The ongoing invasion of the Lyme disease bacteria, Borrelia burgdorferi (Bb), in the United States presents a significant public health risk as well a a unique opportunity to study the process of ongoing pathogen emergence. Lyme disease is the most prevalent vector-borne disease in the USA and is rapidly emerging out of two disease foci in the Northeast and Midwest. Despite its epidemiological importance, knowledge of the source and trajectory of the current Bb invasion remains speculative, restricted to anecdotal case reports, and limited entomological surveys. It is critical to determine the origin and pathway of the current invasion to inform predictions about areas of further spread and improve disease control efforts. Phylogeographic approaches enable high-resolution study of epidemiologically important pathogens and include powerful methods for reconstructing the history of pathogen invasion and inferring epidemic origins, routes of invasion, and rates of spatial spread. Further, advances in next-generation sequencing (NGS) has made the generation of whole genome sequences (WGS) at the population-level efficient and cost-effective for study of pathogen genomic variation on epidemic timescales. However, the power of NGS and recent advances in Bayesian phylogeography, have not yet been harnessed for population genomic study of Bb, nor to investigate the evolutionary dynamics of Bb emergence. This study seeks to reconstruct the invasion history of the Lyme disease spirochete, Borrelia burgdorferi (Bb), to better understand the ecological and environmental drivers of Bb emergence and to inform predictions about continued pathogen spread. The proposed research will (1) use novel hybrid capture methods to obtain WGS of Bb directly from field- collected tick samples and allows identification of genome wide Single Nucleotide Polymorphisms (SNPs) that will be used to (2) reconstruct the history of Bb emergence across two spatial scales. The proposed research provides an important training opportunity in field study design, pathogen genomics, and phylogeographic analysis.

Public Health Relevance

The ongoing invasion of the Lyme disease bacteria, Borrelia burgdorferi, in the United States presents a significant public health risk as well as a unique opportunity to study the process of ongoing pathogen emergence. This study uses whole genome sequences and high-resolution phylogeographic analysis to reconstruct the invasion history of B. burgdorferi, identify the source(s) and trajectory of emergence, infer the ecological and environmental drivers of spread, and inform predictions about continued pathogen spread.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
1F31AI118233-01A1
Application #
9051058
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Ilias, Maliha R
Project Start
2015-12-16
Project End
2017-12-15
Budget Start
2015-12-16
Budget End
2016-12-15
Support Year
1
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Yale University
Department
Public Health & Prev Medicine
Type
Graduate Schools
DUNS #
043207562
City
New Haven
State
CT
Country
United States
Zip Code
Walter, Katharine S; Carpi, Giovanna; Evans, Benjamin R et al. (2016) Vectors as Epidemiological Sentinels: Patterns of Within-Tick Borrelia burgdorferi Diversity. PLoS Pathog 12:e1005759
Walter, Katharine S; Pepin, Kim M; Webb, Colleen T et al. (2016) Invasion of two tick-borne diseases across New England: harnessing human surveillance data to capture underlying ecological invasion processes. Proc Biol Sci 283: