Emerging infectious diseases have become a rapidly increasing public health threat over the past 4 decades with the majority of pathogens being zoonotic or vector borne. Ticks are the second most important vector of disease globally, behind mosquitoes, and transmit a more diverse group of pathogens of medical importance than any other vector. Tick-borne diseases (TBDs) represent the most common vector-borne disease threats in North America, impacting both human and animal health. In Minnesota, the Lyme disease agent, Borrelia burgdorferi, emerged in 1980 and over the past two decades, incidence has risen over 700%. In order to better understand the local eco-epidemiology of these pathogens in the Twin Cities metro area a holistic approach to their ecology must be taken into account. The pathobiome concept has been introduced to ecological research to move beyond the ‘one pathogen= one disease’ principle. Pathogens must be evaluated within the framework of the microbial communities in which they exists. The impact of these communities can significantly drive disease transmission and vector competence. There are many gaps in data that currently exist in regards to the Ixodes scapularis pathobiome. To fill existing knowledge gaps, data were collected from the Metropolitan Mosquito Control District which had been trapping rodents and collecting ticks in the metro area since 1991. First, the pathobiome of Ixodes scapularis ticks was described. The analysis revealed significant changes depending upon the year ticks were collected. Next, tick and mammal population changes from 1993-2013 were analyzed to determine host vector relationships as well as vector range expansion. Ixodes scapularis have greatly expanded their range around the twin cities; however, urban development may have impacted that expansion. Additionally, the role of the Eastern chipmunk was shown to be important in local TBD ecology, and there is evidence of possible competition between tick species. Lastly, the impact of host blood meal and pathogen acquisition on the pathobiome of I. scapularis was examined. Both pathogens and host meal had a significant impact on tick pathobiome. The results from these studies are a step towards better understanding tick and TBD ecology and hopefully predicting and mitigating future transmission risk.
University of Minnesota Ph.D. dissertation. September 2017. Major: Environmental Health. Advisors: Craig Hedberg, Katey Pelican. 1 computer file (PDF); ix, 122 pages.
The Complex Eco-Epidemiology of Tick Borne Disease: Ticks, Hosts and Pathobiomes in an Urbanizing Environment.
Retrieved from the University of Minnesota Digital Conservancy,
Content distributed via the University of Minnesota's Digital Conservancy may be subject to additional license and use restrictions applied by the depositor.