Fatal and Nonfatal Snakebite Injuries Reported in the United States

Venomous and nonvenomous snakes are found throughout the United States. Two families of venomous snakes are indigenous to this country: the Viperidae, or pit vipers (rattlesnakes, cottonmouths, and copperheads), and the Elapidae (three species of coral snakes and a sea snake). Bites from captive nonindigenous venomous snakes such as cobras also may present at medical facilities, given the interest in exotic pet ownership in the United States. Even "dry," nonenvenomating snakebites and those from nonvenomous snakes can result in puncture wounds that require medical evaluation. This article presents updated national estimates of snakebite injuries treated in US emergency departments (EDs).

Data on nonfatal snakebite injuries were abstracted from the National Electronic Injury Surveillance System-All Injury Program (2001-2015). Variables included age, sex, body part affected, cause, disposition, and treatment month. The snake species were coded based on narrative comments. Estimates were weighted and analyzed with SAS 9.4. Data on fatal snakebites were obtained from the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiological Research (1999-2017).

From 2001-2015, an estimated 137,800 snakebite injuries were treated in US EDs (crude rate: 3.0 individuals per 100,000 population). The majority of patients were male (70.7%; crude rate 4.4/100,000 population). Arms/hands (46.8%) and legs/feet (46.1%) were the primary body parts injured. The majority of patients were treated and released (67.1%); however, nearly 30% were hospitalized or transferred to another hospital. Two-thirds of the cases involved a nonvenomous or unknown snake (67.7%). Among venomous encounters, 70.3% involved a rattlesnake. For fatal snakebites, an average of 6 deaths per year was reported (range 2-12).

Although rare, nonfatal snakebites in this study resulted in an estimated average of 9192 annual visits to EDs (roughly 1 visit per hour) and an average of 6 fatal snakebites per year. Epidemiologic data on snakebite injuries provide healthcare providers, public health officials, and veterinarians with information on populations at risk for snakebites, species of snakes likely to be encountered, and guidance for prevention efforts.