Patrick Leighton

Patrick Leighton
Université de Montréal | UdeM · Faculty of Veterinary Medicine

BSc, PhD

About

87
Publications
9,617
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,444
Citations
Introduction
My research is connected by two major themes: 1) the ecology of zoonotic diseases and 2) the influence of animal ecology and landscape structure on the spatial pattern of species interactions (e.g. predation, disease transmission). Current research is focused on understanding the ecology of parasites and zoonotic pathogens of public health significance (e.g. Lyme disease, Rabies virus, and West Nile virus) and predicting their geographic spread, particularly in the context of climate change.

Publications

Publications (87)
Article
Public health management of Lyme disease (LD) is a dynamic challenge in Canada. Climate warming is driving the northward expansion of suitable habitat for the tick vector, Ixodes scapularis. Information about tick population establishment is used to inform the risk of LD but is challenged by sampling biases from surveillance data. Misclassifying ar...
Article
Full-text available
The development of interventions that reduce Lyme disease incidence remains a challenge. Reservoir-targeted approaches aiming to reduce tick densities or tick infection prevalence with Borrelia burgdorferi have emerged as promising ways to reduce the density of infected ticks. Acaricides of the isoxazoline family offer high potential for reducing i...
Article
The small Indian mongoose (Urva auropunctata) is a non-native invasive species across the Caribbean and a rabies reservoir on at least four islands in the region. Although previous studies reported mongoose density estimates in their non-native range, the variability in trapping designs, study seasonality, and analytical methods among studies precl...
Article
Full-text available
Lyme disease (LD) is a tick-borne disease which has been emerging in temperate areas in North America, Europe, and Asia. In Quebec, Canada, the number of human LD cases is increasing rapidly and thus surveillance of LD risk is a public health priority. In this study, we aimed to evaluate the ability of active sentinel surveillance to track spatiote...
Article
Lyme disease is an emerging public health threat in Ontario, Canada due to ongoing range expansion of the tick vector, Ixodes scapularis. Tick density is an important predictor of human Lyme disease risk and is typically measured using active tick surveillance via drag sampling, which is time and resource-intensive. New cost-effective tools are nee...
Article
Full-text available
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,...
Article
Full-text available
As the incidence of tick-borne diseases has sharply increased over the past decade, with serious consequences for human and animal health, there is a need to identify ecological drivers contributing to heterogeneity in tick-borne disease risk. In particular, the relative importance of animal host dispersal behaviour in its three context-dependent p...
Article
Full-text available
Weather and land use can significantly impact mosquito abundance and presence, and by consequence, mosquito-borne disease (MBD) dynamics. Knowledge of vector ecology and mosquito species response to these drivers will help us better predict risk from MBD. In this study, we evaluated and compared the independent and combined effects of weather and l...
Article
The incidence of Lyme disease is increasing in Québec and is closely linked to the distribution of Ixodes scapularis ticks. A time-to-establishment model developed in 2012 by Leighton and colleagues predicted the year of tick population establishment for each municipality in eastern Canada. To validate if this model correctly predicted tick distrib...
Preprint
Empirical observations and mathematical models show that climate warming can lead to the northern (or, more generally, poleward) spread of host species ranges and their corresponding diseases. Here, we explore an unexpected possibility whereby climate warming induces disease spread in the opposite direction to the directional shift in the host spec...
Preprint
Empirical observations and mathematical models show that climate warming can lead to the northern (or, more generally, poleward) spread of host species ranges and their corresponding diseases. Here, we explore an unexpected possibility whereby climate warming induces disease spread in the opposite direction to the directional shift in the host spec...
Preprint
Full-text available
Weather and land use can significantly impact mosquito abundance and presence, and by consequence, mosquito-borne disease (MBD) dynamics. Knowledge of vector ecology and mosquito species response to these drivers will help us better predict risk from MBD. In this study, we evaluated and compared the independent and combined effects of weather and l...
Poster
Tick vectors of multiple human diseases (Lyme disease, babesiosis, anaplasmosis, ehrlichiosis) continue to expand in North America. We developed an ensemble of statistical and mechanistic models to predict the number of host-seeking ticks at seven National Ecological Observation Network (NEON) sites, as part of the Ecological Forecasting Initiative...
Article
Full-text available
Lyme disease is a growing public health problem in Québec. Its emergence over the last decade is caused by environmental and anthropological factors that favour the survival of Ixodes scapularis, the vector of Lyme disease transmission. The objective of this study was to estimate the speed and direction of human Lyme disease emergence in Québec and...
