Host Population Dynamics Research Articles

Space and time predictions of schistosomiasis snail host population dynamics across hydrologic regimes in Burkina Faso.

The ecology of the aquatic snails that serve as obligatory intermediate hosts of human schistosomiasis is driven by climatic and hydrological factors which result in specific spatial patterns of occurrence and abundance. These patterns in turn affect, jointly with other determinants, the geography of the disease and the timing of transmission windows, with direct implications for the success of control and elimination programmes in the endemic countries. We address the spatial distribution of the intermediate hosts and their seasonal population dynamics within a predictive ecohydrological framework developed at the national scale for Burkina Faso, West Africa. The approach blends river network-wide information on hydrological ephemerality which conditions snail habitat suitability together with ensembles of discrete time ecological models forced by remotely sensed estimates of temperature and precipitation. The models were validated against up to four years of monthly snail abundance data. Simulations of model ensembles accounting for the uncertainty in remotely sensed products adequately reproduce observed snail demographic fluctuations observed in the field across habitat types, and produce national scale predictions by accounting for spatial patterns of hydrological conditions in the country. Geospatial estimates of seasonal snail abundance underpin large-scale, spatially explicit predictions of schistosomiasis incidence. This work can therefore contribute to the development of disease control and elimination programmes.

Population dynamics of fresh water snail intermediate hosts of <i>Schistosoma spp.,</i> in the Federal Capital Territory, Abuja, Nigeria

This study was carried out to provide information on the population dynamics of the snail intermediate host of Schistosoma spp., in Abuja. A cross-sectional study was carried out on water bodies with high human contact activities in all the six area councils in Federal Capital Territory including; Narachi, Rafir shawa, Shetiko, Ushafa, Yangoji and Basa Rivers in Abaji, Gwagwalada, Kuje, Bwari, Kwali and Abuja Municipal Area Council respectively. Sampling of snail was based on convenience and presence of snail in the selected areas. Each settlement in the sample population was visited once monthly between March and September, 2017 for snail sample collection. A total of 766 fresh water snails identified to be snail intermediate hosts of schistosomiasis were collected during the study. The prevalence of fresh water snail intermediate hosts of Schistosoma spp., in Abuja comprises 30.16% Bulinus globosus, 11.75% of Bulinus truncatus and 58.09% of Biomphilaria pfeifferi. These fresh water snails were found to be more prevalent in the month of March in all the Local Government Area Council sampled with Gwagwalada Area Council having the highest prevalence of fresh water snail while Bwari Area Council had the lowest. This study revealed that there was high prevalence of snail intermediate hosts of schistosomiasis in Abuja. Hence, there is need for appropriate intervention by the Federal Ministry of Health (FMOH), in collaboration with the National Schistosomiasis Control Program (NSCP) to control snail intermediate hosts of Schistosomes spp., in the study-area using chemical or biological molluscide.Keywords: Water bodies; human contact; Schistosoma spp

Intrinsic and extrinsic drivers of transmission dynamics of hemorrhagic fever with renal syndrome caused by Seoul hantavirus.

Seoul hantavirus (SEOV) has recently raised concern by causing geographic range expansion of hemorrhagic fever with renal syndrome (HFRS). SEOV infections in humans are significantly underestimated worldwide and epidemic dynamics of SEOV-related HFRS are poorly understood because of a lack of field data and empirically validated models. Here, we use mathematical models to examine both intrinsic and extrinsic drivers of disease transmission from animal (the Norway rat) to humans in a SEOV-endemic area in China. We found that rat eradication schemes and vaccination campaigns, but below the local elimination threshold, could diminish the amplitude of the HFRS epidemic but did not modify its seasonality. Models demonstrate population dynamics of the rodent host were insensitive to climate variations in urban settings, while relative humidity had a negative effect on the seasonality in transmission. Our study contributes to a better understanding of the epidemiology of SEOV-related HFRS, demonstrates asynchronies between rodent population dynamics and transmission rate, and identifies potential drivers of the SEOV seasonality.

Testing for loss of Epichloë and non-epichloid symbionts under altered rainfall regimes.

