Zoonotic & Wildlife Disease Risks

Agency, public and hunter perceptions of mange in black bears

Francisco, R., Pienaar, E.F., & Yabsley, M.J. (2025) Perspectives on wildlife agency mange management in black bears and other carnivores. Journal of Wildlife Management, e70140.

Abstract: Sarcoptic mange is an emerging parasitic disease affecting North American black bears (Ursus americanus) and has been increasingly reported since the early 1990s. As mange spreads into naive bear populations, wildlife managers face challenges related to surveillance, interagency coordination, and stakeholder expectations. In 2023, we surveyed 35 state and federal wildlife agency personnel and academic partners to assess management practices for mange, barriers to effective interventions, and how agencies engage with the public and key stakeholders. Respondents represented 17 states, 7 with and 10 without reports of sarcoptic mange in black bears, with over half (51.4%) working in their current institution for more than 10 years. Respondents generally agreed on dispatching severely affected wildlife (97.1%) and monitoring mild to moderate cases. Although respondents supported stakeholder and public reporting of mange cases (71.4%), they opposed stakeholder and public intervention in mange management (e.g., treatment, handling, relocation). Fewer than half of respondents (45.7%) indicated that mange reports are entered into a formal dataset, limiting long-term surveillance and decision-making. Our study highlights the need for a unified multi-state communication framework to increase public support for agency management actions, and the importance of implementing a centralized mange data repository to enhance long-term surveillance of mange and improve response efforts.

Preventing tick-borne diseases

Torres, P., Pienaar, E.F., Ritchie, M., Gabriel, M., & Yabsley, M. (2025). Native Americans’ knowledge, attitudes, and practices regarding ticks and tick-borne diseases in northern California. One Health, 20, 100976. 

Abstract: Reports of tick-borne diseases (TBDs) are increasing worldwide, particularly in North America where a diversity of endemic and exotic tick species and pathogens occur. Native American populations have unique outdoor cultural and occupational practices that may impact their exposure to ticks, yet this risk remains understudied in the context of TBDs. To address this gap, we examined knowledge, attitudes, and practices regarding ticks and TBDs among Native American communities in Humboldt County, California. We conducted semi-structured interviews with participants, who represented various tribes, at a cultural gathering. Cultural practices intertwined closely with outdoor activities (e.g., ceremonies, dances), potentially influencing local tick exposure patterns. Most research participants had been bitten by ticks and reported tick exposure by children and pets. Research participants demonstrated low knowledge about ticks and TBDs, as well as low levels of risk perceptions pertaining to TBDs. Research participants most commonly conducted tick checks after outdoor activity, wore long-sleeved clothing outdoors, and used homeopathic remedies or essential oils to prevent exposure to ticks and TBDs. Culturally appropriate outreach and education initiatives are needed to address TBD risk among Native American communities. Our study lays the groundwork for future research on the intersection of cultural practices and tick exposure, with implications for public health interventions that are tailored to the needs of indigenous populations.

Preventing pathogen transmission by herpetofauna

Pienaar E.F., Episcopio-Sturgeon D.J., & Steele Z.T. (2022) Investigating public support for biosecurity measures to mitigate pathogen transmission through the herpetological trade. PLoS ONE 17(1): e0262719.

Abstract: The expanding global trade in herpetofauna has contributed to new infectious disease dynamics and pathways that allow for the rapid spread of pathogens geographically. Improved biosecurity is needed to mitigate adverse biodiversity, economic and human health impacts associated with pathogen transmission through the herpetological trade. However, general lack of knowledge of the pathogen transmission risks associated with the global trade in herpetofauna and public opposition to biosecurity measures are critical obstacles to successfully preventing pathogen transmission. In 2019 we administered a survey to 2,007 members of the public in the United States of America to ascertain their support for interventions to prevent the spread of Batrachochytrium dendrobatidis (Bd), Batrachochytrium salamandrivorans (Bsal), ranaviruses, and Salmonella through the herpetological trade. We presented survey respondents with different potential hazards associated with pathogen transmission through this trade, namely ecological, economic, and human health impacts. We used structural equation models to determine how these different hazards and respondents’ characteristics influenced respondents’ support for quarantine and veterinary observation of herpetofauna imported into the United States, mandatory tests for diseases of concern, and best practices to reduce stress and improve the care of live herpetofauna during transport to the United States. Respondents’ values and their perceived susceptibility and sensitivity to different hazards associated with pathogen transmission were key determinants of their support for biosecurity. Respondents with strong biospheric and altruistic values demonstrated sensitivity to ecological and human health impacts associated with pathogen transmission, whereas respondents with strong egoistic values demonstrated sensitivity to economic impacts. Respondents had limited knowledge of Bd, Bsal or ranaviruses, the size of the herpetological trade, or how this trade may contribute to pathogen transmission. Improved outreach and education on pathogen transmission through the herpetological trade is required, but it is important that messages are tailored to people with different values to elicit their support for biosecurity.

