Association between risk factors and the occurrence of bovine tuberculosis in cattle and buffalo herds: evidence from a multivariate analysis (2017-2023)-Campania regione.

Abstract

Bovine tuberculosis (bTB), caused by, is one of the most important zoonotic diseases of veterinary and public health concern, with significant economic, productive, and sanitary implications. In the Campania region, characterized by a high density of cattle and buffalo farms and a complex diversity of production systems, understanding the risk factors that influence the persistence and spread of the disease is essential for designing effective control and eradication strategies. This retrospective longitudinal observational cohort study analyzed a seven-year period (2017-2023) with the aim of identifying the main structural, management, and environmental variables associated with the occurrence of bTB outbreaks in cattle and buffalo herds across Campania. Data were integrated from national information systems (SANAN, SIMAN, and BDN) and analyzed using Fisher's exact test, Wilcoxon test, and univariate and multivariate logistic regression models. The covariates considered included herd size, animal movements, previous history of infection, territorial characteristics (farm density, outbreak proximity, presence of pasture), and the presence of other domestic species. In the buffalo cohort (= 892), 13% of farms reported at least one positive case. Independent risk factors identified were previous infection (OR = 3.14; 95% CI: 1.61-5.92), introduction of animals from outside the region (OR = 0.59; 95% CI: 0.19-0.85), and the number of outbreaks within a 2 km radius (OR = 1.19; 95% CI: 1.07-1.33). In the cattle cohort (= 4,467), the prevalence of positivity was 3%. Significant predictors included previous infection (OR = 8.98; 95% CI: 4.18-17.76), presence of pasture within 2 km (OR = 2.65; 95% CI: 1.62-4.19), animal movements (OR = 1.91; 95% CI: 1.11-3.57), and the number of outbreaks within a 2 km buffer (OR = 1.43; 95% CI: 1.28-1.58). The findings highlight the crucial role of herd-level (size and movements), historical (previous infection), and spatial (outbreak proximity, pasture presence) factors in the transmission dynamics of bTB. The integration of epidemiological and spatial analytical approaches provides a comprehensive understanding of the regional risk landscape, offering valuable insights for improving biosecurity, surveillance, and control strategies aimed at reducing the burden of bovine tuberculosis in both cattle and buffalo populations.