Characterization of anthrax occurrence in North Dakota: Determinants, management strategies, and economic impacts

The 2005 anthrax outbreak in North Dakota was the largest anthrax epizootic in the records of the state with over 243 animal cases identified by diagnosis. The cases were clustered mainly around the eastern region of the state, specifically in 16 counties. The study had 4 objectives which included: to characterize the outbreak among animals and determine characteristics associated with the disease; to identify risk factors associated with the outbreak in animals; to evaluate the economic impact of anthrax occurrence in cattle; and to review the control strategies currently used in management of anthrax in livestock and their to producers.;Anthrax cases were defined as animals with typical clinical signs and positive results of laboratory culture and/or Polymerase Chain Reaction methods. Data for the study were obtained from the state Veterinary Diagnostic Laboratory records, the state veterinarian's office, and questionnaires mailed to producers in the state. We used a case series design, a case-control design, a theoretical analysis of the economic impact, and a review of anthrax management practices to answer the objectives.;We found that animals affected, clinical signs, and final outcome were consistent with a natural anthrax outbreak. We also identified factors that were significantly different between case and control premises, or factors that significantly predicted anthrax occurrences. These predictors were vaccination status, use of antibiotics during an outbreak, and the period of vaccine administration. The cost of the anthrax outbreak was estimated at USD...