Borrelia burgdorferi exposure in coyotes: an indicator of B. burgdorferi levels in urban versus rural environments

Laura Shultz,Erik Fausak

doi:10.18849/ve.v7i1.444

Abstract

PICO question Do wild coyotes in the US that are in an urban habitat compared to a rural habitat have a higher prevalence of Borrelia burgdorferi seroconversion?  Clinical bottom line Category of research question Prevalence The number and type of study designs reviewed Two papers, both utilising a cross-sectional study design Strength of evidence Zero Outcomes reported The relevant studies provide very limited to no evidence towards answering this PICO question. In one, while the absolute percentage of Borrelia-antibody-positive canines (including dogs in addition to coyotes) is higher in metropolitan areas, the effect was not found to be statistically significant, possibly due to their small sample sizes. In the second study, prevalence of antibodies against Borrelia was compared between different rural habitats, but no urban coyotes were tested as a comparison and thus the PICO question cannot be evaluated Conclusion There is a knowledge gap concerning the prevalence of Borrelia in coyotes and how it differs between urban and rural environments. Wild coyotes could be used as a sentinel species of Lyme disease activity and to assess potential for domestic pet and human infections, which would inform clinical differential diagnoses as well as testing and vaccination recommendations. More studies are needed before this PICO question can be answered in a confident manner  How to apply this evidence in practice The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources. Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care. 

Highlights

Sera were tested by ELISA for Borrelia burgdorferi antibodies with results being validated via Western blot test and/or indirect fluorescent antibody (IFA) tests at reference laboratories. o Criterion for positive ELISA: spectrophotometrically three standard deviations above the mean optical density of samples from control animals. o Criterion for positive Western blot test: presence of 5/10 most common antigen IgG bands. o Criterion for positive IFA: >1:128 of the equivalent when correlating for interlaboratory variability
Outcome studied: The objective of this study was to determine the seroprevalence of B. burgdorferi in San Diego county as assessed in canines, who can serve as a sentinel for human risk of Lyme disease cases
At the time of this writing, there is a paucity of information concerning how prevalence varies between urban and rural environments and if this can inform clinical decisions of veterinarians; more research is needed in order to determine if wild coyotes have a higher prevalence of B. burgdorferi seroconversion in an urban habitat compared to a rural habitat, and if wild coyotes are a good sentinel species for B. burgdorferi in urban environments

Summary

Conclusion

There is a knowledge gap concerning the prevalence of Borrelia in coyotes and how it differs between urban and rural environments. Rural, and wilderness environments and can serve as a sentinel species to indicate Borrelia disease levels and geographical trends to help inform diagnoses and vaccination recommendations. The evidence While cross-sectional studies provide a high level of evidence for prevalence questions assessing exposure to this pathogen, neither of the two studies evaluated here were directly investigating whether Borrelia burgdorferi levels vary between urban and rural environments in wild coyotes of the United States. With no tested urban coyotes clearly identifiable, this study does not allow us to answer the target PICO question but does explore variation within rural environments at a finer scale (Foley et al, 2005). There were no papers that directly addressed this PICO question, which identifies a gap in knowledge where further research is needed

Summary of the evidence

Limitations:

Methodology

CONFLICT OF INTEREST