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Cost-effectiveness of using the gamma interferon test in herds with multiple tuberculin reactors - SE3018

Description
The gamma interferon (IFN) test is a laboratory-based blood test developed in Australia in the late 1980s for the diagnosis of tuberculosis in cattle. The test is generally considered more sensitive but less specific than the single intradermal comparative cervical tuberculin (SICCT) test, which is currently used to detect tuberculous cattle in the UK. The IFN test may also detect infected cattle at an earlier stage of the disease than the SICCT test. These positive attributes of the IFN test suggest that it could be used in infected herds to improve the detection of tuberculous cattle and so hasten the elimination of infection from herds.
In this project, decision tree analysis will be used to determine whether the use of the IFN test in multiple tuberculin reactor herds is likely to improve the speed and accuracy of detection at less cost to government and farmers than the current testing protocol. The information obtained by undertaking the project will help MAFF to formulate policy on the use of the IFN test within the tuberculosis control programme in Great Britain and to respond authoritatively to those who advocate use of the IFN test as the solution to TB eradication in Great Britain.
For Objective 04, a feasibility study will be conducted to aid in the design of a larger trial at a later date, in which the SVS will test the effectiveness of combining the SICCT and IFN tests in shortening bovine TB incidents and reducing the recrudescence of bovine TB in herds. In the current study, the IFN test will be conducted in parallel with the SICCT in 5 confirmed incident herds. The study is designed to yield a rough estimate of the costs involved, to gauge farmer and SVS reactions, and to warn of practical issues. Both conventional (PPD) and synthetic antigens will be used in the IFN test, since recent research has shown that using synthetic antigens can reduce the number of reactors slaughtered unnecessarily and possibly can simplify the laboratory test procedure.
Objective
Obj. No. Completed by date Description
01 30.09.2000 To develop decision tree models to determine the cost-effectiveness of using the IFN test in herds with multiple tuberculin reactors in Great Britain compared to the current protocol of using the SICCT test alone.

02 31.01.2001 To use the models and currently available IFN test data to determine whether the use of the IFN test in multiple tuberculin reactor herds is likely to improve the speed and accuracy of detection at less cost to government and farmers than the current testing protocol.

03 31.03.2001 To use the models to re-evaluate the cost-effectiveness of using the IFN test in multiple reactor herds when IFN test data become available from field studies in Great Britain.

04 4 months afterthe resumption ofTB testingin Devonans Staffs, , approx. 31.12.2001 To evaluate the feasibility of using the IFN test in reactor herds, as the basis for a larger field trial.
Project Documents
• Final Report : Final Report for SE3018   (296k)
Time-Scale and Cost
From: 2000

To: 2001

Cost: £124,682
Contractor / Funded Organisations
Veterinary Laboratories Agency
Keywords
Animal Health              
Bovine Tuberculosis              
Control              
Plants and Animals              
Vaccines              
Zoonoses              
Fields of Study
Animal Health