Twenty-five years of suspected rattlesnake encounters in Arizona

Rattlesnake (Crotalus spp., Sistrurus spp.) bites in the southwestern United States are associated with significant morbidity. This study aims to describe 25 years of rattlesnake encounters reported to the Arizona Poison and Drug Information Center to identify vulnerable populations and circumstances where encounters occur to create public education to reduce future bites.

Cases of suspected rattlesnake encounters in Arizona reported to the Arizona Poison and Drug Information Center between 1999 and 2023 were analyzed to identify populations and circumstances associated with encounters.

A total of 3,808 cases were analyzed overall and by age subgroups. Most encounters occurred in men (69.9%), during the evening (16:00-21:59; 49.2%), in summer (41.9%), and close to home (38.2%). Most bites occurred to the lower extremity (51%). Children 0 to 12-years-old have more encounters than those 13-years-old and older in rural zip codes (27.7% versus 14.8%; P = 0.005), during spring (31.8% versus 22.3%; P = 0.0005), and during the evening (64.4% versus 48.1%; P < 0.001).

Rattlesnakes are encountered when rattlesnake and human behavior patterns overlap. Many people spend time outside during evening hours in the summer, and valuable resources like food, water, and shelter can be found near houses where humans spend much of their time. Most age groups have similar encounter circumstances but encounters among children 0 to 12-years-old differ in time of day, season, and urbanization level than encounters of those 13-years-old and older. Limitations of this study include underreporting of encounters, incomplete case details, potential reporting bias, potential snake misidentification, and geographic coverage of the poison center.

Prevention of rattlesnake bites by reducing encounters is the most effective way to reduce suffering and healthcare costs. Future steps include creating and disseminating targeted public health education using the data collected.