A COMPARISON AND EVALUATION OF TECHNIQUES FOR DIAGNOSIS OF AVIAN TUBERCULOSIS IN WILDFOWL

To control the epizootic of avian tuberculosis within the collections of captive wildfowl of The Wildfowl and Wetlands Trust an efficacious vaccine and a reliable diagnostic test are required. A number of poten tial diagnostic tests were compared for sensitivity and specificity us ing a flock of 178 feral barnacle geese (Branta leucopsis) at The Wild fowl and Wetland Trust's centre at Slimbridge, Gloucestershire. Evalua tions were made of: serodiagnosis by an enzyme-linked immunosorbent as say (ELISA); agglutination of a suspension of killed Mycobacterium avi um using both whole blood and serum; and haematological analysis. Necr opsy findings confirmed the ELISA to be sensitive and specific, and ca pable of detecting the disease even at an early stage. The agglutinati on tests were quick and easy to perform although a number of false pos itives and negatives did occur. The haematological analysis was found to be less sensitive. ELISA and agglutination tests are now being used to screen the birds in the collections.