Transmission patterns of tick-borne pathogens among birds and rodents in a forested park in southeastern Canada

Abstract

Ixodes scapularis ticks are expanding their range in parts of northeastern North America, bringing with them pathogens of public health concern. While rodents like the white-footed mouse, Peromyscus leucopus, are considered the primary reservoir of many emerging tick-borne pathogens, the contribution of birds, as alternative hosts and reservoirs, to local transmission cycles has not yet been firmly established. From 2016 to 2018, we collected host-seeking ticks and examined rodent and bird hosts for ticks at 48 sites in a park where blacklegged ticks are established in Quebec, Canada, in order to characterize the distribution of pathogens in ticks and mammalian and avian hosts. We found nearly one third of captured birds (n = 849) and 70% of small mammals (n = 694) were infested with I. scapularis. Five bird and three mammal species transmitted Borrelia burgdorferi to feeding larvae (n larvae tested = 2257) and we estimated that about one fifth of the B. burgdorferi-infected questing nymphs in the park acquired their infection from birds, the remaining being attributable to mice. Ground-foraging bird species were more parasitized than other birds, and species that inhabited open habitat were more frequently infested and were more likely to transmit B. burgdorferi to larval ticks feeding upon them. Female birds were more likely to transmit infection than males, without age differentiation, whereas in mice, adult males were more likely to transmit infection than juveniles and females. We also detected Borrelia miyamotoi in larvae collected from birds, and Anaplasma phagocytophilum from a larva collected from a white-footed mouse. This study highlights the importance of characterising the reservoir potential of alternative reservoir hosts and to quantify their contribution to transmission dynamics in different species assemblages. This information is key to identifying the most effective host-targeted risk mitigation actions.

Artificial Feeding Systems for Vector-Borne Disease Studies

“…Studies on Chagas disease and Yellow fever virus showcase the relevance of NHPs in closely replicating human disease progression [ 53 , 54 ], despite challenges in handling and monitoring, the need for specialized facilities, ethical considerations, and cost implications [ 55 ]. A number of birds, such as the Eurasian blackbird, house sparrow, American robin, and domestic chicken, have provided information about the interactions between viruses like St. Louis encephalitis virus and West Nile virus and their reservoir hosts [ 39 , 56 , 57 , 58 , 59 ].…”

Pharmacological studies and pharmacokinetic modelling to support the development of interventions targeting ecological reservoirs of Lyme disease

“…In addition to their role as reservoir, Peromyscus mice are major hosts for I . scapularis larvae and nymphs 2 , 5 , 6 . Thus, they play a key role in the transmission of B .…”

Historical associations and spatiotemporal changes of pathogen presence in ticks in Canada: A systematic review

“…This pathogen was first detected in ticks and white-footed mice in the late 1980s in Ontario (Barker et al, 1992;Lindsay et al, 1991). In 2012, Borrelia miyamotoi, the bacterium causing tick-borne relapsing fever, was first identified in I. scapularis ticks, but it has now been found in several Canadian provinces (Dibernardo et al, 2014;Dumas et al, 2022;Wilson et al, 2022;Zinck & Lloyd, 2022). Anaplasma bacteria cause anaplasmosis in wildlife and humans with species such as A. phagocytophilum geographically widespread across Canada and isolated cases of Anaplasma marginale and A. bovis occurring in Alberta and Saskatchewan (Chilton et al, 2018;Dergousoff & Chilton, 2011;Howden et al, 2010;Wilson et al, 2022).…”

“…Migratory birds disperse adventitious ticks over long distances, allowing them to establish in new locations (Ogden et al., 2015; Scott, Clark, Foley, Bierman & Durden, 2018). In addition, several bird species in Canada are competent reservoirs for Anaplasma , Babesia , and Borrelia species (Dumas et al., 2022; Munro et al., 2019; Scott et al., 2020). Regionally, tick vectors are dispersed short distances by the range shifts of vertebrate hosts (Diuk‐Wasser et al., 2021; Roy‐Dufresne et al., 2013).…”

“…In 2012, Borrelia miyamotoi , the bacterium causing tick‐borne relapsing fever, was first identified in I . scapularis ticks, but it has now been found in several Canadian provinces (Dibernardo et al., 2014; Dumas et al., 2022; Wilson et al., 2022; Zinck & Lloyd, 2022). Anaplasma bacteria cause anaplasmosis in wildlife and humans with species such as A .…”