Managing Zoonotic Disease in Wildlife Populations: Priorities and Pitfalls of the Human Connection
Todd K. Shury, Ryan K. Brook, and Pushpakumara D.B. Nihal
Livestock disease management and surveillance can be very challenging but are even more difficult in free-ranging wildlife, due to the disparate and often remote nature of wildlife populations (Miller et al., 2013; Silk et al., 2019). Wildlife are generally either highly valued components of society or considered pests which must be eradicated. They are often publicly owned, highly mobile, and do not respect regional or national borders. A One Health approach has been advocated as a viable tactic to deal with wildlife reservoirs of disease This approach argues for including human, animal, and environmental considerations in all social and ecological aspects of disease management, with the ultimate goal of improving or reducing threats through harm reduction (Miller and Olea-Popelka, 2013; Buttke et al., 2015). This is easier done in theory than in practice. There are few documented and evaluated examples where One Health has been successful in a wildlife context. An interdisciplinary One Health approach typically takes longer, is more costly, and more logistically challenging due to large numbers of stakeholders with conflicting values, which makes group decision-making more complex. We use two examples, one in Canada and the other in Sri Lanka, to highlight cross-cultural lessons learned and how critical it is to consider local socio-economic factors. We believe wildlife managers, conservationists, public and private landholders, and societies can apply these lessons for successful disease management.
BOVINE TUBERCULOSIS IN CANADA
Bovine tuberculosis (ТВ) is an insidious disease primarily of cattle, with the causative bacterium Mycobacterium bovis, having a substantial host range among many mammals, including humans. There are numerous wildlife reservoirs of ТВ worldwide which have complicated eradication or control efforts in South Africa, New Zealand, the United Kingdom, Spain, the United States, and Canada (Palmer, 2013). Canada has had a national ТВ eradication programme since 1923 and has been considered free of bovine ТВ in its cattle herd since 1985 (Wobeser, 2009). Following the first bovine ТВ-positive wild elk (Cervus canadensis) in the area around Riding Mountain National Park in 1992 in the province of Manitoba (Lees, 2004), a Manitoba Bovine Tuberculosis Task Force was created to help manage the disease in wildlife and cattle. The task force comprised four government agencies: two involving wildlife (Manitoba Sustainable Development, and the Parks Canada Agency), and two involving agriculture (Manitoba Agriculture and Resource Development, and the Canadian Food Inspection Agency); plus two non-governmental organizations, the Manitoba Beef Producers, and the Manitoba Wildlife Federation. The task force’s primary goal was eradicating bovine ТВ from the Riding Mountain ecosystem. The primary reservoir species, undetermined at the beginning of the outbreak were elk, with whitetailed deer (Odocoileus virginianus), and cattle were the spillover species likely unable to maintain infection on their own without ongoing re-infection (Shury and Bergeson. 2011; Shury, 2014). A series of town hall meetings at the beginning of this process proved very confrontational and increased conflict (Brook and McLachlan, 2008; Brook, 2009). Vocal individuals advocated for extreme responses, including total park fencing, even though subsequent research showed that few people supported such responses (Brook, 2008). Research was initiated to learn more about cattle-wildlife interactions and to better understand the human dimensions behind some of the frustrations voiced by local cattle producers (Brook and McLachlan, 2008; Brook, 2009, 2010). These studies proved key in understanding both the wildlife-livestock interactions at a regional scale as well as the attitudes and beliefs of local ranchers, who proved key in helping eventually eradicate bovine ТВ from the National Park (Brook and McLachlan, 2006). Five integrated principles for collaborative disease management were learned from the successful eradication of bovine ТВ from the greater Riding Mountain Ecosystem (Table 16.1).
Adaptive management is a structured approach to intractable problems that involves instituting possible solutions, measuring or monitoring these actions, and adjusting these actions based on ongoing learning (Miller et ah, 2013; Thirgood, 2009). Options for ТВ management came from locally generated research through partnerships with universities as well as from international conferences and symposia. Annual management plans prioritized surveillance and monitoring in both wildlife and livestock and a jointly developed, transparent budget. The Riding Mountain Eradication Area (RMEA) was created in 2000 as part of zoning efforts to compartmentalize the disease and focus surveillance efforts on
Integrated Principles for Collaborative Socio-Ecological Management Learned From the Successful Eradication of Bovine ТВ at the Wildlife- Agriculture Interface in Manitoba, Canada
Use adaptive management
Have clear communication between decision-makers and communities
Incorporate multiple knowledge systems
Use long-term thinking
Prioritize innovation and flexibility during the planning, implementation, and evaluation phases
both livestock and wildlife (Lees et al., 2003). It also resulted in the creation of a wildlife laboratory to facilitate wildlife sample testing within the National Park.