Article
The tick vector of Lyme disease, Ixodes scapularis, is currently expanding its geographical distribution northward into southern Canada driving emergence of Lyme disease in the region. Despite large-scale studies that attributed different factors such as climate change and changes in land use to the geographical expansion of the tick, a comprehensi...
Article
Full-text available
Current climatic conditions limit the distribution of Aedes (Stegomyia) albopictus (Skuse, Diptera: Culicidae) in the north, but predictive climate models suggest this species could establish itself in southern Canada by 2040. A vector of chikungunya, dengue, yellow fever, Zika and West Nile viruses, the Ae. Albopictus has been detected in Windsor,...
Article
Vector-borne diseases (VBDs) are continuing to emerge globally, requiring new surveillance systems to follow increasing VBD risk for human populations. Sentinel surveillance is an approach that allows tracking of disease risk through time using limited resources. However, there is no consensus on how best to design a sentinel surveillance network i...
Article
Full-text available
An expected consequence of climate warming is an expansion of the geographical distribution of biting insects and associated arthropod-borne viruses (arboviruses). Emerging and re-emerging arboviruses that can affect human and animal health are likely to pose significant consequences for Northern communities where access to health resources is limi...
Article
Identifying ecological drivers of tick-borne pathogen spread has great value for tick-borne disease management. However, theoretical investigations into the consequences of host movement behaviour on pathogen spread dynamics in heterogeneous landscapes remain limited because spatially explicit epidemiological models that incorporate more realistic...
Preprint
Lyme disease is a growing public health problem in Québec. Its emergence over the last decade is caused by environmental and anthropological factors that favour the survival of Ixodes scapularis, the vector of Lyme disease transmission. The objective of this study was to estimate the speed and direction of Lyme disease emergence in Québec and to id...
Article
Full-text available
Arctic fox (Vulpes lagopus) and its tundra habitat are a unique system for the study of rabies virus epidemics. Contrary to theoretical calculations reporting a critical density (KT) of approximately 1 fox/km² for rabies endemicity, arctic rabies persists at densities below this. The calculation of KT = 1 fox/km² assumes uniform fox density across...
Article
We investigated intramuscular administration of alfaxalone (5.3–10.0 mg/kg) as an immobilizing agent in free‐ranging small Indian mongooses (Urva auropunctata) on the island of St. Kitts, West Indies. From 5–11 January 2020, we successfully immobilized 10 of 11 mongooses. Alfaxalone provided rapid onset (median = 3 min) of immobilization. Mean dura...
Article
Rabies occurs throughout the Arctic, representing an ongoing public health concern for residents of northern communities. The Arctic fox (Vulpes lagopus) is the main reservoir of the Arctic rabies virus variant, yet little is known about the epidemiology of Arctic rabies, such as the ecological mechanisms driving where and when epizootics in fox po...
Preprint
Full-text available
An expected consequence of climate warming is an expansion of the geographic distribution of biting insects and associated arthropod-borne diseases (arboviruses). Emerging and reemerging arboviruses that can affect human health are likely to pose significant consequences for Northern communities where access to health resources is limited. In the N...
Article
Full-text available
We applied the model-guided fieldwork framework to the Caribbean mongoose rabies system by parametrizing a spatially-explicit, individual-based model, and by performing an uncertainty analysis designed to identify parameters for which additional empirical data are most needed. Our analysis revealed important variation in output variables characteri...
Chapter
This book is a collection of 77 expert opinions arranged in three sections. Section 1 on "Climate" sets the scene, including predictions of future climate change, how climate change affects ecosystems, and how to model projections of the spatial distribution of ticks and tick-borne infections under different climate change scenarios. Section 2 on "...
Article
Full-text available
Background: Lyme disease is an emerging vector-borne zoonotic disease of increasing public health importance in Canada. As part of its mandate, the Canadian Lyme Disease Research Network (CLyDRN) launched a pan-Canadian sentinel surveillance initiative, the Canadian Lyme Sentinel Network (CaLSeN), in 2019. Objectives: To create a standardized, n...
Article
Full-text available
Blacklegged ticks (Ixodes scapularis) are considered to be the main vector of Lyme disease in eastern North America. They may parasitize a wide range of bird and mammal hosts. Northward dispersal of blacklegged ticks has been attributed largely to movement of hosts to areas outside of the current range of the tick, in conjunction with climate chang...
