SYNOPSISObjective. We identified the risk factors associated with the anthrax outbreak of 2005 in animals in North Dakota.Methods. Medical records of the 2005 anthrax outbreak were obtained from the Veterinary Diagnostic Laboratory at North Dakota State University. Additional data were obtained from the North Dakota state veterinarian's office, and supplemental questionnaires were administered to producers. The data obtained included ecological and environmental factors, animal health factors, and management factors.Results. Anthrax occurred from July 1 to October 12, 2005. The cases were located in eastern North Dakota around the Red River Basin. Ransom, LaMoure, and Barnes counties reported most cases (71%). Species affected included cattle, bison, horses, sheep, elk, deer, pigs, and llamas. The predominant symptom was sudden death (38%) followed by bleeding from orifices (17%). Chi-square analysis indicated significant differences between case and control premises on the following variables: death reported on neighboring pasture, vaccination period, dry conditions, wet conditions, antibiotic use, multiple vaccination, and type of predator (coyote). Factors that significantly (p,0.05) predicted anthrax occurrences on the final logistic regression model were vaccination, use of antibiotics during an outbreak, and period of vaccine administration (before or during the outbreak).Conclusions. The characteristics of the anthrax outbreak regarding time and place of occurrence, animals affected, clinical signs reported, and mortality rate were consistent with previous reports of natural anthrax outbreaks in animals. A number of factors that significantly predicted anthrax occurrence in animals in the 2005 outbreak in North Dakota were identified. This information is important in planning appropriate control and prevention measures for anthrax, including recommending the right vaccination and treatment regimens in managing future anthrax outbreaks.

Outbreaks of anthrax have diverse consequences on society. Establishing the appropriate control strategies is very important and crucial in reducing the socio-economic impact of the disease. Control measures are aimed at breaking the cycle of infection, and their implementation must be adhered to rigorously. The objectives of this paper were: (i) to review the control strategies currently used in management of anthrax in animals and (ii) to describe management strategies used by producers in North Dakota during the 2005 anthrax outbreak in livestock. Anthrax control strategies were divided in to strategies that apply before, during, and after an anthrax outbreak. This paper also highlights the problems or constraints faced by North Dakota producers in controlling anthrax during the outbreak of 2005.

West Nile virus (WNV) outbreak in North Dakota in 2002 included over 569 horse cases, clustered mainly in the eastern and northeastern parts of the state. The pattern of occurrence observed suggested existence of specific environmental and ecological factors that increased the risk for infection and illness in those locations. We developed a predictive model with factors that explained the pattern of WNV occurrence observed. Results indicated that surface elevation, temperature, precipitation, reported WNV-positive birds, reported WNV-positive humans, and reported WNV-positive mosquitoes were important predictors of occurrence in horses. However, case distance from water bodies was not significant in the model. Future predictive models of WNV occurrence in horses should take into account these factors in order to improve accuracy and reliability. Research into other potential determinants such as horse management factors are required to determine more differential risk factors associated with WNV occurrence in horses.

This study estimated economic impacts associated with the West Nile virus (WNV) outbreak in horses for North Dakota in 2002. The 2002 epidemic in the United States was the largest meningoencephalitis epidemic reported in the Western Hemisphere. Over 15,257 horse cases were reported in 43 states with most cases occurring in central United States. North Dakota reported over 569 horse cases, with a mortality rate of 22%. The total costs incurred by the state were approximately US$1.9 million. The costs incurred by horse owners were about US$1.5 million. Of the US$1.5 million, about US$781,203 and US$802,790 were spent on medical costs and losses due to inability to use animals because of the disease, respectively. Medical costs included the cost of vaccinating 152 horses, and the treatment costs for 345 horses which were US$4,803 and US$524,400 respectively. Costs associated with mortality were US$252,000 for the 126 horses which died of WNV. The state government spent US*$400,000 on WNV monitoring, control, and surveillance under the WNV-control program in 2002. Despite these conservative estimates, the data suggest that economic costs attributable to WNV epidemic to horse owners in North Dakota were substantial.

This study examined the roles of the public and private sectors as economic components of anthrax control with direct reference to the 2005 anthrax outbreak in livestock in North Dakota. Anthrax is an endemic disease in North Dakota, which often causes disease outbreaks in livestock, leading to economic losses to the livestock industry. The economic incentives and interests behind public and private control of an anthrax outbreak are investigated. Anthrax management is most effective with the participation of public and private firms. As anthrax is an infectious disease, its control also brings positive economic externalities, which are not accounted for in a producer's decision to protect animals. Therefore, public programs designed to control the disease must be implemented. The government can change producer response to anthrax by setting up policies and incentives that encourage their participation. However, these interventions must encourage compliance and not discourage producers from actively taking part in anthrax management. Producers have economy-based interests and personal reasons for controlling anthrax in their farms. The main reason behind government intervention is to provide assurance to the public who consume livestock products. Another reason is to assist producers and veterinarians, and to achieve biosecurity and biosafety objectives. The contribution of each animal healthcare partner in making anthrax management a success in North Dakota is discussed.