Fig. 1

Conceptual ranking of evidence used to define a “case” in the paratuberculosis literature. Overwhelming evidence: indisputable diagnostic confirmation of clinical paratuberculosis. Cumulative evidence: range of ante-mortem and post-mortem tests applied and/or repeat testing at separate time points, combined with herd history, leading to greater certainty regarding true infection status. Limited evidence: use of ante-mortem tests such as the milk or serum ELISA and faecal culture, either alone or in combination; parallel interpretation of two or more tests (positive in any of the tests applied); uncertain diagnostic implications of combining information from more than one test