SN/T 1084-2010Quarantine protocol for paratuberculosis of bovine (English PDF)

3.1 General

Paratuberculosis (Paratuberculosis, Johne'sdisease) is a chronic enteritis by ruminants caused by Mycobacterium paratuberculosis.

According to epidemiological, clinical symptoms and pathological changes of the disease, we can make a preliminary diagnosis, but the diagnosis through laboratory diagnosis.

3.2 Epidemiology

Mycobacterium paratuberculosis infection mainly cattle, especially in young cattle more susceptible to disease. In addition to cattle, the sheep, goats, camels, pigs, horses, donkeys, deer and other animals can also be infected. But the long incubation period of up to six months to 12 months or even longer. Sometimes young cattle infected until 2 years old to 5 years old Before clinical signs of any age cattle after 1 year to 2 years of the disease can occur, especially when the cattle pregnancy, childbirth or lactation prone Now symptoms. Cows and latent infected cattle is the source of infection, they can emit large amounts of pathogenic bacteria through breast milk, feces and urine. The disease often has to distribute or Party epidemic, mainly through the digestive tract infection, but also through the uterus and infect the fetus. Popular features of the disease is slow development, the incidence rate is not high, dead Rate, mortality rate of infection of cattle up to 2% to 10%, even up to 25%.

3.3 Clinical symptoms

No obvious symptoms early stages, the symptoms became clear later, beginning with intermittent diarrhea, then gradually severe and frequent, severe, such as feces Water samples, jet-like discharge or gruel-like, containing protein clots, bubbles and large amounts of mucus, occasionally bloodshot. Early spirit, appetite, lactation no significant change Change, after loss of appetite, poor spirit, lactation reduced or stopped. Huanxu gradual weight loss, tired, often lying. Coarse hair disorder, jaw and Wattle edema. But the temperature often change. Continue with diarrhea, the emergence of progressive weight loss, until death.

3.4 Pathological changes

Early lesions in the small intestine and mesenteric lymph duct, with the course of further development, in the ileum, jejunum, posterior segment of the small intestine, cecum and colon, and mesenteric lymph nodes appear visible lesions. Paratuberculosis is not only based on the observation of the surface of the bowel wall thickening and make diagnosis Off, especially on the terminal ileum mucosa mucosal layer, should be pathological thickening and wrinkling of pathological changes, the intestinal wall to get a bright place, see scattered when plaque is infected early lesions. Will make further sample holder (10% formalin) after histological examination of the sample sections were hematoxylin Purple - eosin and Ziehl - Nissl staining, pathology diagnosis of lesions, including infiltration of the lamina propria, Peyer's patches and mesenteric lymph node cortex Large pale infected skin-like cells and giant multinucleated Langerhans cell infiltration, successful cluster or a single acid-fast staining bacteria present in both cells.