Shapiro H.G., Ruder M.G., Nimlos N.M., & Pienaar E.F. (2023) Understanding rabbit owners’ willingness to engage in disease prevention behaviors. Preventive Veterinary Medicine, 219: 106018.

Abstract: Rabbit hemorrhagic disease virus 2 (RHDV2) is a fatal, highly contagious pathogen that infects wild and domestic lagomorphs (rabbits and hares). RHDV2 is an important cause of disease in pet and companion rabbits, has resulted in economic losses for the commercial rabbit industry, and has caused declines of wild lagomorph populations. It is essential for domestic rabbit owners to engage in appropriate actions (e.g., using effective disinfectants, creating secure barriers between domestic and wild rabbits) to protect the health and welfare of their rabbits and reduce the risk of human-mediated spread of RHDV2. Thus, we investigated rabbit owners’ stated willingness to engage in nine commonly recommended biosecurity practices and their support for seven potential government-implemented management actions. We administered an online survey to 1790 rabbit owners in the United States between April and August 2021. Respondents were likely to engage in all biosecurity measures and were supportive of most management actions that could be implemented by government agencies. Respondents’ willingness to engage in and support biosecurity measures was positively correlated with their perceptions of the importance of biosecurity, risk perceptions pertaining to the impact of RHDV2 on lagomorphs and rabbit-related industries, knowledge of RHDV2, and trust in government to manage RHDV2. Respondents’ motivations for owning rabbits, husbandry behaviors, and demographic characteristics also influenced their willingness to engage in or support biosecurity measures. Engaging domestic rabbit owners in collaborative biosecurity measures is critical for protecting domestic rabbit health and preventing potential spillover between domestic and free-roaming lagomorphs, as there are still many uncertainties about how RHDV2 is spreading across the United States and the world. Implementing outreach strategies that communicate the importance and effectiveness of biosecurity practices in protecting rabbit welfare, rabbit-related activities, and wild lagomorph populations may increase the likelihood of rabbit owners adopting biosecurity measures.

Shapiro H.G., & Pienaar E.F. (2023) Falconer perceptions of, and support for, rabbit hemorrhagic disease biosecurity actions. Human-Wildlife Interactions 17(3): 342-360.

Abstract: Rabbit hemorrhagic disease virus 2 (RHDV2) is a highly contagious virus that primarily infects wild and domestic rabbits and hares (lagomorphs). In the United States (US), state wildlife agencies rely on stakeholders to report RHDV2-related mortalities and engage in voluntary biosecurity actions to prevent the spread of RHDV2. However, stakeholder perceptions of RHDV2 and relevant biosecurity actions have not been evaluated. We conducted the first study in the US on how falconers’ risk perceptions, knowledge, trust in state wildlife agencies to manage RHDV2, hunting behaviors, and demographic characteristics influenced their willingness to engage in voluntary biosecurity actions and support potential government-mandated biosecurity measures.  To complete our study, we surveyed 480 falconers in 45 states using an online questionnaire from April 2021 – March 2022. Most respondents were aware of RHDV2 but did not know about the multiple vectors for RHDV2 transmission or that infected lagomorphs are unlikely to show signs of disease. Most respondents were willing to engage in all voluntary biosecurity actions (52.9%-89.8%) and supported three of the four RHDV2 management strategies (56.0%-62.5%). Respondents’ willingness to engage in or support biosecurity measures depended on the importance they placed on biosecurity, their risk perceptions, and their trust in state wildlife agencies to manage RHDV2. Consistent, up to date outreach efforts should communicate the economic and hunting risks associated with RHDV2 and how falconer adoption of biosecurity behaviors may lower the risk of human-mediated RHDV2 spread. State wildlife agencies may build trust with falconry groups by actively engaging falconers in lagomorph and RHDV2 monitoring efforts and working with falconers to implement biosecurity measures that are safe for raptors while also lowering the risk of human-mediated RHDV2 spread.