Article
Full-text available
Background: Lyme disease (LD) is an increasing public health threat in temperate zones of the northern hemisphere, yet relatively few methods exist for reducing LD risk in endemic areas. Disrupting the LD transmission cycle in nature is a promising avenue for risk reduction. This experimental study evaluated the efficacy of fluralaner, a recent ora...
Article
Full-text available
In eastern North America, including Canada, Lyme disease is caused by Borrelia burgdorferi sensu stricto and transmitted to humans by the blacklegged tick, Ixodes scapularis. The last decade has seen a growing incidence of Lyme disease in Canada, following the northward range expansion of I. scapularis tick populations from endemic areas in eastern...
Presentation
Lyme disease (LD) represent an important threat for public heath worldwide and an emerging threat in Canada. Yet, few methods exist to reduce the LD transmission risk in endemic area. A promising avenue to achieve risk reduction is the disruption of LD transmission cycle in nature by treating the small rodent reservoirs of its etiological agent, th...
Article
Rabies is a major issue for human and animal health in the Arctic, yet little is known about its epidemiology. In particular, there is an ongoing debate regarding how Arctic rabies persists in its primary reservoir host, the Arctic fox (Vulpes lagopus), which exists in the ecosystem at very low population densities. To shed light on the mechanisms...
Poster
Context. Lyme disease (LD) is an important North American tick-born disease that is emerging in Canada. In parallel, new effective drugs against ticks like fluralaner, an Isoxazoline, appear on the market. Objective. Reduce LD transmission risk to humans by treating ecological reservoirs of its etiological agent with fluralaner. Methodology. Evalua...
Article
Full-text available
Background Toxoplasma gondii, a zoonotic protozoan parasite, infects mammals and birds worldwide. Infection in humans is often asymptomatic, though illnesses can occur in immunocompromised hosts and the fetuses of susceptible women infected during pregnancy. In Nunavik, Canada, 60% of the Inuit population has measurable antibodies against T. gondii...
Article
Full-text available
Lyme disease, the most commonly reported vector-borne disease in North America, is caused by the spirochete Borrelia burgdorferi sensu stricto, which is transmitted by Ixodes scapularis in eastern Canada and Ixodes pacificus in western Canada. Recently, the northward range expansion of I. scapularis ticks, in south-eastern Canada, has resulted in a...
Article
Since 2002, human cases of West Nile virus (WNV) have occurred every year in southern Canada, but WNV risk remains challenging to predict. Here, we explored the ability of weather-based forecasting models to predict the seasonal abundance of two WNV vector species (Culex pipiens-restuans and Aedes vexans) in Québec, Canada, and explored the importa...
Article
Full-text available
Significant global ecological changes continue to drive emergence of tick-borne zoonoses around the world. This poses an important threat to both human and animal health, and highlights the need for surveillance systems that are capable of monitoring these complex diseases effectively across different stages of the emergence process. Our objective...
Article
Full-text available
Dogs have been an integral part of the Inuit social and cultural environment for generations, but their presence also generates public health risks such as bites and exposure to zoonotic diseases such as rabies. In Nunavik, Canada, some prevention and control interventions targeting dogs have been implemented but have not demonstrated their effecti...
Article
Full-text available
Context In the ecology of Lyme disease emergence, it remains unclear to what extent spread of the tick vector (Ixodes scapularis) and the pathogen (Borrelia burgdorferi) are dependent upon the dispersal of vertebrate hosts in spatially heterogeneous landscapes. Yet, empirical measure of these complex ecologically driven spread processes present con...
Article
Full-text available
Climate change is driving emergence and establishment of Ixodes scapularis, the main vector of Lyme disease in Québec, Canada. As for the black-legged tick, I. scapularis Say, global warming may also favor northward expansion of other species of medically important ticks. The aims of this study were to determine (1) current diversity and abundance...
Article
Full-text available
Background: The risk of contracting Lyme disease (LD) can vary spatially because of spatial heterogeneity in risk factors such as social-behavior and exposure to ecological risk factors. Integrating these risk factors to inform decision-making should therefore increase the effectiveness of mitigation interventions. Objectives: The objective of t...
Article
Individual vigilance against threats typically decreases with group size. However, group size often explains a small amount of variation in vigilance suggesting that other factors such as individual differences might contribute. For instance, individuals could maintain different vigilance levels overall and also respond differently to variation in...
