Diseases that are transmitted from animals to humans are the most prevalent type of emerging infectious diseases threatening public health. Lyme disease, caused by the bacterium Borrelia burgdorferi, affects more people than any other arthropod-borne disease (carried by insects or ticks) in the US. The number of human cases continues to rise as the geographic range affected by the bacteria expands. Although managing Lyme disease through vaccination appears many years off, identifying environmental factors that promote the growth and spread of the bacterium or the tick vector, Ixodes scapularis, will aid in developing ecological control strategies that can be effective and long-term solutions to reducing Lyme disease incidence. The major goal of this proposal is to unravel the complex interactions between both B. burgdorferi and I. scapularis and their natural environments that have resulted in the recent increase in the geographic range of Lyme disease. We will investigate the temporal and spatial heterogeneity of B. burgdorferi and I. scapularis in a natural ecosystem and assess the biotic, abiotic, and historical factors that have given rise to that heterogeneity. Identifying and quantifying the effects of these interactions will lead to important insights into the biology and ecology of B. burgdorferi and I. scapularis and ultimately to novel targets for ecological control strategies. We will utilize the rapidly developing statistical tools of phylogeography and landscape genetics to analyze a sample of ticks and bacteria that were collected during the time period that Lyme disease was establishing in the study area. We will use the knowledge gained to develop and experimentally validate predictive models of the spread of Lyme disease into novel environments in the future. In the near term, these studies can lead to a mechanistic understanding of how the environmental factors in a real ecosystem determine the realized geographic range of Lyme disease;few examples are known of a functional basis determining the rate and direction of dispersal of a pathogen and its vector in nature. From a global disease ecology perspective, this work is imperative as the geographic ranges of many infectious diseases are rapidly increasing and encroaching into human communities. These studies will furnish fundamental new insights into factors affecting the geographic spread of, and disease risk from, animal-transmitted pathogens. Our long-term goal is to determine the mechanisms contributing to human Lyme disease risk that could be targeted by ecological control strategies.

Public Health Relevance

Lyme disease is the most prevalent insect or tick transmitted disease in the US. The number of cases continues to rise as the geographic range affected by the bacteria expands. We will identify and quantify the effects of biotic, abiotic, and historical factors on the rate of geographic expansion of Lyme disease. This research will lead to important insights into the biology and ecology of the bacteria and tick vector of Lyme disease and ultimately to novel targets for ecological control strategies.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
Project #
Application #
Study Section
Genetic Variation and Evolution Study Section (GVE)
Program Officer
Breen, Joseph J
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Pennsylvania
Schools of Arts and Sciences
United States
Zip Code
Linden, Jeanne V; Prusinski, Melissa A; Crowder, Lauren A et al. (2018) Transfusion-transmitted and community-acquired babesiosis in New York, 2004 to 2015. Transfusion 58:660-668
Loy, Dorothy E; Plenderleith, Lindsey J; Sundararaman, Sesh A et al. (2018) Evolutionary history of human Plasmodium vivax revealed by genome-wide analyses of related ape parasites. Proc Natl Acad Sci U S A 115:E8450-E8459
Khatchikian, Camilo E; Nadelman, Robert B; Nowakowski, John et al. (2017) The impact of strain-specific immunity on Lyme disease incidence is spatially heterogeneous. Diagn Microbiol Infect Dis 89:288-293
Zhou, Wei; Brisson, Dustin (2017) Correlation between antigenicity and variability in the vls antigenic variation system of Borrelia burgdorferi. Microbes Infect 19:267-276
Zhou, Wei; Brisson, Dustin (2017) Interactions between host immune response and antigenic variation that control Borrelia burgdorferi population dynamics. Microbiology 163:1179-1188
Clarke, Erik L; Sundararaman, Sesh A; Seifert, Stephanie N et al. (2017) swga: a primer design toolkit for selective whole genome amplification. Bioinformatics 33:2071-2077
Adalsteinsson, Solny A; D'Amico, Vincent; Shriver, W Gregory et al. (2016) Scale-dependent effects of nonnative plant invasion on host-seeking tick abundance. Ecosphere 7:
Sundararaman, Sesh A; Plenderleith, Lindsey J; Liu, Weimin et al. (2016) Genomes of cryptic chimpanzee Plasmodium species reveal key evolutionary events leading to human malaria. Nat Commun 7:11078
Prusinski, M A; Mertins, J W; Meehan, L J (2015) Two Gynandromorphs of Ixodes scapularis (Acari: Ixodidae) from New York State. J Med Entomol 52:278-82
Khatchikian, Camilo E; Foley, Erica A; Barbu, Corentin M et al. (2015) Population structure of the Chagas disease vector Triatoma infestans in an urban environment. PLoS Negl Trop Dis 9:e0003425

Showing the most recent 10 out of 26 publications