Systematic review and meta-analysis of tick-borne disease risk factors in residential yards, neighborhoods, and beyond

BMC Infect Dis. 2019 Oct 17;19(1):861. doi: 10.1186/s12879-019-4484-3.


Background: Exposure to blacklegged ticks Ixodes scapularis that transmit pathogens is thought to occur peri-domestically. However, the locations where people most frequently encounter infected ticks are not well characterized, leading to mixed messages from public health officials about where risk is highest.

Methods: We conducted a systematic review and meta-analysis on spatial risk factors for tick-borne disease and tick bites in eastern North America. We examined three scales: the residential yard, the neighborhood surrounding (but not including) the yard, and outside the neighborhood. Nineteen eligible studies represented 2741 cases of tick-borne illness and 1447 tick bites. Using random effects models, we derived pooled odds ratio (OR) estimates.

Results: The meta-analysis revealed significant disease risk factors at the scale of the yard (OR 2.60 95% CI 1.96 - 3.46), the neighborhood (OR 4.08 95% CI 2.49 - 6.68), and outside the neighborhood (OR 2.03 95% CI 1.59 - 2.59). Although significant risk exists at each scale, neighborhood scale risk factors best explained disease exposure. Analysis of variance revealed risk at the neighborhood scale was 57% greater than risk at the yard scale and 101% greater than risk outside the neighborhood.

Conclusions: This analysis emphasizes the importance of understanding and reducing tick-borne disease risk at the neighborhood scale. Risk-reducing interventions applied at each scale could be effective, but interventions applied at the neighborhood scale are most likely to protect human health.

Trial registration: The study was registered with PROSPERO: CRD42017079169 .

Keywords: Anaplasmosis; Babesiosis; Ixodes scapularis; Lyme disease; Peri-domestic; Spatial scale; Tick bites.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Animals
  • Humans
  • Ixodes / physiology
  • Lyme Disease / diagnosis
  • Lyme Disease / epidemiology
  • North America / epidemiology
  • Odds Ratio
  • Residence Characteristics / statistics & numerical data
  • Risk Factors
  • Tick Bites / diagnosis*
  • Tick Bites / epidemiology
  • Tick-Borne Diseases / diagnosis*
  • Tick-Borne Diseases / epidemiology