University of Wisconsin–Madison

Control Programs Work!

R. Scarpelli together with seven Italian colleagues reported on the success of the Voluntary National Control Plan and Guidelines developed by the Italian Ministry of Health in 2013 at controlling paratuberculosis in Italian dairy herds of varying sizes.

Their publication appears in the June 2023 issue of Preventive Veterinary Medicine.

This graphic from their publication shows a steady rise in the number of ELISA negative herds (green bars), and a concomitant decrease in the number of herds with a low percentage of ELISA-positive animals (yellow bars) and number of herds with a higher percentage of ELISA-positive cows (red bars) over the time period of the study, 2017 to 2020. Interestingly, one farm that decided not to follow the proposed control program, but accepted to be sampled every year, showed an increasing rate of ELISA-positive cows (from 5.2% in 2017 to 7.6% in 2020).


Paratuberculosis is considered one of the most economically devastating infectious diseases of domestic livestock, and the most effective control strategy is a combination of ‘test-and-cull’ and on-farm biosecurity measures. In Italy, a Voluntary National Control Plan (VNCP) and guidelines have been introduced to reduce the impact of the disease, and farmers can voluntarily enroll in the control plan. The main aims of this study were: i) the description of the trend over a 4-year period on total, within-herd (WH) and between herd (BH) apparent seroprevalences observed in 64 dairy herds members of a mutual company located in Italy after the introduction of a proposed “Customized Control Plan” (CCP); ii) the evaluation of its effectiveness in terms of percentage of participating farms that decided to join the VNCP. Analyses on serum samples were performed with Enzyme-Linked ImmunoSorbent Assay (ELISA) method and revealed a general decrease in both total, WH and BH apparent seroprevalence. Total average apparent seroprevalence decreased from 2.39% in 2017 to 1% in 2020. Negative herds rose from 51.9% in 2017 to 71.1% in 2020, while farms with WH apparent seroprevalence >5% decreased from 17.3% in 2017 to 4.4% in 2020. BH apparent seroprevalence decreased from 51.2% in 2017 to 29.2% in 2020. Among the 52 out of 64 herds that accepted to continue the proposed CCP after the first year, 41 (78.8%) joined in 2020 the VNCP, that assessed the health ranking of the herds. The results provide evidence that a control plan based on a farm-specific strategy and a subsidized testing process can effectively reduce the impact of paratuberculosis in dairy herds, especially in convincing farmers to continue in paratuberculosis control by joining the VNCP, including them in a national context and increasing their awareness of the disease.


This study adds to the body of literature showing that paratuberculosis (Johne’s disease) in dairy cattle herds can be controlled using a cost-effective diagnostic test (ELISA) combined with herd management changes.