Wildlife Disease Research Articles

Transmissible cancer influences immune gene expression in an endangered marsupial, the Tasmanian devil (Sarcophilus harrisii).

Understanding the effects of wildlife diseases on populations requires insight into local environmental conditions, host defence mechanisms, host life‐history trade‐offs, pathogen population dynamics, and their interactions. The survival of Tasmanian devils (Sarcophilus harrisii) is challenged by a novel, fitness limiting pathogen, Tasmanian devil facial tumour disease (DFTD), a clonally transmissible, contagious cancer. In order to understand the devils’ capacity to respond to DFTD, it is crucial to gain information on factors influencing the devils’ immune system. By using RT‐qPCR, we investigated how DFTD infection in association with intrinsic (sex and age) and environmental (season) factors influences the expression of 10 immune genes in Tasmanian devil blood. Our study showed that the expression of immune genes (both innate and adaptive) differed across seasons, a pattern that was altered when infected with DFTD. The expression of immunogbulins IgE and IgM:IgG showed downregulation in colder months in DFTD infected animals. We also observed strong positive association between the expression of an innate immune gene, CD16, and DFTD infection. Our results demonstrate that sampling across seasons, age groups and environmental conditions are beneficial when deciphering the complex ecoevolutionary interactions of not only conventional host‐parasite systems, but also of host and diseases with high mortality rates, such as transmissible cancers.

Endemic Lineages of Batrachochytrium dendrobatidis Are Associated With Reduced Chytridiomycosis-Induced Mortality in Amphibians: Evidence From a Meta-Analysis of Experimental Infection Studies.

Emerging infectious wildlife diseases have caused devastating declines, particularly when pathogens have been introduced in naïve host populations. The outcome of disease emergence in any host population will be dictated by a series of factors including pathogen virulence, host susceptibility, and prior opportunity for coevolution between hosts and pathogens. Historical coevolution can lead to increased resistance in hosts and/or reduced virulence in endemic pathogens that allows stable persistence of host and pathogen populations. Adaptive coevolution may also occur on relatively short time scales following introduction of a novel pathogen. Here, we performed a meta-analysis of multi-strain Batrachochytrium dendrobatidis (Bd) infection experiments to test whether: (1) amphibian hosts exhibit lower mortality rates when infected with strains belonging to endemic Bd lineages relative to the Global Panzootic Lineage (Bd-GPL), hypothetically owing to long co-evolutionary histories between endemic Bd lineages and their amphibian hosts; and (2) amphibians exhibit lower mortality rates when infected with local Bd-GPL strains compared with non-local Bd-GPL strains, hypothetically owing to recent selection for tolerance or resistance to local Bd-GPL strains. We found that in a majority of cases, amphibians in endemic Bd treatments experienced reduced mortality relative to those in Bd-GPL treatments. Hosts presumed to have historically coexisted with endemic Bd did not show reduced mortality to Bd-GPL compared with hosts that have not historically coexisted with endemic Bd. Finally, we detected no overall difference in amphibian mortality between local and non-local Bd-GPL treatments. Taken together, our results suggest that long-term historical coexistence is associated with less disease-induced mortality potentially due to hypovirulence in endemic Bd lineages, and that more recent coexistence between amphibians and Bd-GPL has not yet resulted in reduced host susceptibility or pathogen virulence. This corroborates previous findings that Bd-GPL introduced via the global amphibian trade has a high capacity for causing disease-induced mortality.

Emerging infectious disease triggered a trophic cascade and enhanced recruitment of a masting tree.

There are several mechanisms that allow plants to temporarily escape from top-down control. One of them is trophic cascades triggered by top predators or pathogens. Another is satiation of consumers by mast seeding. These two mechanisms have traditionally been studied in separation. However, their combined action may have a greater effect on plant release than either process alone. In 2015, an outbreak of a disease (African swine fever, ASF) caused a crash in wild boar (Sus scrofa) abundance in Białowieża Primeval Forest. Wild boar are important consumers of acorns and are difficult to satiate relative to less mobile granivores. We hypothesized that the joint action of the ASF outbreak and masting would enhance regeneration of oaks (Quercus robur). Data from ungulate exclosures demonstrated that ASF led to reduction in acorn predation. Tree seedling data indicated that oak recruitment increased twofold relative to pre-epidemic period. Our results showed that perturbations caused by wildlife disease travel through food webs and influence forest dynamics. The outbreak of ASF acted synergistically with masting and removed herbivore top-down control of oaks by mobile consumers. This illustrates that the ASF epidemic that currently occurs across Europe can have broad effects on forest dynamics.

