Questionnaire for the Diagnosis of Paratuberculosis

Project entitled:

Validation of a Paratuberculosis Questionnaire

Summary

Paratuberculosis is an ailment that is difficult to diagnose prior to its terminal phase. The disease results in sizeable economic losses, even in the absence of clinical signs. A variety of risk factors have been identified on dairy farms. A risk factor questionnaire that is based on known factors is currently available in Quebec to help dairy farmers facing the disease. The goal of this study was to validate the relevance of such a practice and the correlation between a score obtained on the questionnaire and the clinical prevalence in dairy herds whose status—infected or not—is known. About thirty herds having had cases of the disease and an equivalent number of control herds were chosen. A maximum of 30 cows aged 3 years and over were randomly selected from among these herds, and a blood enzyme-linked immunosorbent assay (ELISA) as well as a Mycobacterium avium ssp. paratuberculosis culture of manure were performed. The risk factors questionnaire was then completed with the farmers. Afterwards, the score obtained on the questionnaire was compared to the intra-herd prevalence of the disease. The anticipated potential outcomes were to estimate, using the questionnaire, whether a herd with an unknown status was infected or not and whether the level of infection was serious or mild. This would enable dairy farmers to use a low-cost method to determine whether paratuberculosis was an underlying subclinical problem in their herd.