Serological cross-sectional study of paratuberculosis in cattle in Austria

From 1915 to 1937, the prevalence of serum antibodies against Mycobacterium avium subspecies paratuberculosis (M. av, ssp.ptbc.) - the causal agent of paratuberculosis (Johne's Disease) - was examined in 11028 Austrian cattle . Samples from the four oldest cattle on 2757 farms were collected accordin g to a specific sampling schedule for this epidemiological study. District, age and breed of animals were included as variables in this study. For ant ibody screening against M avium subspecies paratuberculosis, a modified, co mmercially available ELISA (ALLIED Monitors, Fayette, USA) was employed. A total of 2253 samples that were found to be positive or questionable were s ubjected to further testing with a more specific ELISA (Institute of Microb iology and Infectious Animal Diseases). Results of this study were used for statistical analysis. The average prevalence of antibodies to M avium subs pecies paratuberculosis was 1.99% in Austria. The highest prevalence was se en in 6-year-old cattle (2.84%) and Holstein Frisian cattle (3.51%). Sero-p ostiuve animals were found on 6.96% of farms tested, and the prevalence was highest in Vorarlberg, followed by Salzburg, the Tyrol, Styria and Carinth ia. This study is unique in Europe in the use of an adequate random samplin g plan for an investigation of this magnitude.