Sick of attention: The effect of a stress‐related disease on juvenile green sea turtle behaviour in the face of intense and prolonged tourism

Abstract Anthropogenic activities are increasingly linked to emerging diseases that cause mortality across many taxa. Human interference arising from ecotourism, in particular, can increase the stress levels of wild populations and promote the spread of disease. In Akumal Bay, Mexico, green sea turtles (Chelonia mydas) are increasingly infected with fibropapillomatosis (FP), an infectious disease associated with stress‐induced immunosuppression linked to high human density, which is particularly high in this area because of the increasing number of tourists visiting all year round. To examine whether FP might be associated with behavioural indicators of stress and varying levels of tourist pressure, the behaviour of turtles and the number of tourists were observed through 20‐minute focal sampling periods from May to August 2017. Disease presence and tourist pressure were related to several aspects of turtle behaviour, specifically feeding, resting, vertical movements (i.e. surfacing and diving), and evasive responses. Turtles that had visible FP engaged in fewer feeding periods, vertical movements, and evasive responses. Additionally, with increasing tourist pressure, all turtles spent less time engaging in vertical movements and had more evasive responses. These results suggest that the presence of FP affects green sea turtle behaviour, potentially increasing their exposure to tourists. Sick and healthy turtles appear to react differently to tourists, suggesting that FP changes behavioural responses to tourist pressure. Future management strategies should consider regulating tourist pressure on sick animals to reduce the incidence and progression of FP and other wildlife diseases by limiting access to critical habitats and enforcing code‐of‐conduct compliance from visiting tourists.

Combining seroprevalence and capture-mark-recapture data to estimate the force of infection of brucellosis in a managed population of Alpine ibex

In wildlife, epidemiological data are often collected using cross-sectional surveys and antibody tests, and seroprevalence is the most common measure used to monitor the transmission dynamics of infectious diseases. On the contrary, the force of infection, a measure of transmission intensity that can help understand epidemiological dynamics and monitor management interventions, remains rarely used. The force of infection can be derived from age-stratified cross-sectional serological data, or from longitudinal data (although less frequently available in wildlife populations). Here, we combined seroprevalence and capture-mark-recapture data to estimate the force of infection of brucellosis in an Alpine ibex (Capra ibex) population monitored from 2012 to 2018. Because the seroprevalence of brucellosis was 38% in this population in 2012, managers conducted two culling operations in 2013 and 2015, as well as captures every year since 2012, where seronegative individuals were marked and released, and seropositive individuals were removed. We obtained two estimates of the force of infection and its changes across time, by fitting (i) a catalytic model to age-seroprevalence data obtained from unmarked animals (cross-sectional), and (ii) a survival model to event time data obtained from recaptures of marked animals (longitudinal). Using both types of data allowed us to make robust inference about the temporal dynamics of the force of infection: indeed, there was evidence for a decrease in the force of infection between mid-2014 and late 2015 in both datasets. The force of infection was estimated to be reduced from 0.115 year-1 [0.074–0.160] to 0.016 year-1 [0.001–0.057]. These results confirm that transmission intensity decreased during the study period, probably due to management interventions and natural changes in infection dynamics. Estimating the force of infection could therefore be a valuable complement to classical seroprevalence analyses to monitor the dynamics of wildlife diseases, especially in the context of ongoing disease management interventions.

First isolation of Trichuris from Chinese serow, Capricornis milneedwardsii (Cetartiodactyla: Caprinae).

Whipworms are soil-transmitted helminths that can infect a variety of animals. A Chinese serow possibly infected by whipworms was found during a wildlife disease surveillance project in Baima Snow Mountain National Nature Reserve, Yunnan, China, in 2021. As convergent evolution is common in coinhabiting parasites, a mitochondrial gene sequence (cox1) and ribosomal gene sequence (ITS1) were used to identify species similar to Trichuris from Chinese serow. The phylogenetic trees and genetic distances of ten Trichuris samples from a Chinese serow together with other Trichuris spp. that have been previously reported were analysed based on the cox1 and ITS1 sequences. The combined results of the phylogenetic tree and genetic distances based on cox1 gene showed that the whipworms in Chinese serow are T. skrjabini. However, the whipworms in the present study were divided into two apparent clades in the phylogenic trees constructed by the cox1 sequences (Clades A and B) and the ITS1 sequences (Clades C and D). In addition, the Fst and Nm values were 0.82 and 0.23 between Clade A and Clade B for the cox1 gene, and 0.30 and 0.45 between Clade C and Clade D for the ITS1 sequences; both indicators showed low gene flow among the clades. Therefore, the genetic population structure of T. skrjabini was illustrated.