Microbial symbionts can buffer plant hosts from environmental change. Therefore, understanding how global change factors alter the associations between hosts and their microbial symbionts may improve predictions of future changes in host population dynamics and microbial diversity. Here, we investigated how one global change factor, precipitation, affected the maintenance or loss of symbiotic fungal endophytes in a C3 grass host. Specifically, we examined the distinct responses of Epichloë (vertically transmitted and systemic) and non-epichloid endophytes (typically horizontally transmitted and localized) by considering (1) how precipitation altered associations with Epichloë and non-epichloid endophytic taxa across host ontogeny, and (2) interactive effects of water availability and Epichloë on early seedling life history stages. We manipulated the presence of Epichloë amarillans in American beachgrass (Ammophila breviligulata) in a multiyear field experiment that imposed three precipitation regimes (ambient or ±30% rainfall). In laboratory assays, we investigated the interactive effects of water availability and Epichloë on seed viability and germination. Reduced precipitation decreased the incidence of Epichloë in leaves in the final sampling period, but had no effect on associations with non-epichloid taxa. Epichloë reduced the incidence of non-epichloid endophytes, including systemic p-endophytes, in seeds. Laboratory assays suggested that association with Epichloë is likely maintained, in part, due to increased seed viability and germination regardless of water availability. Our study empirically demonstrates several pathways for plant symbionts to be lost or maintained across host ontogeny and suggests that reductions in precipitation can drive the loss of a plant's microbial symbionts.

Importance of infection of haemosporidia blood parasites during different life history stages for long‐term reproductive fitness of collared flycatchers

The interaction between birds and haemosporidia blood parasites is a well‐used system in the study of parasite biology. However, where, when and how parasites are transmitted is often unclear and defining parasite transmission dynamics is essential because of how they influence parasite‐mediated costs to the host. In this study, we used cross‐sectional and longitudinal data taken from a collared flycatcher Ficedula albicollis population to investigate the temporal dynamics of haemosporidia parasite infection and parasite‐mediated costs to host fitness. We investigated host–parasite interactions starting at the nestling stage of the bird's life‐cycle and then followed their progress over three breeding attempts to quantify their fitness – measured as the number of offspring they produced that recruited back into the breeding population. We found that the majority of haemosporidia blood parasite infections occurred within the first year of life and that the most common parasite lineages that infected the breeding population also infected juvenile birds in the natal environment. Moreover, our findings suggest that collared flycatcher nestlings in poorer condition could be at a higher risk of haemosporidia blood parasite infection. In this study, only female and not male bird fitness was adversely affected by parasite infection and the cost of infection on female fitness depended on the timing of transmission. In conclusion, our study indicates that in collared flycatchers, early‐life is potentially important for many of the interactions with haemosporidia parasite lineages, and evidence of parasite‐mediated costs to fitness suggest that these parasites may have influenced the host population dynamics.

Multi-pathogen serological survey of migratory caribou herds: A snapshot in time

Pathogens can impact host survival, fecundity, and population dynamics even when no obvious disease is observed. Few baseline data on pathogen prevalence and diversity of caribou are available, which hampers our ability to track changes over time and evaluate impacts on caribou health. Archived blood samples collected from ten migratory caribou herds in Canada and two in Greenland were used to test for exposure to pathogens that have the potential to effect population productivity, are zoonotic or are emerging. Relationships between seroprevalence and individual, population, and other health parameters were also examined. For adult caribou, the highest overall seroprevalence was for alphaherpesvirus (49%, n = 722), pestivirus (49%, n = 572) and Neospora caninum (27%, n = 452). Lower seroprevalence was found for parainfluenza virus type 3 (9%, n = 708), Brucella suis (2%, n = 758), and Toxoplasma gondii (2%, n = 706). No animal tested positive for antibodies against West Nile virus (n = 418) or bovine respiratory syncytial virus (n = 417). This extensive multi-pathogen survey of migratory caribou herds provides evidence that caribou are exposed to pathogens that may have impacts on herd health and revealed potential interactions between pathogens as well as geographical differences in pathogen exposure that could be linked to the bio-geographical history of caribou. Caribou are a keystone species and the socio-economic cornerstone of many indigenous cultures across the North. The results from this study highlight the urgent need for a better understanding of pathogen diversity and the impact of pathogens on caribou health.

Wolbachia infection and parasitoid occurrence among plant-feeding caterpillars of the endangered butterfly Phengaris teleius (Lepidoptera: Lycaenidae) in southern Poland

Parasites are an important component of ecological communities, as they shape host population dynamics and interfere with interspecific competition in ecosystems. Here, we studied Wolbachia infection and parasitoid occurrence among caterpillars of the endangered Phengaris teleius butterfly in five populations inhabiting southern Poland. The knowledge about potential parasites of P. teleius may be of particular importance for understanding forces regulating population processes of this species. Our study showed lack of Wolbachia infection and endoparasitoids in the sample of 91 4th instar P. teleius caterpillars. However, we found larvae of an unidentified hymenopteran ectoparasitoid on 17 3rd and 4th instar P. teleius caterpillars. We compare our results to findings from other populations of P. teleius, and its sister species in Europe and Asia, and discuss possible causes of observed patterns of parasite occurrence.

