Stehman S M
Diagnostic Laboratory, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
Vet Clin North Am Food Anim Pract. 1996 Jul;12(2):441-55. doi: 10.1016/s0749-0720(15)30416-3.
Paratuberculosis in small ruminants is widespread geographically. In some herds and flocks, clinical paratuberculosis, which primarily causes long-term weight loss, can be a significant cause of culling. The effects of subclinical disease are less defined, but they may include decreased milk production in milking sheep and decreased weight gain in deer raised for slaughter. Paratuberculosis also can cause economic losses due to reduced sales of breeding animals from purebred flocks and herds. Diagnosis in goats, deer, and SACs is based primarily on feces or tissue culture and histopathologic examination. Because of the difficulty in growing sheep strains of M. paratuberculosis, diagnosis is based on finding compatible histopathologic lesions with acid-fast organisms. The AGID is a highly specific serologic test for diagnosis of clinical paratuberculosis that correlates with fecal shedding of organisms and degree of severity of lesions; however, it is less sensitive than fecal culture at the herd level for detection of subclinical disease. The CF test detects clinically affected animals but yields poor specificity. The ELISA test is being evaluated for use as a herd screening test in sheep, goats, and SACs. The test seems to be as sensitive as the AGID test but shows a lack of specificity in herds and flocks infected with caseous lymphadenitis. Absorption of sera with Corynebacterium pseudotuberculosis or Mycobacterium phlei may improve specificity, but more studies are needed. Currently, the ELISA test is best used only as a herd or flock screening tool; its use for diagnosis of individual cases requires confirmation with a more specific serologic test or organism detection test such as fecal culture or PCR. Paratuberculosis can be managed and eliminated by combining stringent management with frequent testing and culling or by combining vaccination (where permitted) with management of fecal-oral transmission. Management of fecal-oral transmission is particularly important to prevent exposure of young stock to the infection. Control programs differ with the goals and economics of each farm. The frequency of testing and level of management intervention are determined by each farm's abilities, priorities, and finances.
小反刍动物的副结核病在地理上分布广泛。在一些畜群中，主要导致长期体重减轻的临床型副结核病可能是淘汰动物的重要原因。亚临床疾病的影响尚不明确，但可能包括产奶绵羊产奶量下降以及用于屠宰的鹿体重增加减少。副结核病还会因纯种畜群繁殖动物销售减少而导致经济损失。山羊、鹿和特种动物的诊断主要基于粪便或组织培养以及组织病理学检查。由于副结核分枝杆菌绵羊菌株培养困难，诊断基于发现与抗酸菌相符的组织病理学病变。琼脂凝胶免疫扩散试验（AGID）是诊断临床型副结核病的高度特异性血清学检测方法，与病原体粪便排出及病变严重程度相关；然而，在畜群水平检测亚临床疾病时，其敏感性低于粪便培养。补体结合试验（CF）可检测出临床患病动物，但特异性较差。酶联免疫吸附试验（ELISA）正在评估其作为绵羊、山羊和特种动物畜群筛查试验的用途。该试验似乎与AGID试验一样敏感，但在感染干酪性淋巴结炎的畜群中缺乏特异性。用假结核棒状杆菌或草分枝杆菌吸收血清可能会提高特异性，但还需要更多研究。目前，ELISA试验最好仅用作畜群或禽群筛查工具；其用于个体病例诊断时需要用更特异的血清学检测或病原体检测试验（如粪便培养或聚合酶链反应）进行确认。通过将严格管理与频繁检测和淘汰相结合，或通过将疫苗接种（如允许）与粪-口传播管理相结合，可以控制和消除副结核病。粪-口传播管理对于防止幼畜接触感染尤为重要。控制方案因每个农场的目标和经济状况而异。检测频率和管理干预水平由每个农场的能力、优先事项和财务状况决定。
