabbits (Oryctolagus cuniculus) that shared the same pasture infected by cattle, and a significant association was found between the presence of MAP in rabbits and cattle farms with JD. Despite the obvious link between JD in wild ruminants or rabbits and domestic ruminants, especially dairy cows, no study has evaluated the possible risk factors associated with cross infection between wildlife and domestic ruminants. The objectives of this study were to assess risk of transmission of MAP among dairy cattle, deer and rabbits, and to estimate prevalence of MAP among deer and rabbits surrounding infected and uninfected Minnesota dairy farms using fecal culture.