Update on the development of an app (adaptation of iMammalia) for early reporting of wild boar carcasses by a warning system

Citizen science (CS) has been increasingly used in wildlife disease surveillance since it can facilitate the detection and recovery of carcasses of target species used as sentinels of infection. This report updates on the improvement of an app adapted from iMammalia (MammalNet project) for early reporting carcasses of wild boar with a warning system. This app has a great potential for improving wildlife disease surveillance (carcass reporting), such as for ASF. The app has been expanded in the context of ENETWILD project during the second part of 2021 to several countries in their respective languages: Italy, Greece, Serbia, Montenegro, Kosovo, Bosnia-Herzegovina, North Macedonia, Albania, and the latest to incorporate, Portugal. The ENETWILD project has generated alliance with FAO to promote the use of iMammalia in the Balkans to collect data in gap areas about the distribution of wild boar, to document the presence of carcasses of dead animals. The technical improvements that have been made to meet the needs of iMammalia to report the presence of wild boar carcasses correspond to the possibility of recording different parameters, such as sex, age, whether the dead animal has been hunted or not, or the degree of decomposition observed. The possibility of generating warnings to notify these records in real time to wildlife and/or sanitary services will be implemented in 2022. To date, iMammalia collected 14,393 mammal observations all over Europe, 797 of which corresponds to wild boar. A total of 1,270 observations correspond to animals found dead (5.53%), 30 out of which are wild boar, which, in some cases, were later diagnosed as ASF positive (e.g. in Serbia). We finally summarize the next step of ENETWILD in relation to iMammalia promotion, including an online workshop to provide an overview of disease surveillance systems in Europe, and to propose changes, including the promotion of CS.

Sensitivity of an international notification system for wildlife diseases: A case study using the OIE‐WAHIS data on tularemia

The World Organization for Animal Health (OIE) has recently developed a Wildlife Health Framework to respond to the need of members to manage the risk from emerging diseases at the animal–human–ecosystem interface. One of its objectives is to improve surveillance systems, early detection and notification of wildlife diseases. Members share information on disease occurrence by reporting through the OIE World Animal Health Information System (OIE‐WAHIS—formerly known as ‘WAHIS’). To evaluate the capacity of a surveillance system to detect disease events, it is important to quantify the gap between all known events and those officially notified to the OIE. This study used capture–recapture analysis to estimate the sensitivity of the OIE‐WAHIS system for a OIE‐listed wildlife disease by comparing information from publicly available sources to identify undetected events. This article presents a case study of the occurrence of tularemia in lagomorphs among selected North American and European countries during the period 2014–2019. First, an analysis using three data sources (OIE‐WAHIS, ProMED, WHO‐EIOS [Epidemic Intelligence from Open Sources]) was conducted. Subsequent analysis then explored the model integrating information from a fourth source (scientific literature collected in PubMed). Two models were built to evaluate both the sensitivity of the OIE‐WAHIS using media reports (ProMED and WHO‐EIOS), which is likely to represent current closer to real‐time events, and published scientific data, which is more useful for retrospective analysis. Using the three‐source approach, the predicted number of tularemia events was 93 (95% CI: 75–114), with an OIE‐WAHIS sensitivity of 90%. In the four‐source approach, the number of predicted events increased to 120 (95% CI: 99–143), dropping the sensitivity of the OIE‐WAHIS to 70%. The results indicate a good sensitivity of the OIE‐WAHIS system using the three‐source approach, but lower sensitivity when including information from the scientific literature. Further analysis should be undertaken to identify diseases and regions for which international reporting presents a low sensitivity. This will enable evaluation and prioritization of underreported OIE‐listed wildlife diseases and identify areas of focus as part of the Wildlife Health Framework. This study also highlights the need for stronger collaborations between academia and National Veterinary Services to enhance surveillance systems for notifiable diseases.

Development of Cathepsin L-like Real-Time PCR Assays for the Detection of African Animal Trypanosomosis (AAT) in South Africa.

