title: Epidemiology of the reported severity of cottonmouth (Agkistrodon piscivorus) snakebite.
abstract: OBJECTIVE
  The goal of this study was to analyze trends in the annual rates of reported medical outcomes of cottonmouth (Agkistrodon piscivorus) snakebites in the United States, published in the annual reports of the American Association of Poison Control Centers in the course of 29 years.
  
  
  METHODS
  This was a retrospective analysis of medical outcomes for cottonmouth snakebite victims who developed fatal, major, moderate, minor, or no effects. The annual rates for these medical outcomes were calculated by dividing the annual number of patients in each outcome category by the total annual number of people reported as being bitten by cottonmouths. Negative binomial regression was used to examine trends in annual rates.
  
  
  RESULTS
  From 1985 through 2011, after controlling for the availability of CroFab, the annual incidence rate of cottonmouth snakebites causing no effect decreased significantly by 7.3%/year (incidence rate ratio [IRR] 0.927, 95% confidence interval [CI] 0.885-0.970), the incidence rate of minor outcomes did not change significantly (IRR 0.989, CI 0.974-1.006), the incidence rate of moderate outcomes increased significantly by 2.3%/year (IRR 1.023, CI 1.004-1.042), and the incidence rate of major outcomes did not change significantly (IRR 0.987, CI 0.935-1.041). One fatality was reported in 2011.
  
  
  CONCLUSIONS
  Annual rates of cottonmouth snakebites producing no effects decreased significantly, those producing minor outcomes did not change significantly, those producing moderate outcomes increased significantly, and those producing major outcomes did not change significantly, from 1985 through 2011.
authors.affiliation: From the Department of Emergency Medicine, Section of Medical Toxicology, College of Medicine, the Arizona Emergency Medicine Research Center, College of Medicine, University of Arizona, and Rare Disease Therapeutics, Tucson.
authors.forename: Frank G
authors.initials: FG
authors.lastname: Walter
authors.affiliation: From the Department of Emergency Medicine, Section of Medical Toxicology, College of Medicine, the Arizona Emergency Medicine Research Center, College of Medicine, University of Arizona, and Rare Disease Therapeutics, Tucson.
authors.forename: Uwe
authors.initials: U
authors.lastname: Stolz
authors.affiliation: From the Department of Emergency Medicine, Section of Medical Toxicology, College of Medicine, the Arizona Emergency Medicine Research Center, College of Medicine, University of Arizona, and Rare Disease Therapeutics, Tucson.
authors.forename: Robert N E
authors.initials: RN
authors.lastname: French
authors.affiliation: From the Department of Emergency Medicine, Section of Medical Toxicology, College of Medicine, the Arizona Emergency Medicine Research Center, College of Medicine, University of Arizona, and Rare Disease Therapeutics, Tucson.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Chase
authors.affiliation: From the Department of Emergency Medicine, Section of Medical Toxicology, College of Medicine, the Arizona Emergency Medicine Research Center, College of Medicine, University of Arizona, and Rare Disease Therapeutics, Tucson.
authors.forename: Jude
authors.initials: J
authors.lastname: McNally
authors.affiliation: From the Department of Emergency Medicine, Section of Medical Toxicology, College of Medicine, the Arizona Emergency Medicine Research Center, College of Medicine, University of Arizona, and Rare Disease Therapeutics, Tucson.
authors.forename: Farshad
authors.initials: F
authors.lastname: Shirazi
mesh_terms: D017836:Agkistrodon; D000818:Animals; D006801:Humans; D015994:Incidence; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012909:Snake Bites / Q000453:epidemiology*; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology