Abstract

Samuel Moges, Saddam Mohammed, Gashaw Getaneh*, Belete Haile, Mebrae Zemene and Hayat Kelifa

ABSTRACT

Paratuberculosis (PTB), or Johne's disease, is chronic infectious granulomatous enteritis of ruminants, caused by Mycobacterium aviumsubspeciesparatuberculosis (MAP). The disease has wide host range that affects domesticated and.wild.ruminants. The bacterium is transmitted by fecal oral route, fomites and vertical transmission. MAP localizes in the mucosa of the small intestine and to its associated lymph nodes and to lesser extent, in the tonsils and suprapharyngeal lymph nodes leading to infiltration the intestinal sub-mucosa. This causes corrugation or thickening of intestinal mucosa, diarrhea and progressive cachexia, which may cause death to the animal. The disease has three forms, silent, subclinical and clinical forms. The disease has strong economic impact especially the subclinical form and public health relevance (possibly transmitted via meat & even pasteurized milk & its products) because of its possible association with Crohn's disease. Necropsy with culture and histopathology on multiple tissues is the gold standard for definitive diagnosis. There are no effective drugs for treatment or effective vaccines for protection against Johne’s disease. Paratuberculosis control program is time consuming and economically relatively costly, hence prevention of a herd or flock from new infection should be the first preventive strategy. Purchasing replacement cattle from disease free herds and other bio-security measures could be helpful to achieve our control strategies.