Dynamics of Amoebophrya parasites during recurrent blooms of the ichthyotoxic dinoflagellate Cochlodinium polykrikoides in Korean coastal waters

During the bloom events of the harmful dinoflagellate Cochlodinium polykrikoides in August and October, 2012, infections by two different Amoebophrya species were observed in Korean coastal waters. To investigate the dynamics of the two parasites and their relative impact on the host populations, a quantitative real-time PCR (qPCR) method was applied to detect and quantify the parasites in the free-living and parasitic stages. Each specific primer set of the target species, Amoebophrya sp. 1 and sp. 2 was designed on the large subunit (LSU) and the first internal transcribed spacer (ITS1) of ribosomal RNA (rRNA) gene, respectively. Dynamics of the two Amoebophrya species via qPCR assay showed distinct patterns during the C. polykrikoides bloom events. Amoebophrya sp. 1 showed peaks during both bloom events in August and October with relatively low copies (106 to 107 copies L−1), while Amoebophrya sp. 2 appeared only during the bloom event in October with very high copies (109 to 1010 copies L−1). Overall, the qPCR measurements for the dynamics of two Amoebophrya species in the parasitic stage (> 5 μm fractions) were consistent with parasite prevalence through microscopic observations. Amoebophrya sp. 1 infections were observed during both bloom events in August and October with relatively low parasite prevalence (0.1–1.5%), while Amoebophrya sp. 2 infections were detected only during the bloom event in October with high prevalence (up to 45%). Taken together, Amoebophrya sp. 1 may be a generalist and C. polykrikoides may not be its primary host, while Amoebophrya sp. 2 may be a specialist which can substantially impact host population dynamics.

Host Resistance, Genomics and Population Dynamics in a Salmonella Enteritidis and Phage System.

Bacteriophages represent an alternative solution to control bacterial infections. When interacting, bacteria and phage can evolve, and this relationship is described as antagonistic coevolution, a pattern that does not fit all models. In this work, the model consisted of a microcosm of Salmonella enterica serovar Enteritidis and φSan23 phage. Samples were taken for 12 days every 48 h. Bacteria and phage samples were collected; and isolated bacteria from each time point were challenged against phages from previous, contemporary, and subsequent time points. The phage plaque tests, with the genomics analyses, showed a mutational asymmetry dynamic in favor of the bacteria instead of antagonistic coevolution. This is important for future phage-therapy applications, so we decided to explore the population dynamics of Salmonella under different conditions: pressure of one phage, a combination of phages, and phages plus an antibiotic. The data from cultures with single and multiple phages, and antibiotics, were used to create a mathematical model exploring population and resistance dynamics of Salmonella under these treatments, suggesting a nonlethal, growth-inhibiting antibiotic may decrease resistance to phage-therapy cocktails. These data provide a deep insight into bacterial dynamics under different conditions and serve as additional criteria to select phages and antibiotics for phage-therapy.

Sediments from Arctic Tide-Water Glaciers Remove Coastal Marine Viruses and Delay Host Infection.

Over the past few decades, the Arctic region has been strongly affected by global warming, leading to increased sea surface temperatures and melting of land and sea ice. Marine terminating (tide-water) glaciers are expected to show higher melting and calving rates, with an increase in the input of fine sediment particles in the coastal marine environment. We experimentally investigated whether marine viruses, which drive microbial interactions and biogeochemical cycling are removed from the water column through adsorption to glacier-delivered fine sediments. Ecologically relevant concentrations of 30, 100 and 200 mg·L−1 sediments were added to filtered lysates of 3 cultured algal viruses and to a natural marine bacterial virus community. Total virus removal increased with sediment concentration whereby the removal rate depended on the virus used (up to 88% for an Arctic algal virus), suggesting a different interaction strength with the sediment. Moreover, we observed that the adsorption of viruses to sediment is a reversible process, and that desorbed viruses are still able to infect their respective hosts. Nonetheless, the addition of sediment to infection experiments with the Arctic prasinovirus MpoV-45T substantially delayed host lysis and the production of progeny viruses. We demonstrate that glacier-derived fine sediments have the potency to alter virus availability and consequently, host population dynamics.

