Diagnostic value of mammalian, avian and johnin PPD tuberculins in cattle herds infected by Mycobacterium paratuberculosis
Körmendy, B.
Acta Veterinaria Hungarica 36(3-4): 177-183
1988
ISSN/ISBN: 0236-6290 PMID: 3254082 Document Number: 311700
Results obtained onthe diagnostic value of "paratubercullin PPD" serving for the diagnosis of paratuberculosis are reported. Paratuberculin was applied in two different concentrations (0.86 and mg/ml and 0.50 mg/ml tuberculoprotein), in a volume of 0.1 ml, and its effect was compared with that of mammalian and avian tuberculin. The allergens were tested on three groups of animals by the intradermal test. The results were read in post-inoculation hour 72. The first group consisted of 62 cows of a diary herd free from parallergic signs (negative control group). In this group all allergens gave negative results. The second group comprised 10 calves (positive control group) orally infected with cultures of Mycobacterium paratuberculosis twice. Tuberculin tests performed on days 92, 217 and 336 after the first infection indicated that, based upon the number and size of the reactions and the proportion of positive and doubtful reactions, the paratuberculin containing 0.50 mg/ml tuberculoprotein showed the highest sensitivity and specificity in diagnosing the infection. The third group comprised a total of 1247 cattle of four farms, all infected by paratuberculosis (test group). The group contained both diary and beef cattle, kept under loose housing conditions or free range management. In this group the paratuberculin containing 0.86 mg/ml tuberculoprotein and apparently also the avian tuberculin were of superior diganostic value. The results suggest that the paratuberculin containing 0.50 mg/ml tuberculoprotein is the allergen of choice for diagnosing the tuberculoid stage of paratuberculosis. With knowledge of the pathogenesis of paratuberculosis, the parallel use of paratuberculin and avain tuberculin may be a valuable aid to the recognition and differential diagnosis of the early stage of paratuberculosis.