Shapiro H.G., D'Angelo G., Ruder M.G., & Pienaar E.F. (2023) Engaging stakeholders in wildlife disease management: Hunters’ willingness to adopt and support biosecurity actions to prevent the spread of rabbit hemorrhagic disease. Conservation Science and Practice 5(1): e12858.

Abstract: Rabbit hemorrhagic disease virus 2 (RHDV2) is a highly contagious virus that primarily infects rabbits and hares (lagomorphs) and poses a serious threat to lagomorph populations and hunting. Wildlife agencies in the United States rely on hunters to report RHDV2-related mortalities and engage in voluntary biosecurity actions to prevent the spread of RHDV2. From April 2021 to April 2022, we conducted a nationwide survey of 22,511 hunters to ascertain their willingness to engage in voluntary biosecurity actions and support government-mandated biosecurity measures. Respondents expressed greatest willingness to report suspicious lagomorph deaths to wildlife agencies. Respondents’ willingness to engage or support biosecurity actions was positively correlated with their risk perceptions pertaining to lagomorph deaths and the economic impacts of RHDV2, perceptions of the importance of biosecurity, and trust in state agencies to manage RHDV2. We found evidence that respondents’ willingness to engage in or support biosecurity actions was also positively correlated with their knowledge of RHDV2. Wildlife agencies should clearly communicate about RHDV2 and its adverse impacts on lagomorphs, biodiversity, and hunting to engage hunters in biosecurity measures. Hunters can provide valuable information about lagomorph population trends and mortality events in the areas they hunt, a cost-effective method to augment agency surveillance.

Shapiro H.G., Ruder M.G., & Pienaar E.F. (2022) Down the rabbit hole: Domestic rabbit owners’ perceptions of rabbit hemorrhagic disease virus 2. EcoHealth 19: 487–501.

Abstract: Rabbit hemorrhagic disease virus 2 (RHDV2) is a highly contagious pathogen that infects wild and domestic rabbits and hares (lagomorphs). Globally, RHDV2 has resulted in substantial economic losses for commercial rabbit trade and caused wild lagomorph population declines. Previous research on RHDV2 suggests that human-mediated movement of rabbits may contribute to the spread of RHDV2. We conducted the first survey of individuals who own or interact with domestic rabbits to identify their rabbit husbandry behaviors and knowledge of, and concerns about, RHDV2. In 2021, we surveyed 1,807 rabbit owners, breeders, and rescue staff in the United States. Respondents had a high level of knowledge about RHDV2. Respondents believed RHDV2 posed a high risk to rabbit-related activities and were concerned about its economic and ecological impacts. Nearly half of respondents kept their rabbits indoors, but 10.7% of respondents allowed their rabbits outside frequently on properties used by wild lagomorphs. Respondents with five rabbits or less were generally willing to vaccinate their rabbits, but respondents with larger herds argued that vaccines were cost prohibitive. Given respondents’ concerns about RHDV2, communication about disease prevention should highlight the adverse ecological and economic consequences of RHDV2.

Shapiro H.G., Pienaar E.F., & Kohl M.T. (2022) Barriers to management of a foreign animal disease at the wildlife-domestic animal interface: The case of rabbit hemorrhagic disease in the United States. Frontiers in Conservation Science 3: 857678.

