The Israel control program for Johne's disease was initiated in 2003. This voluntary program aims to detect infected herds and provide management solutions for the reduction and prevention of herd infection.

Program design

The ensuing stages are followed: 1. Herd obligation to follow the management program; 2. On farm risk assessment; 3. Whole herd testing (ELISA in serum or milk); 4. Fecal culture from seropositive cows; 5. Herd classification in a scale of 1-8, depends on the clinical and serological prevalence and fecal cultures; 6. A herd safety mark calculated from the risk assessment results; 7. A management program is initiated in order to reduce the risk of infection into and within the herd.

Results

During 2003 and 2004, 88 dairy herds were tested (17,400 cows). In herd seroprevalence mean was 2.7% (min 0%, max 9%). 61% of the herds were found to be infected with paratuberculosis (54.5% had clinical cases in the last 3 years and in 6.5% MAP was isolated from fecal cultures). In 20 % infection could not be confirmed despite a more than 0 and up to 4% seropositivity. 19% didn't show any signs of infection (0% seroprevalence without clinical cases). ROC analysis demonstrated that a seroprevalence cutoff of 4% had 95% positive predictive value for the prediction of true infection of the herd (at least one positive culture or clinical case). The prevalence of true infection was 1.84 higher in herds which numbered more than 80 cows (p=0.02), and 1.5 higher in open herds (which purchased cows in the last 5 years) (p=0.021).

Conclusion

Johne's disease is known in Israel and more than half of the herds are truly infected. Despite that fact, the in herd seroprevalence does not reach high. The solution is adopting proper management practices which lead to drop in clinical and subclinical disease.