Canine and human infection with Borrelia burgdorferi in the New York City metropolitan area

Brian H Herrin,Susan E Little,Monica Papeş,Melissa J Beall,Xiao Feng

doi:10.1186/s13071-018-2774-z

Abstract

BackgroundAutochthonous transmission of Borrelia burgdorferi, the primary agent of Lyme disease in dogs and people in North America, commonly occurs in the northeastern United States, including the New York City metropolitan area, a region with a large human and pet population and broadly diverse demographics and habitats.MethodsWe evaluated results from a specific, C6-based serologic assay performed on 234,633 canine samples to compare evidence of past or current infection with B. burgdorferi (sensu stricto) in dogs to county-wide social and environmental factors, as well as to reported cases of Lyme disease in people.ResultsThe data revealed a wide range of county level percent positive canine test results (1.2–27.3%) and human case reports (0.5–438.7 case reports/100,000 people). Dogs from highly (> 50%) forested areas and counties with lower population density had the highest percent positive test results, at 21.1% and 17.9%, respectively. Canine percent positive tests correlated with population-adjusted human case reports (R2 = 0.48, P < 0.0001), as well as population density, development intensity, temperature, normalized difference vegetation index, and habitat type. Subsequent multiple regression allowed an accurate prediction of infection risk in dogs (R2 = 0.90) but was less accurate at predicting human case reports (R2 = 0.74).ConclusionIn areas where Lyme disease is endemic, canine serology continues to provide insight into risk factors for transmission to both dogs and people although some differences in geographic patterns of canine infection and human disease reports are evident.

Highlights

Autochthonous transmission of Borrelia burgdorferi, the primary agent of Lyme disease in dogs and people in North America, commonly occurs in the northeastern United States, including the New York City metropolitan area, a region with a large human and pet population and broadly diverse demographics and habitats
Percent positive canine tests for B. burgdorferi ranged from a high of 27.3% in Putnam County (PU), New York (NY) to a low of 1.2% in Queens County (QU), NY (Fig. 1)
Populationadjusted case reports of human Lyme disease ranged from a high of 438.71 case reports/105 in Dutchess County (DU), NY to a low of 0.50 case reports/105 in Orange County (OR), NY

Summary

Introduction

Autochthonous transmission of Borrelia burgdorferi, the primary agent of Lyme disease in dogs and people in North America, commonly occurs in the northeastern United States, including the New York City metropolitan area, a region with a large human and pet population and broadly diverse demographics and habitats. Deer are a key reproductive host for adult I. scapularis, and several studies in North America document that, in areas where Lyme disease is endemic, higher whitetailed deer populations, measured by resident deer sightings or car accidents involving deer, are associated with an elevated risk of infection with B. burgdorferi [15, 16]. The dilution effect refers to the presence of a diverse array of vertebrates on which immature ticks feed but that do not serve as competent reservoirs for B. burgdorferi This phenomenon is thought to decrease pathogen prevalence in the tick population and reduce overall risk of infection [17, 18]. Deciduous forests provide leaf cover that prevents ticks from desiccation and are associated with increased risk, while open areas, meadows, and regions with established development generally carry a lower risk of infection [19, 20]

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