Decoupling environmental effects and host population dynamics for anthrax, a classic reservoir-driven disease.

Quantitative models describing environmentally-mediated disease transmission rarely focus on the independent contribution of recruitment and the environment on the force of infection driving outbreaks. In this study we attempt to investigate the interaction between external factors and host’s population dynamics in determining the outbreaks of some indirectly transmitted diseases. We first built deterministic and stochastic compartmental models based on anthrax which were parameterized using information from literature and complemented with field observations. Our force of infection function was derived modeling the number of successful transmission encounters as a pure birth process that depends on the pathogen’s dispersion effort. After accounting for individual heterogeneity in pathogen’s dispersion effort, we allowed the force of infection to vary seasonally according to external factors recreating a scenario in which disease transmission increases in response to an environmental variable. Using simulations we demonstrate that anthrax disease dynamics in mid-latitude grasslands is decoupled from hosts population dynamics. When seasonal forcing was ignored, outbreaks matched hosts reproductive events, a scenario that is not realistic in nature. Instead, when allowing the force of infection to vary seasonally, outbreaks were only present in years were environmental variables were appropriate for the outbreaks to develop. We used the stochastic formulation of the force of infection to derive R0 under scenarios with different assumptions. The derivation of R0 allowed us to conclude that during epizootic years, pathogen contribution to disease persistence is nearly independent of dispersion. In endemic years, only pathogens with high dispersion significantly prevent disease extinction. Finally, we used our model in a maximum likelihood framework to estimate the parameters that determined a significant anthrax outbreak in Montana in 2008. Our study highlights the importance of the environment in determining anthrax outbreak intensity and could be useful to predict future events that could result in significant wildlife and domestic livestock losses.

Parasite in peril? A new species of mite in the genus Ophiomegistus Banks (Parasitiformes: Paramegistidae) on an endangered host, the pygmy bluetongue lizard Tiliqua adelaidensis (Peters) (Squamata: Scincidae)

AbstractHost‐parasite relationships are generally understudied in wild populations but have a potential to influence host population dynamics and the broader ecosystem, which becomes particularly important when the host is endangered. Herein we describe a new species of parasitic mite from the genus Ophiomegistus (Parasitiformes: Mesostigmata: Paramegistidae) of an endangered South Australian skink; the pygmy bluetongue lizard (Tiliqua adelaidensis). Adult mites were observed on lizard hosts in three different host populations, among which prevalence varied. No temporal trend in prevalence was evident over two spring‐summer seasons of monitoring. We hypothesise that the reliance on burrows as refuges by T. adelaidensis may be essential for the completion of the mite life cycle and also for horizontal transmission. The conservation implications of not only its effect on the host, but also its potential status as an endangered species itself, are considered.

Tick parasitism in the Mediterranean spur-thighed tortoise in the Maamora forest, Morocco

Macroparasites in general, and ectoparasites in particular, have the potential to regulate host population dynamics. In this context, this study addresses the tick parasitism traits of the Mediterranean spur-thighed tortoise (Testudo graeca) in the core area of its distribution range (northwestern Morocco, Maamora). It was discovered that 92.5% of the tortoises were parasitized by ticks in spring, with an infestation intensity and an abundance of 6.7 and 6.2 tick/tortoise, respectively. The observed parasitization rates were among the highest reported worldwide for T. graeca, which could relate to density-depended effects driving host-parasite interactions. The main tick species that parasitized the tortoises were Hyalomma aegyptium (95.6% of the ticks and in the 100% of the parasitized tortoises), Hy. marginatum, Hy. excavatum and Hy. scupense. Individual predictors for the tortoises, such as age, sex and the interaction between body condition and sex, were significantly related to tick abundance. Age-related behavioural differences might favour a higher host-tick effective contact in adults than in juveniles. The fact that males are more active in spring - the breeding season - might explain the observed male-bias in tick abundance and may also be responsible for the negative effect of male body condition on tick infestation rate in contrast to females. Given the potential role played by parasites as regards modulating population dynamics, our results suggest that ticks should be taken into account in the conservation and management programmes of this tortoise species.

