Animal-Encounter Fatalities, United States, 1999-2016: Cause of Death and Misreporting

Errors and misreporting on death certificates are common, along with potential inaccuracies in cause-of-death coding. We characterized and compared fatalities by animal-encounter mentions reported as underlying cause of death (UCD) with animal-encounter mentions reported as multiple cause of death (MCD) to determine factors associated with misreporting UCD.

We analyzed fatality data from 1999-2016 from the Centers for Disease Control and Prevention Wide-ranging ONline Data for Epidemiologic Research by UCD and MCD animal-encounter mentions (International Classification of Diseases, 10th Revision codes W53-59, X20-27 and X29, T63.0-63.6, T63.8-63.9, and T78.2-78.4). We examined differences in reporting by age, sex, race, autopsy (yes, no, unknown), allergic reactions, and toxicities.

The number of animal-encounter mentions by UCD was 3638 (202 average per year) and by MCD was 4280 (238 average per year), a difference of 18% (n = 642; 36 average per year) by MCD analysis. The number of nonvenomous animal-encounter mentions increased 20% (from 2138 UCD to 2567 MCD), and the number of venomous animal-encounter mentions increased 14% (from 1500 UCD to 1713 MCD). Decedents aged ≥65 had the highest additional number of animal-encounter mentions among all age groups, primarily encounters with other reptiles (n = 113), other mammals (n = 71), and dogs (n = 42). Of 642 MCD additional animal-encounter mentions, heart disease (n = 211, 33%) and infections (n = 146, 23%) represented more than half of the UCD. Of 553 dog-encounter fatalities, 165 (30%) were among children aged ≤4.

Animal-encounter fatalities, analyzed by UCD alone, may be underreported. An initiating animal injury, complicated by comorbidities and fatality, may obscure the causal chain, resulting in misreporting UCD. Ongoing training for medical certifiers is recommended, highlighting accurate identification of UCD and contributing causes in the causal chain of death.