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The objective of this study was to evaluate risks related to introduction of Chronic Wasting Disease (CWD) to farmed cervid herds in Minnesota (MN), Pennsylvania (PA), and Wisconsin (WI). This was the first study to evaluate risk factors related to multiple pathways of CWD transmission to farmed cervid herds. Participating herds in this case-control study included 22 case and 49 control herds identified through participation in the respective mandatory State CWD herd program. Data was voluntarily collected from white-tailed deer (WTD) study herds using a questionnaire and state animal health agency databases. Univariable analyses identified associations between CWD-positive herds and variables representing different transmission pathways, including direct contact with infected farmed cervids (imported from a herd that later tested positive for CWD) odds ratio (OR):7.16, 95 % confidence intervals (CI):1.64-31.21 and indirect contact with infected wild cervids (access of domestic cats to pens or feed storage area) OR:4.07, 95 % CI:1.35-12.26, observed evidence of mammalian scavengers inside or outside of fenceline in the previous 12 months OR:6.55, 95 % CI:1.37-31.32, ≤ 5 km distance to nearest detected CWD-positive wild cervid OR:3.08, 95 % CI:1.01-9.39, forested area crosses the perimeter fenceline OR:3.54, 95 % CI:1.13-11.11, ≤ 0.3 m distance of water source to fenceline OR:4.71, 95 % CI:1.60-13.83, and water source shared with wild cervids (running or standing water) OR:4.17, 95 % CI:1.34-12.92. Three variables from univariable analyses that represented different biological transmission pathways were placed in a Firth's penalized maximum likelihood multivariable logistic regression to evaluate associations between transmission pathway and CWD herd infection status. For the issue of low sample size and overfitting, 95 % CIs for estimated coefficients for the three variables were computed via bootstrapping of 10,000 independent bootstrap samples. The three biological variables were significantly associated with herd CWD infection status: imported cervids from a herd that later tested positive for CWD (OR:5.63; 95 % CI:1.1-28.2), ≤ 0.3 m distance of cervid water source to perimeter fenceline (OR:4.83; 95 % CI:1.5-16.1), and ≤ 5 km distance to nearest detected CWD-positive wild cervid (OR:4.10; 95 % CI:1.1-15.2). The risk factors associated with CWD herd status identified in this study indicated the importance of transmission through direct contact pathways with infected cervid herds (introduction of cervids from herds later identified as CWD-infected) and indirect contact pathways with infected wild cervids that could be related to other animals through the perimeter fence. Further studies are needed to confirm and clarify understanding of indirect pathways to allow development of improved biosecurity practices to prevent CWD introduction to cervid herds., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Disease spread in populations is a consequence of the interaction between host, pathogen, and environment, i.e. the epidemiological triad. Yet the influences of each triad component may vary dramatically for different settings. Comparison of environmental, demographic, socio-economic, and historical backgrounds may support tailoring site-specific control measures. Because of the long-term survival of Bacillus anthracis, Anthrax is a suitable example for studying the influence of triad components in different endemic settings. We compared the spatiotemporal patterns of historic animal Anthrax records in two endemic areas, located at northern latitudes in the western and eastern hemispheres. Our goal was to compare the spatiotemporal patterns in Anthrax progression, intensity, direction, and recurrence (disease hot spots), in relation to epidemiological factors and potential trigger events. Reported animal cases in Minnesota, USA (n = 289 cases between 1912 and 2014) and Kazakhstan (n = 3,997 cases between 1933 and 2014) were analyzed using the spatiotemporal directionality test and the spatial scan statistic. Over the last century Anthrax occurrence in Minnesota was sporadic whereas Kazakhstan experienced a long-term epidemic. Nevertheless, the seasonality was comparable between sites, with a peak in August. Declining number of cases at both sites was attributed to vaccination and control measures. The spatiotemporal directionality test detected a relative northeastern directionality in disease spread for long-term trends in Minnesota, whereas a southwestern directionality was observed in Kazakhstan. In terms of recurrence, the maximum timespans between cases at the same location were 55 and 60 years for Minnesota and Kazakhstan, respectively. Disease hotspots were recognized in both settings, with spatially overlapping clusters years apart. Distribution of the spatiotemporal cluster radii between study sites supported suggestion of site-specific control zones. Spatiotemporal patterns of Anthrax occurrence in both endemic regions were attributed to multiple potential trigger events including major river floods, changes in land use, agriculture, and susceptible livestock populations. Results here help to understand the long-term epidemiological dynamics of Anthrax while providing suggestions to the design and implementation of prevention and control programs, in endemic settings., Competing Interests: The authors have declared that no competing interests exist.

Bovine tuberculosis (bTB) was discovered in a Minnesota cow through routine slaughter surveillance in 2005 and the resulting epidemiological investigation led to the discovery of infection in both cattle and white-tailed deer in the state. From 2005 through 2009, a total of 12 beef cattle herds and 27 free-ranging white-tailed deer (Odocoileus virginianus) were found infected in a small geographic region of northwestern Minnesota. Genotyping of isolates determined both cattle and deer shared the same strain of bTB, and it was similar to types found in cattle in the southwestern United States and Mexico. Whole genomic sequencing confirmed the introduction of this infection into Minnesota was recent, with little genetic divergence. Aggressive surveillance and management efforts in both cattle and deer continued from 2010-2012; no additional infections were discovered. Over 10,000 deer were tested and 705 whole herd cattle tests performed in the investigation of this outbreak.