African animal trypanosomosis (AAT), is an infectious parasitic disease of wildlife and livestock caused by multiple species and strains of Trypanosoma. In South Africa, it is restricted to northern KwaZulu-Natal (NKZN) and caused by Trypanosoma congolense and Trypanosoma vivax. A cross-sectional study was done to determine AAT prevalence in 384 goat samples and identify trypanosome species circulating in 60 cattle at dip tanks that are on the interface with the Hluhluwe-uMfolozi game reserve in NKZN. Both cattle and goat samples were analyzed using the buffy coat technique (BCT) and a polymerase chain reaction (PCR) assay targeting the internal transcribed spacer 1 (ITS) region. Cattle samples were further analyzed using an ITS quantitative real-time PCR (qPCR) assays designed for the detection of T. congolense, T. vivax, and T. brucei. None of the goat samples tested positive for Trypanosoma infections. The ITS qPCR assay detected Trypanosoma DNA in 30% of the cattle samples, while only 8.3% were positive with the ITS PCR and 11.7% were positive using BCT. Quantitative real-time PCR assays were designed to amplify a 98 bp, 137 bp, and 116 bp fragment of the cathepsin L-like (CATL) gene from T. brucei, T. theileri, and T. congolense, respectively. Each assay was shown to be efficient (>94%) and specific (109 to 102/101 copies/reaction) in the detection of Trypanosoma species. The CATL qPCR assays detected T. congolense and T. theileri infections in 33.3% of the cattle samples. The CATL qPCR assays also detected T. congolense infections in goats (23.1%) that were neither detected by BCT nor the ITS PCR. The CATL qPCR assays provide an additional, sensitive, and specific tool for Trypanosoma diagnostics. The presence of trypanosomes in goats suggests they might be potential reservoirs of infections to other livestock.

Experimental inoculation trial to determine the effects of temperature and humidity on White-nose Syndrome in hibernating bats

Disease results from interactions among the host, pathogen, and environment. Inoculation trials can quantify interactions among these players and explain aspects of disease ecology to inform management in variable and dynamic natural environments. White-nose Syndrome, a disease caused by the fungal pathogen, Pseudogymnoascus destructans (Pd), has caused severe population declines of several bat species in North America. We conducted the first experimental infection trial on the tri-colored bat, Perimyotis subflavus, to test the effect of temperature and humidity on disease severity. We also tested the effects of temperature and humidity on fungal growth and persistence on substrates. Unexpectedly, only 37% (35/95) of bats experimentally inoculated with Pd at the start of the experiment showed any infection response or disease symptoms after 83 days of captive hibernation. There was no evidence that temperature or humidity influenced infection response. Temperature had a strong effect on fungal growth on media plates, but the influence of humidity was more variable and uncertain. Designing laboratory studies to maximize research outcomes would be beneficial given the high costs of such efforts and potential for unexpected outcomes. Understanding the influence of microclimates on host–pathogen interactions remains an important consideration for managing wildlife diseases, particularly in variable environments.

Facts about Wildlife Diseases: SARS-CoV2 in white-tailed deer

SARS Cov2, the virus that causes COVID-19, has been discovered in white-tailed deer. This publication provides information to the general public, hunters, and deer farmers as to what SARS CoV2 is, the evidence for COVID-19 in deer, and if people can get COVID-19 from deer.

West Nile Virus Infections in an Urban Colony of American White Ibises (Eudocimus albus) in South Florida, USA.

West Nile virus (WNV) is pathogenic in a wide range of avian hosts and is endemic in much of North America. This virus is responsible for population declines of some Passeriformes. We describe a WNV-associated mortality event in American White Ibis (Eudocimus albus) nestlings. This is a species, inherent to the Everglades ecosystem, which has recently begun nesting in urban areas. An urban colony in south Florida was monitored from March-July in 2020 as part of an ongoing study. Nestling carcasses were collected opportunistically and sent to the Southeastern Cooperative Wildlife Disease Study, University of Georgia within 24 h for diagnosis. Three ibis nestling deaths were confirmed to be caused by WNV infection based on histopathology, immunohistochemistry, and reverse transcription PCR. Serial plasma samples collected weekly from 36 healthy chicks of the same urban rookery were tested for WNV-neutralizing antibodies via plaque reduction neutralization test; four chicks were seropositive. Antibody titers in three seropositive chicks from which serial samples were collected waned over time, suggesting maternal antibody transfer. Ibis mortalities were consistent with a spike of WNV activity in this region of Florida. West Nile virus infection may be an important seasonal cause of mortality for wading bird nestlings.