Disease and climate effects on individuals drive post‐reintroduction population dynamics of an endangered amphibian

AbstractThe emergence of novel pathogens often has dramatic negative effects on previously unexposed host populations. Subsequent disease can drive populations and even species to extinction. After establishment in populations, pathogens can continue to affect host dynamics, influencing the success or failure of species recovery efforts. However, quantifying the effect of pathogens on host populations in the wild is challenging because individual hosts and their pathogens are difficult to observe. Here, we use long‐term mark–recapture data to describe the dynamics of reintroduced populations of an endangered amphibian (Rana sierrae) and evaluate the success of these recovery efforts in the presence of a recently emerged pathogen, the amphibian chytrid fungus Batrachochytrium dendrobatidis. We find that high B. dendrobatidis infection intensities are associated with increases in frog detectability and reductions in survival. When average infection intensities are high, adults are more likely to gain infections and less likely to lose infections. We also find evidence for intensity‐dependent survival, with heavily infected individuals suffering higher mortality. These results highlight the need in disease ecology for probabilistic approaches that account for uncertainty in infection intensity using imperfect observational data. Such approaches can advance the understanding of disease impacts on host population dynamics, and in the current study will improve the effectiveness of species conservation actions.

Parasite and host biomass and reproductive output in barnacle populations in the rocky intertidal zone.

The rocky intertidal zone has a long history of ecological study with barnacles frequently serving as a model system to explore foundational theories. Parasites are often ignored in community ecology studies, and this particularly holds for true for the rocky intertidal zone. We explore the role of the isopod parasite, Hemioniscus balani, on its host, the acorn barnacle, Chthamalus fissus. We use the currencies of biomass and reproduction measured at the individual level, then applied to the population level, to evaluate the importance of this parasite to barnacle populations. We found H. balani can comprise substantial biomass in 'apparent' barnacle populations, sometimes even equaling barnacle biomass. Additionally, parasite reproduction sometimes matched barnacle reproduction. Thus, parasites divert substantial energy flow from the barnacle population and to near-shore communities in the form of parasite larvae. Parasites appeared to decrease barnacle reproduction per area. Potentially, this parasite may control barnacle populations, depending on the extent to which heavily infected barnacle populations contribute to barnacle populations at larger scales. These findings regarding the importance of a particular parasite for host population dynamics in this well studied ecosystem call for the integration of disease dynamics into community ecological studies of the rocky intertidal zone.

Broad, Multi-Year Sampling Effort Highlights Complex Dynamics of the Tick-Borne PathogenEhrlichia chaffeensis(Rickettsiales: Anaplasmatacae)

Ehrlichia chaffeensis (Rickettsiales: Anaplasmatacae), an understudied bacterial pathogen emerging in the eastern United States, is increasing throughout the range of its vector, the lone star tick [Amblyomma americanum, L. (Acari: Ixodidae)]. To mitigate human disease risk, we must understand what factors drive E. chaffeensis prevalence. Here, we report patterns of E. chaffeensis prevalence in southeastern Virginia across 4 yr and ask how seasonal weather patterns affect variation in rates of E. chaffeensis occurrence. We collected A. americanum nymphs at 130 plots across southeastern Virginia in 2012, 2013, 2015, and 2016, and used polymerase chain reaction and gel electrophoresis to test for the presence of E. chaffeensis DNA. Prevalence estimates varied among years, ranging from 0.9% to 3.7%, and persistence of E. chaffeensis occurrence varied across space, with some sites never testing positive, and one site testing positive every year. Using generalized linear mixed-effects models, we related E. chaffeensis occurrence to temperature, humidity, vapor-pressure deficit, and precipitation during seasons up to 21 mo prior to sampling. Surprisingly, all support was lent to a positive effect of temperature during the previous fall and winter (i.e., prior to the nymphs' hatching), which we hypothesize to influence reservoir host population dynamics through changes to mortality or natality. Although further work is necessary to truly elucidate the mechanisms at play, our study shows E. chaffeensis distribution to be very dynamic across multiple dimensions, demanding broad concerted monitoring efforts that can consider both space and time.

An Operational System for Surveillance and Ecological Forecasting of West Nile Virus Outbreaks

Mosquito-borne disease surveillance has traditionally focused on tracking human cases along with the abundance and infection status of mosquito vectors. Vector and host population dynamics are also sensitive to climatic factors, including temperature fluctuations and the availability of surface water for mosquito breeding. There is a potential to strengthen surveillance and predict future outbreaks by monitoring environmental risk factors using broad-scale sensor networks that include earth-observing satellites. The South Dakota Mosquito Information System (SDMIS) project combines entomological surveillance with gridded meteorological data from NASA’s North American Land Data Assimilation System (NLDAS) to generate weekly risk maps for West Nile virus (WNV) in the north-central United States. Critical components include a mosquito infection model that smooths the noisy infection rate and compensates for unbalanced sampling, and a human infection model that combines entomological risk estimates with lagged effects of meteorological variables from the North American Land Data Assimilation System (NLDAS). Two types of forecasts are generated: long-term forecasts of statewide risk extending through the entire WNV season, and short-term forecasts of the geographic pattern of WNV risk in the upcoming week. Model forecasts are connected to public health actions through decision support matrices that link predicted risk levels to a set of phased responses. SDMIS accurately predicted higher-than-normal WNV transmission in 2016 and lower-than-normal transmission in 2017. Our experiences highlight several important lessons that can inform future efforts at disease early warning. These include the value of integrating climatic models with recent observations of infection, the importance of automated workflows to facilitate timely integration of multiple data streams, and the need to link forecasts with specific public health responses.

