Fatal Occupational Leptospirosis in a Beef Cattle Farmer: Case Report and Epidemiological Investigation

Leptospirosis is a re-emerging zoonosis responsible for approximately 1 million human infections and 59,000 deaths annually worldwide. In Europe, notification rates have increased by 5% per year since 2010, a trend compounded by climate change. The study was performed to document a fatal occupational case acquired through an under-recognised environmental exposure pathway, and to establish what regional surveillance data can and cannot support regarding its burden and exposure profile. We report a fatal case of occupational leptospirosis in a 56-year-old male beef cattle farmer in Lombardy (Po Valley, Italy) and describe the subsequent epidemiological investigation. Regional surveillance data, veterinary notifications, ECDC data, and an analysis of occupational and climate-related exposure pathways were reviewed. The index case was caused by a strain of serogroup Javanica (microscopic agglutination test titre 1:3,200 against serovar Poi), absent from standard regional animal serological screening panels, probably acquired through contaminated irrigation water. Among 16 confirmed leptospirosis cases in Lombardy over 22 months, 3 (18.8%) died and 1 (6.3%) had permanent disability (severe-outcome rate 25.0%, likely an underestimate given surveillance failures). Twelve of 16 cases (75.0%) had an agricultural-environmental exposure nexus. Leptospirosis risk in irrigated agriculture extends beyond livestock contact to environmental contamination of surface water by wildlife reservoirs. Climate change is expected to expand the disease's European distribution and extend the transmission season. A One Health approach integrating occupational medicine, veterinary surveillance, engineering controls, and climate-adaptive prevention is needed.