Leptospira Infection in Wild Animals.

Book reviews express the opinions of the individual authors regarding the value of the book's content for Journal of Wildlife Diseases readers. The reviews are subjective assessments and do not necessarily reflect the opinions of the editors, nor do they establish any official policy of the Wildlife Disease Association.

Using transcriptomics to predict and visualize disease status in bighorn sheep (Ovis canadensis).

Increasing risk of pathogen spillover coupled with overall declines in wildlife population abundance in the Anthropocene make infectious disease a relevant concern for species conservation worldwide. While emerging molecular tools could improve our diagnostic capabilities and give insight into mechanisms underlying wildlife disease risk, they have rarely been applied in practice. Here, employing a previously reported gene transcription panel of common immune markers to track physiological changes, we present a detailed analysis over the course of both acute and chronic infection in one wildlife species where disease plays a critical role in conservation, bighorn sheep (Ovis canadensis). Differential gene transcription patterns distinguished between infection statuses over the course of acute infection and differential correlation (DC) analyses identified clear changes in gene co-transcription patterns over the early stages of infection, with transcription of four genes-TGFb, AHR, IL1b and MX1-continuing to increase even as transcription of other immune-associated genes waned. In a separate analysis, we considered the capacity of the same gene transcription panel to aid in differentiating between chronically infected animals and animals in other disease states outside of acute disease events (an immediate priority for wildlife management in this system). We found that this transcription panel was capable of accurately identifying chronically infected animals in the test dataset, though additional data will be required to determine how far this ability extends. Taken together, our results showcase the successful proof of concept and breadth of potential utilities that gene transcription might provide to wildlife disease management, from direct insight into mechanisms associated with differential disease response to improved diagnostic capacity in the field.

Rift Valley fever virus: Movement of infected humans threatens global public health and agriculture

Abstract Rift Valley fever (RVF) is an acute disease of ungulate livestock and wildlife as well as humans caused by the Rift Valley fever virus (RVFV), which can be transmitted by arthropod vectors such as mosquitoes as well as by direct contact with infected tissues. Outbreaks of this virus may lead to widespread mortality and morbidity in susceptible ungulates and humans, with pronounced economic and agricultural impacts. Humans infected with RVFV can develop extremely high viremias capable of infecting vectors such as mosquitoes. Critically, RVFV has potential for globalization resulting from the movement of infected humans into non-endemic regions containing populations of potentially competent mosquito vectors and susceptible livestock and wildlife hosts that include the US, Asia, and parts of southern Europe. In this review, we explore scenarios of escape of RVFV from its endemic range that could be caused by the movement of infected humans. The risks of globalization of the RVFV pathogen into Europe, Asia, and the Americas is high and increasing each year because of climate change, redistribution and expanding ranges of vector and host species, lack of an approved human vaccine, insecticide resistance, and international travel and commerce. We discuss approaches that could be used to mitigate these avenues of spread that include surveillance targeted by environmental modeling coupled with decisive vector control.

Countermeasures for the development of Chinese wildlife disease surveillance and response system under One Health Framework

Countermeasures for the development of Chinese wildlife disease surveillance and response system under One Health Framework

Establishment of Disease Surveillance Systems in Rural Communities of Sierra Leone

Using the native intelligence of rural people to establish a surveillance system reduces morbidity, mortality, poverty, and zoonotic and neglected disease outbreaks among humans and animals. People in rural communities constantly interact with domestic and wildlife, placing them at high risk of exposure to diseases. Health personnel is unevenly distributed, with the majority in the capital cities, making rural communities lack professional health personnel and health care service providers. Poverty limited rural people’s access to health care facilities. Emerging disease outbreaks resulting from complicated environmental changes pose a fundamental challenge in low-income countries, impacting the foundation of human and animal health. People find it difficult to reach medical centers due to a lack of funds. The Animal Health Club engaged thirty (30) villages in a focus group discussion and in-depth interview. Animal Health Club used information obtained to develop a semistructured questionnaire (600) and observed the people during the talks. Community people identify nine sources of diseases, including humans, poultry, wildlife, pets, ruminants’ crops, water, toilets, and garbage dump. The people elected/selected an executive to organize and nominate people to surveillance the nine sources of diseases. Large villages were divided into zones, while smaller villages remain the same. The people identified ten domestic animals and twenty-four wildlife animals in their communities and some diseases associated with them. They also revealed a high level of interaction between domestic, wildlife, and humans in towns and bush in their respective communities. Rural people believed animals transfer diseases to humans in various ways. However, people contract diseases more from human-human interaction than human- animals interaction. The study’s main objective was to explore livestock and wildlife disease interface and transmission chains within the human population in the selected communities and establish community-level epidemiological surveillance systems to reduce disease incidence.