Pneumococcal Vaccines: Host Interactions, Population Dynamics, and Design Principles.

Streptococcus pneumoniae (the pneumococcus) is a nasopharyngeal commensal and respiratory pathogen. Most isolates express a capsule, the species-wide diversity of which has been immunologically classified into ∼100 serotypes. Capsule polysaccharides have been combined into multivalent vaccines widely used in adults, but the T cell independence of the antibody response means they are not protective in infants. Polysaccharide conjugate vaccines (PCVs) trigger a T cell-dependent response through attaching a carrier protein to capsular polysaccharides. The immune response stimulated by PCVs in infants inhibits carriage of vaccine serotypes (VTs), resulting in population-wide herd immunity. These were replaced in carriage by non-VTs. Nevertheless, PCVs drove reductions in infant pneumococcal disease, due to the lower mean invasiveness of the postvaccination bacterial population; age-varying serotype invasiveness resulted in a smaller reduction in adult disease. Alternative vaccines being tested in trials are designed to provide species-wide protection through stimulating innate and cellular immune responses, alongside antibodies to conserved antigens.

Regeneration for resilience framework to support regeneration decisions for species with populations at risk of extirpation by white pine blister rust

Natural forests are increasingly invaded by nonnative pests and pathogens that threaten host species with population extirpation and cascading ecological impacts. The regeneration for resilience (R4R) framework provides a decision structure to prioritize limited resources and utilize artificial and natural regeneration management to offer the best likelihood of success in positioning stands and landscapes to support multi-generational self-sustaining host populations in the presence of the nonnative invader by (1) increasing host population size to offset invader-caused mortality, (2) increasing the frequency of genetic resistance traits in host populations in habitats that enable their expression and durability to retard future mortality and facilitate population sustainability and recovery, and (3) maintain host genetic diversity, adaptive capacity, and population connectivity. This application is designed for conditions where the nonnative invader is expected to be a persistent threat, the host species naturally has some genetic resistance to the invasive species, and the forest host populations are integral to support valued ecosystem processes and services. The R4R framework has been developed for application in high elevation five-needle pine ecosystems of North America impacted and threatened by the nonnative pathogen Cronartium ribicola that causes the lethal disease white pine blister rust (WPBR). Several examples using the R4R framework to integrate information on current forest condition, WPBR risk or hazard, genetic resistance to WPBR, and host population dynamics and silvics to prioritize areas and design interventions are discussed. Effective management of forest regeneration dynamics can increase forest resilience and adaptive capacity to mitigate impacts of invasive species.

Pathogens in space: Advancing understanding of pathogen dynamics and disease ecology through landscape genetics.

Landscape genetics has provided many insights into how heterogeneous landscape features drive processes influencing spatial genetic variation in free‐living organisms. This rapidly developing field has focused heavily on vertebrates, and expansion of this scope to the study of infectious diseases holds great potential for landscape geneticists and disease ecologists alike. The potential application of landscape genetics to infectious agents has garnered attention at formative stages in the development of landscape genetics, but systematic examination is lacking. We comprehensively review how landscape genetics is being used to better understand pathogen dynamics. We characterize the field and evaluate the types of questions addressed, approaches used and systems studied. We also review the now established landscape genetic methods and their realized and potential applications to disease ecology. Lastly, we identify emerging frontiers in the landscape genetic study of infectious agents, including recent phylogeographic approaches and frameworks for studying complex multihost and host‐vector systems. Our review emphasizes the expanding utility of landscape genetic methods available for elucidating key pathogen dynamics (particularly transmission and spread) and also how landscape genetic studies of pathogens can provide insight into host population dynamics. Through this review, we convey how increasing awareness of the complementarity of landscape genetics and disease ecology among practitioners of each field promises to drive important cross‐disciplinary advances.