A Stakeholder Advisory Committee and a Scientific Review Committee provided a forum to generate consensus for adaptive management, bringing together both wildlife and livestock interests with very different viewpoints and methods. The Stakeholder Advisory Committee used a professional facilitator, and the Science Advisory Committee was chaired by an independent scientist. These groups provided a mechanism for clear communication between decision-makers and communities. Mistrust between the National Park and local cattle producers was a serious obstacle at the beginning of the programme, with calls to eradicate the entire elk population within the park (Brook, 2009). This abated over time as more collaborative solutions, trust, and relationships were built within the structures of the task force.
Another effective method of communication was concurrent sociologic research, which resulted in numerous conversations between the primary researcher and local cattle producers over a cup of coffee at the farmer’s kitchen table (Brook and McLachlan. 2006, 2009; Brook, 2013, 2015) (Figure 16.1). This created not only an effective way for cattle producers’ voices to be heard, but also developed trust very quickly. Relationships were never perfect and other issues and conflicts that have occurred over decades over other issues, such as wolf control, remained (Stronen et al., 2007).
One of the most difficult aspects of the ТВ programme was the incorporation of multiple knowledge systems. Turning scientific knowledge as well as local ecological and traditional knowledge into effective policy decisions was very challenging (see Chapter 10 for more on healthy policy). Once it became clear, through epidemiological research, that bovine ТВ was restricted to one area in the western region of the park, management activities could focus on this area (Shury, 2015; Brook et al., 2013). Local ecological and scientific knowledge aligned very closely to identify this area (Brook and McLachlan, 2009). Subsequent actions included legislation to prohibit baiting of wild ungulates for hunting, construction of over 150 high fence hay storage areas to prevent
FIGURE 16.1 One-on-one discussion with rancher about elk and deer interactions with domestic animals on their farm. (Photo credit Ryan Brook.)
wildlife access to cattle feed, on-farm biosecurity measures, intensive livestock testing, and testing and removal of ТВ-infected wild ungulates through both liberal extended hunting seasons and helicopter capture of wild ungulates within the park. Indigenous hunters were recruited to assist with reducing ungulate population densities. Helicopter capture became less acceptable over time and eventually ceased. This adaptive management was enabled by incorporating different knowledge systems and stakeholder viewpoints.
Long-term thinking was another critical success factor. Communicating the persistent nature of bovine ТВ to policymakers, stakeholders, and communities ensured that expectations were realistic. "ТВ fatigue” affected government staff, local cattle producers, as well as hunters and indigenous communities, as the management programme spanned a period of over 20 years. It was vitally important that decision-makers understood that success may not be achieved within their four- or five-year mandate, but that progress was being made and eradication remained a valid long-term objective. Establishing trusting relationships between government agencies at different jurisdictional levels with very different mandates, and associated stakeholder groups, was important in creating a shared long-term vision at a landscape scale. Lack of trust is often the greatest barrier to successfully dealing with other wildlife reservoirs around the world.
The last lesson from ТВ management in Manitoba was the importance of innovation and flexibility in the planning, implementation, and evaluation phases of the cross-sectoral, disease management programme. Several novel diagnostic tests were adopted early for wildlife surveillance, some which were very effective in elk and white-tailed deer (Shury et al„ 2014). Understanding local opinions and values through social science research was important to build bridges with local stakeholders and to understand what management activities would have
FIGURE 16.2 Hay storage fence to prevent wildlife from accessing cattle forage. (Photo by Todd Shury.) a high likelihood of acceptance. This knowledge was very important for creating on-farm risk assessments which were used to tailor unique management approaches. Flexibility in how resources were spent resulted in shared management approaches, which resulted in over 150 hay storage fences being built on private ranches bordering the park (Gooding and Brook, 2014; Brook, 2015). Government agencies paid for the capital costs for these fences (Figure 16.2), while local landowners were responsible for operation and maintenance. This collaboration created a visible reminder to local cattle producers that they had a direct hand in managing bovine ТВ on their farms.
