Host Disease and Environmental Factors Associated with Zoonotic Pathogens in Urban Norway Rats (Rattus norvegicus)

dc.contributor.advisorJardine, Claire
dc.contributor.authorRothenburger, Jamie Lee
dc.date.accessioned2017-12-18T13:57:59Z
dc.date.available2018-11-27T06:00:26Z
dc.date.copyright2017-11
dc.date.created2017-11-27
dc.date.issued2017-12-18
dc.degree.departmentDepartment of Pathobiologyen_US
dc.degree.grantorUniversity of Guelphen_US
dc.degree.nameDoctor of Philosophyen_US
dc.degree.programmePathobiologyen_US
dc.description.abstractThe purpose of this research was to investigate the role of environmental and intra-host factors in the epidemiology and ecology of zoonotic pathogen carriage by urban Norway rats (Rattus norvegicus). Rats are the hosts of many zoonotic pathogens, including Yersinia pestis and Leptospira interrogans, the causative agents of plague and leptospirosis, respectively. Knowledge of the ecology and epidemiology of zoonotic pathogens in their rat hosts is important for understanding and mitigating the risk to people. Most studies of rat-associated zoonotic pathogens investigate rat demographic characteristics. But many factors across hierarchical levels of biological organization can influence pathogens in hosts. These include environmental and intra-host factors such as co-infections and disease. Using samples and data collected during a year-long trap and removal study of rats set in Vancouver, British Columbia, I first assessed microenvironmental features, time-lagged weather variables and rat abundance for associations with four potentially zoonotic pathogens carried by rats (Bartonella tribocorum, Clostridium difficile, antimicrobial resistant Escherichia coli and methicillin-resistant Staphylococcus aureus). Significant factors included temperature, precipitation, specific land use and pavement condition. No pathogens were associated with rat abundance. These results may inform predictive modeling, targeted surveillance activities and specific interventions. Next, I used pathological analyses to document the spectrum of macroscopic and microscopic disease found in these rats. The most severe and frequent lesions were infectious and inflammatory. Finally, I assessed the most common lesions and parasite infections for associations with three zoonotic pathogens (B. tribocorum, C. difficile and L. interrogans). Parasite infections were associated with B. tribocorum, while C. difficile and L. interrogans were associated with specific lesions, and rats were rarely co-infected with multiple zoonotic pathogens. The impact of the environment, weather, lesions and parasitic infections varied depending on the zoonotic pathogen. Collectively, these results suggest a possible dynamic interplay among these factors, adding to the growing knowledge of zoonotic pathogen ecology in rats. The disease ecology methods and concepts developed by this research are broadly applicable to the study of the epidemiology and ecology of zoonoses in other hosts and ecosystems.en_US
dc.description.sponsorshipCanadian Institutes of Health Research
dc.identifier.urihttp://hdl.handle.net/10214/12090
dc.language.isoenen_US
dc.publisherUniversity of Guelphen_US
dc.rightsAttribution-NonCommercial-NoDerivs 2.5 Canada*
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/2.5/ca/*
dc.subjectepidemiologyen_US
dc.subjectdisease ecologyen_US
dc.subjectwildlifeen_US
dc.subjectratsen_US
dc.subjectNorway raten_US
dc.subjectRattus norvegicusen_US
dc.subjectRattusen_US
dc.subjectenvironmenten_US
dc.subjectweatheren_US
dc.subjectpathologyen_US
dc.subjectdiseaseen_US
dc.subjectzoonosesen_US
dc.subjectbacteriaen_US
dc.subjecttemperatureen_US
dc.subjectprecipitationen_US
dc.subjectco-infectionen_US
dc.subjectlesionen_US
dc.subjectparasiteen_US
dc.titleHost Disease and Environmental Factors Associated with Zoonotic Pathogens in Urban Norway Rats (Rattus norvegicus)en_US
dc.typeThesisen_US

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