Elimination of Mycobacterium avium subspecies paratuberculosis from dairy farms: fact or fiction?

Abstract

ABSTRACT In this key note paper, we discuss whether elimination of Mycobacterium avium subspecies paratuberculosis (MAP) from dairy farms is a realistic option for modern dairy farms. Longitudinal observational studies have shown that farms may have low apparent prevalence of MAP for long periods of time. This is remarkable as it may be expected that a low prevalence would result in infection fade out from a substantial proportion of the farms. We present data that would indicate that the true MAP prevalence on dairy farms is much higher. Data from tissues collected at slaughter in cows from longitudinally studied herds show an apparent prevalence of infection in culled cows of approximately twenty-five percent. The reasons for this high prevalence are discussed. The impact of this high prevalence for control programs is evaluated using both mathematical, economical and molecular tools. We conclude that elimination of MAP for most dairy farms is more fiction than fact