Linking Human and Animal Notifiable Zoonotic Disease Data in Washington State

Abstract

Introduction: Although zoonoses are of increasing public and veterinary health concern, and the ‘One Health’ initiative has intensified demand for collaborative zoonoses surveillance, most human and animal disease surveillance systems operate independently. The purpose of this study was to demonstrate the feasibility of integrated approaches to passive zoonoses surveillance in Washington (WA) State, and to explore their potential to improve disease prevention, control, and treatment actions. Methods: We linked and analyzed data on endemically acquired leptospirosis and psittacosis cases in animals and humans reported to the WA State Department of Agriculture and the WA State Department of Health, respectively, from 1993-2016. Results: A significantly higher average number of human and animal leptospirosis reports per month were made from August-December than from January-July. For both diseases, the majority of cases were reported in counties with higher human and pet population densities. Higher pet dog population was associated with increased risk of a human case of leptospirosis in the same county and year, and higher pet bird population and the report of an avian case were associated with increased risk of a human case of psittacosis, although the positive predictive value and sensitivity for an avian case were low. The estimated incidence of psittacosis in pet bird owners and pet shop workers was substantially higher than for all state residents combined. Conclusions: The results of this study may help WA State public and veterinary health officials target disease prevention and control interventions at seasons, counties, and populations at highest risk of infection.