Bluetongue and epizootic haemorrhagic disease in wildlife with emphasis on the South American scenario

Bluetongue and epizootic hemorrhagic disease affect domestic ruminants and cervids. However, other species may act as pathogen carriers in the transition of bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV). The wild species affected by these diseases manifest a variable range of clinical signs and lesions, and while some species appear to be extremely susceptible, showing high levels of mortality, some are resistant to these pathogens, acting as potential reservoirs of these orbiviruses. The purpose of the following review is to describe the clinical and pathological manifestations related to these diseases in wild species and to review studies performed on non-domestic species in South America, emphasizing the challenges of studying infectious diseases in free-living animals and the gaps in knowledge about bluetongue and epizootic haemorrhagic disease epidemiology. These gaps should be filled by more studies on the range of species affected and the transmission mechanisms, including in domestic species.

Skin bacterial metacommunities of San Francisco Bay Area salamanders are structured by host genus and habitat quality.

Host-associated microbial communities can influence physiological processes of macroorganisms, including contributing to infectious disease resistance. For instance, some bacteria that live on amphibian skin produce antifungal compounds that inhibit two lethal fungal pathogens, Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Therefore, differences in microbiome composition among host species or populations within a species can contribute to variation in susceptibility to Bd/Bsal. This study applies 16S rRNA sequencing to characterize the skin bacterial microbiomes of three widespread terrestrial salamander genera native to the western United States. Using a metacommunity structure analysis, we identified dispersal barriers for these influential bacteria between salamander families and localities. We also analysed the effects of habitat characteristics such as percent natural cover and temperature seasonality on the microbiome. We found that certain environmental variables may influence the skin microbial communities of some salamander genera more strongly than others. Each salamander family had a somewhat distinct community of putative anti-Bd skin bacteria, suggesting that salamanders may select for a functional assembly of cutaneous symbionts that could differ in its ability to protect these amphibians from disease. Our observations raise the need to consider host identity and environmental heterogeneity during the selection of probiotics to treat wildlife diseases.

Modelling management strategies for chronic disease in wildlife: Predictions for the control of respiratory disease in bighorn sheep

Abstract Controlling persistent infectious disease in wildlife populations is an ongoing challenge for wildlife managers and conservationists worldwide, and chronic diseases in particular remain a pernicious problem. Here, we develop a dynamic pathogen transmission model capturing key features of Mycoplasma ovipneumoniae infection, a major cause of population declines in North American bighorn sheep Ovis canadensis. We explore the effects of model assumptions and parameter values on disease dynamics, including density‐ versus frequency‐dependent transmission, the inclusion of a carrier class versus a longer infectious period, host survival rates, disease‐induced mortality and recovery rates and the epidemic growth rate. Along the way, we estimate the basic reproductive ratio, R0, for M. ovipneumoniae in bighorn sheep to fall between approximately 1.36 and 1.74. We apply the model to compare efficacies across a suite of management actions following an epidemic, including test‐and‐remove, depopulation‐and‐reintroduction, range expansion, herd augmentation and density reduction. Our results suggest that test‐and‐remove, depopulation‐and‐reintroduction and range expansion could help persistently infected bighorn sheep herds recovery following an epidemic. By contrast, augmentation could lead to worse outcomes than those expected in the absence of management. Other management actions that improve host survival or reduce disease‐induced mortality are also likely to improve population size and persistence of chronically infected herds. Synthesis and applications. Dynamic transmission models like the one employed here offer a structured, logical approach for exploring hypotheses, planning field experiments and designing adaptive management. We find that management strategies that removed infected animals or isolated them within a structured metapopulation were most successful at facilitating herd recovery from a low‐prevalence, chronic pathogen. Ideally, models like ours should operate iteratively with field experiments to triangulate on better approaches for managing wildlife diseases.