Animal Bite Surveillance in Allegheny County, Pennsylvania, 2023

Background: Animal bites are a common injury and significant public health issue due to potential transmission of rabies, a viral pathogen fatal to humans when untreated. Healthcare providers are legally required to report animal bites involving humans to the Allegheny County Health Department (ACHD), which are investigated by ACHD staff. Previous literature utilized emergency department (ED) data to estimate bite incidence and suggested bite underreporting is common. The objectives of this analysis are to analyze reported bites to ACHD, compare characteristics of reported bites to ED data, and evaluate bite reporting completeness. Methods: Bite reports for Allegheny County residents in 2023 were entered by healthcare providers or ACHD staff to an Oracle database. Separate data from emergency department (ED) visits in Allegheny County in 2023 with ICD-10 discharge codes pertaining to bites were obtained through EpiCenter surveillance system. Both datasets were imported to SAS and Microsoft Excel for analysis. ArcGIS Pro was used to verify reported bites occurred within the county or had county resident involvement. Population estimates were obtained from U.S. Census Bureau. Results: ACHD received 2,157 unique mammal bite reports in 2023. Bites were primarily from dogs (76.2%) or cats (20.4%). Victims were more likely to be female (57.9%) and young adults; 25- to 29-year-olds had the highest bite rate by age group. Of reports with treatment location (49.3%), most victims were treated in urgent care centers (29.4%) or hospitals (17.5%). ED data contained 1,370 bite-related visits. By animal species, victim sex, and victim age, bites treated in EDs were similar to ACHD reported bites, although ED visits for raccoon bites (12) outnumbered raccoon bites reported to ACHD (4). Conclusion: Dogs or cats were responsible for most bites. ED visit data was mostly consistent with county reported bites but suggested underreporting of bites from raccoons, which are a species with elevated risk for rabies in the United States. Some hospitals treated many more bites than they reported to ACHD. Animal bites remain a common injury and public health concern; ACHD should continue investigating bites and stress mandatory reporting of bites from health care providers to decrease underreporting.