WILDLIFE SURVEILLANCE IN SRI LANKA
The need to be attentive to human dimensions of wildlife disease surveillance and control was also seen in Sri Lanka, where rabies is a zoonotic disease which occurs at the interface between humans, wildlife, and domestic animals (Sanchez- Soriano et al., 2019). Zoonotic diseases such as rabies, leptospirosis, and Japanese encephalitis remain significant public health threats in the country. A previous review of Sri Lanka’s emerging infectious disease preparedness (Dissanayake et al., 2012) noted a national vulnerability due to lack of information on the status of wildlife diseases. South Asia has been identified as a hot spot for zoonotic infectious disease emergence, but limited capacity has kept wildlife departments from being active participants in preparedness and response efforts. Coordinating and integrating surveillance activities was a key challenge in controlling animal rabies in Sri Lanka, a country w'hich has less developed wildlife health infrastructure and more limited funding than wealthier countries. Persistent challenges affecting collection of high-quality wildlife health data include lack of training, lack of access to facilities, and lack of communication amongst government departments with responsibilities for livestock, wildlife, and public health (Dissanayake et al., 2012). Logistic difficulties such as lack of instruments, materials, transport facilities, diagnostic facilities, advanced technologies, and trained personnel impede a cross-sectoral coordinated rabies surveillance system. Further wildlife disease surveillance constraints arise from reliance on convenience and opportunistic sampling. This prevents wildlife surveillance systems from meeting expectations for public health or domestic animal surveillance (Stephen et al., 2019) and leads to conflicting expectations between sectors on w'hat a wildlife disease surveillance system should produce.
Sri Lanka’s legislative mechanisms further complicated surveillance system development. The Fauna and Flora Protection Act No. 44 and its amendments, for example, require the collection and submission of wild animal samples to diagnostic laboratories to be done by staff of the Department of Wildlife Conservation (DWC). Transporting or keeping wild animals, their bodies, or parts by others are offenses under this Act. This discourages citizens or members of other government programmes from contributing samples for surveillance. Wildlife disease surveillance is a public good, but there is no encouragement of private citizens to submit w ildlife surveillance samples. The DWC manages most wildlife habitats, including nature reserves, national parks, jungle corridors, and marine reserves, but other forests are managed by the Department of Forests. DWC w ildlife veterinarians’ main duties are to prevent and control wild animal and zoonotic diseases and mitigate human-wildlife conflict. DWC veterinarians are minimally involved in domestic animal-related cases and public outreach. Even though DWC wildlife veterinarians are directly involved in handling and treating w ildlife and post-mortem procedures, they lack laboratory investigation capacity. This means disease investigation must go through the Department of Animal Production and Health (DAPH) veterinarians w'hose efforts are dedicated mostly to farm animals. Medical Officers of Health (MOH) and their laboratory infrastructure are also involved in diagnosing zoonotic wildlife disease, like rabies. Governance, accountability, and legal authorities in Sri Lanka lead to fragmented surveillance responsibilities and constrained options for collaborative rabies surveillance.
A university-government collaboration called the Sri Lankan Wildlife Health Centre (SLWHC) was developed to overcome some of these challenges (Nihal et al., 2020). The objective of the SLWHC is to track wildlife diseases and build capacity to inform conservation, agriculture, and public health actions (Kolia, 2020). The SLWHC helps centralize the flow of surveillance samples and information by engaging a diversity of stakeholders and programme implementers with interests in wildlife diseases. The SLWHC brings relevant government ministries responsible for domestic animals, human health, and wildlife management together for the first time to develop and govern a new wildlife diagnostics and surveillance programme. This allows for relationships to develop to facilitate better understanding of each other’s needs and capabilities. Establishing or facilitating relationships between DWC and DAPH officers benefitted a collaborative surveillance system. The SLWHC initially provided training and capacity development to its partner agencies to develop a shared knowledge base across partner organizations as well as to overcome some rabies surveillance logistic challenges. By empowering key stakeholders and enhancing core capacities, it is possible to address some disease surveillance constraints (Halliday et al„ 2012).
Through SLWHC-sponsored research, government agencies became aware of workplace or regulatory changes that reduced staff willingness to be involved in wildlife surveillance when wildlife disease management was not their primary responsibility. This was an issue particularly for field workers most likely to encounter sick or dead wild animals. Researchers met with local communities to understand their concerns about rabies and other wildlife diseases. Surveillance systems that are useful for communities and address the needs of regulatory agencies are often more sustainable and can enable the development of longer- term capacities (Malani and Laxminarayan, 2011). The SLWHC subsequently prioritized rabies as a targeted disease, because it was a priority shared across the DWC, DAPH, and MoH and local communities. Working on a shared priority can foster relationships needed to improve communications and trust across sectors dealing with wildlife health in the country. SLWHC partners explored innovative methods to use existing knowledge, personnel, and capacities. For example, a mobile phone-based surveillance system was shown to be effective for field-level disease investigation (Robertson et al„ 2010). The Sri Lankan experience highlights the need to design surveillance systems with the constraints, capacities, priorities, and direct input of all stakeholders in mind.