Abstract: The increasing global emergence of pathogens transmitted between wildlife and domestic animals are critically important conservation and economic concerns. International organizations, such as the World Organization for Animal Health (OIE), have called for cross-jurisdictional government investment in defensible, reliable surveillance systems and biosecurity measures to prevent pathogen transmission at the wildlife-domestic animal interface. A classic example of a pathogen that transmits across the wildlife-domestic animal interface is rabbit hemorrhagic disease virus 2 (RHDV2), which has spread to five continents in the 11 years since its discovery. RHDV2 is a highly contagious virus that infects wild and domestic rabbits and hares (lagomorphs). Globally, RHDV2 has resulted in population declines of wild lagomorphs, with associated biodiversity and hunting impacts, as well as economic losses for commercial rabbit industries. To assess the degree to which government agencies are positioned to engage in cross-jurisdictional approaches to mitigate pathogen spillover, we conducted the first study of how agricultural and wildlife agencies in the United States of America (U.S.) have responded to RHDV2 since it was detected in wild and domestic lagomorphs in March 2020. We surveyed and interviewed animal health personnel at 95 state wildlife and agricultural agencies, thereby accounting for all 50 states. Agencies have primarily responded to RHDV2 through disease investigations of potential RHDV2 cases, vaccinations, and education and outreach with the public and stakeholder groups. However, agencies' inconsistent jurisdiction within and across states over lagomorph populations and industries, limited knowledge of wild lagomorph populations and the composition of the domestic rabbit industry, and resource constraints have hindered management efforts. Improved understanding of the domestic lagomorph trade and transport routes is urgently needed to mitigate the risks associated with human-mediated movement of rabbits and RHDV2 across the U.S. Greater flexibility in agency funding and increased allocation of discretionary funds to agencies for management of animal diseases would allow agencies to respond more rapidly and effectively to emerging pathogens such as RHDV2. Federal leadership is needed to engage state agencies in collaborative, proactive interagency disease management across the U.S.

Presentations

Shapiro, H.R (Presenter), M.G. Ruder, G. D’Angelo, M.T. Kohl, and E.F. Pienaar “'Understanding Agency Response to and Hunters’ Perceptions of RHDV2” 71st Annual International Conference of the Wildlife Disease Association, Athens, Georgia, 29 July - 4 August 2023.

Pienaar, E.F., H. Shapiro (Presenter) and M.T. Kohl "Government response to RHDV2 at the wildlife-domestic animal interface in the United States." World Lagomorph Conference, Montpellier, France, 4-8 July 2022.

Shapiro, H. (Presenter) and E.F. Pienaar "Falconer support for interventions to mitigate the spread of rabbit hemorrhagic disease virus 2 (RHDV2) across the United States." World Lagomorph Conference, Montpellier, France, 4-8 July 2022.

Ruder, M.G., H. Shapiro (Presenter) and E.F. Pienaar "Understanding U.S. Rabbit Owners' Willingness to Engage in Biosecurity Measures to Prevent Transmission of RHDV2." World Lagomorph Conference, Montpellier, France, 4-8 July 2022.

Pienaar, E.F. (Presenter) and H. Shapiro "Understanding Stakeholder Perspectives on Rabbit Hemorrhagic Disease Management." Pathways: Human Dimensions of Wildlife Conference, Bremerton, Washington, May 2022.

Shapiro, H., E.F. Pienaar (Presenter), G. D'Angelo, M.T. Kohl and M.G. Ruder "'Rabbit Hemorrhagic Disease Management Across the U.S." Pathways: Human Dimensions of Wildlife Conference, Bremerton, Washington, May 2022.

Shapiro, H. (Presenter), E.F. Pienaar, G. D’Angelo, M. Kohl and M. Ruder “Down the Rabbit Hole: Understanding Key Stakeholder Perspectives on Rabbit Hemorrhagic Disease Management” The Wildlife Society Annual Conference, Virtual, November 1-5, 2021

Shapiro, H. (Presenter), E.F. Pienaar, M.G. Ruder, M. Kohl and G. D’Angelo “Understanding Agency Response to and Stakeholder Perceptions of RHDV2” 125th Annual Meeting of the United States Animal Health Association, Virtual, October 13, 2021. (Invited)

Shapiro, H. (Presenter), E.F. Pienaar, M.G. Ruder, M. Kohl and G. D’Angelo “Understanding Agency Response to and Stakeholder Perceptions of RHDV2” 111th Annual Meeting for the Association of Fish & Wildlife Agencies, Virtual, September 8-10, 2021. (Invited)

Shapiro, H. (Presenter), E.F. Pienaar, M.G. Ruder, G. D’Angelo and M.T. Kohl “RHDV2 Management Across the U.S.” Southeast Wildlife Health Technical Group Meeting, Athens, Georgia, June 14, 2021.