An Update of Epidemiological Trends in Enzootic Bovine Leukosis in Italy and an Analysis of Risk Factors Associated with Infection Persistence.

Abstract

In 2017, the Commission Implementing Decision (European Union [EU]) 2017/1910 officially declared Italy to be enzootic bovine leukosis (EBL)-free. The Commission Delegated Regulation (EU) 2020/689 laid criteria to maintain an official disease-free status. While some infection clusters persist in restricted areas, specific measures are being implemented to eliminate pockets of viral persistence. This updated analysis of current data, concerning epidemiological trends of EBL in Italy from January 2022 to December 2024, aimed to analyze the status of infection clusters in terms of risk factors associated with bovine leukemia virus (BLV) seropositivity to evaluate the effectiveness of the eradication measures. Our findings highlighted an improvement in EBL eradication; however, the Latium region lags behind in terms of disease eradication while the situation in Apulia is being resolved. Campania, which has implemented restrictive and consistent health measures, has the lowest prevalence and incidence rates compared with previous years. Identifying and assessing risk factors that favor EBL persistence in infection clusters is essential as is implementing specific measures to eliminate such clusters, thereby enabling disease eradication and the adoption of targeted prevention strategies.