Article
Full-text available
Since its detection in Canada in the early 1990s, Ixodes scapularis, the primary tick vector of Lyme disease in eastern North America, has continued to expand northward. Estimates of the tick’s broad-scale distribution are useful for tracking the extent of the Lyme disease risk zone; however, tick distribution may vary widely within this zone. Here...
Article
Full-text available
Background: Lyme disease (LD) is a bacterial infection transmitted by the black-legged tick (Ixodes scapularis) in eastern North America. It is an emerging disease in Canada due to the expanding range of its tick vector. Environmental risk maps for LD, based on the distribution of the black-legged tick, have focused on coarse determinants such as...
Article
Lyme disease is an emerging public health threat in Canada. In this context, rapid detection of new risk areas is essential for timely application of prevention and control measures. In Canada, information on Lyme disease risk is collected through three surveillance activities: active tick surveillance, passive tick surveillance, and reported human...
Article
Full-text available
The invasion of the blacklegged tick, Ixodes scapularis into Ontario, Canada poses a significant risk to public health because it is a vector for numerous pathogens, including Borrelia burgdorferi sensu stricto, the causative agent of Lyme disease. Baseline field sampling in 2014 and 2015 detected I. scapularis and B. burgdorferi at sites across so...
Data
Comparison of the I. scapularis site status over two years of field sampling with the predicted year to establishment based on Leighton et al. (2012) at 33 sites in Ontario. (DOCX)
Data
The univariable analysis of site-level ecological variables on the late establishment of I. scapularis at 33 sites sampled in Ontario during the spring, summer and fall of 2014 or 2015 and again in 2016 based on logistic regression or exact logistic regression (*). (DOCX)
Article
In group-foraging species with no alarm signals, the sudden departure of neighbours can be used to inform the rest of the group about the detection of a threat. However, sudden departures are ambiguous because they can be triggered by factors unrelated to predator detection. We evaluated how animals react to the sudden departure of neighbours in gr...
Article
Full-text available
Background Lyme disease (LD), a multisystem infection caused by the spirochete Borrelia burgdorferi sensu stricto (B. burgdorferi), is the most reported vector-borne disease in North America, and by 2020, 80% of the population in central and eastern Canada could live in LD risk areas. Among the key factors for minimising the impact of LD are the ac...
Poster
Full-text available
In Nunavik, the role of domestic dogs in harbouring and transmitting gastrointestinal parasites to people is poorly documented. The objectives of our study were to: 1) document spatio-temporal activity patterns of the Kuujjuaq dog population 2) measure the prevalence of gastrointestinal parasites in dogs 3) determine what factors influence parasiti...
Article
Ixodes scapularis, the main vector of Borrelia burgdorferi, the spirochetal agent of Lyme disease, is expanding its range in southern Canada and bringing risk to the public from Lyme disease. The aims of this study were to i) describe how risk of Lyme disease in Quebec, Canada, has changed from 2008 to 2014 by analysis of the number of tick submiss...
Article
In Canada, Francisella tularensis , the zoonotic bacterial agent of tularemia, affects mostly snowshoe hares ( Lepus americanus ), muskrats ( Ondatra zibethicus ), and beavers ( Castor canadensis ). Despite numerous studies, the ecologic cycle and natural reservoirs of F. tularensis are not clearly defined. We conducted a cross-sectional study to e...
Article
Full-text available
In North America, Lyme disease (LD) is a tick-borne zoonosis caused by the spirochaete bacterium Borrelia burgdorferi sensu stricto (s.s.), which is maintained by wildlife. Tick vectors and bacteria are currently spreading into Canada and causing increasing numbers of cases of LD in humans and raising a pressing need for public health responses. Th...
Article
From April to July 2005, rectal swabs were collected from 48 free-ranging small Asian mongooses (Herpestes javanicus) on the east and south coasts of Barbados and analyzed for Salmonella and Campylobacter spp. Salmonella was recovered in 21.12% (7/33) of mongooses at the east-coast site and 26.67% (4/15) at the south-coast site. Four serotypes were...
Data
Figure S1. Current (A) and future (B) predicted abundance (the maximum annual number of feeding female ticks at equilibrium) of the black-legged tick, based on DD > 0.
Data
Figure S2. Probability of presence for the current (A) and future (B) projected distribution of the white-footed mouse, based on climatic variables.