Animal Bite and Rabies Surveillance in Allegheny County, Pennsylvania from 2013 to 2020: Trends and lessons learned

Background: Animal bites are a significant public health issue because of the potential for tissue injuries and infections, including rabies. Rabies is a viral infection that is fatal once symptoms begin, but the onset of symptoms can be prevented through post-exposure prophylaxis (PEP), the administration of rabies immune globulin and a series of vaccines after exposure. In Allegheny County, PA, healthcare providers and first responders must report all animal bites to the Allegheny County Health Department. ACHD staff then investigate bite reports and advise victims regarding the appropriateness of rabies PEP. Methods: Bite report data from 2020 were pulled from an Oracle database and analyzed using SAS v. 9.4 and Microsoft Excel. Data visualizations were produced in Excel. Data from 2013 through 2020 were used to analyze trends in bite reports over the eight-year timeframe. Results: There were 2,252 animal bites reported in Allegheny County in 2020. Three-fourths (74.8%) of the reported bites were inflicted by dogs and about one fifth (19.2%) by cats. The most common wild animal exposures were from bats (0.9%) and raccoons (0.5%). Generally, bites to females were reported at a higher rate than bites to males, except for bites reported for children 80 years. Fifty-five bite victims completed rabies PEP in 2020; one victim was exposed to a rabid animal. Forty-five percent of bite victims who completed rabies PEP in 2020 did so unnecessarily. No dog or human rabies cases were identified in the county in 2020. The number of reported animal bites has increased by 27% from 2013 to 2020. Conclusions: The number of reported animal bites in 2020 was higher than for previous years, despite the onset of the COVID-19 pandemic. Domestic animals were responsible for most of the reported bites in 2020. Case investigations of animal bites should be continued to prevent human rabies cases, and ACHD and healthcare providers should follow evidence-based guidelines when recommending treatment and prophylaxis regimens for animal bites, particularly rabies PEP. Describing and analyzing trends regarding animal bites is an important public health activity that can inform future education and prevention efforts