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Addressing zoonotic diseases on a global scale

Vet Advice with Dr. Ron Clarke

Controlling disease will become more difficult as new diseases constantly emerge, and novel environmental, social and financial pressures across the globe change the face of disease control.

In March 2019, the World Health Organization, the Food and Agriculture Organization of the United Nations and the World Organization for Animal Health launched a guide for countries using a One Health approach to control zoonotic diseases. The guide became available internationally in multiple languages in October 2019.

Zoonotic diseases such as avian influenza, rabies, Ebola, Rift Valley fever, food-borne pathogens, plus larger health issues such as antimicrobial resistance, affect human and animal health in major ways. Zoonoses affect people’s livelihoods everywhere and play havoc with international economies.

Many countries now recognize the benefits of employing multidisciplinary, One Health devices to address health threats at the human-animal-environment interface. This approach strengthens national and global health security. One Health principles influenced how World Health Organization health regulations came on-stream in 2005. One Health principles were catalysts for the international standards in animal health, veterinary public health, zoonotic disease control and animal welfare eventually advanced by the World Organization for Animal Health. One Health serves as a beacon, guiding the future of these organizations.

The tripartite collaboration between the Food and Agriculture Organization of the United Nations, World Organization for Animal Health and World Health Organization reflects a longstanding and successful partnership using One Health to address challenges in public health, animal health (both domestic and wildlife) and the environment facing our world today.

Unfortunately, the document is written in typical government fashion — allusive and laced with many acronyms. Although awkward to read, veterinarians and producer organizations associated with control of zoonotic diseases need to be aware of the Tripartite Zoonotic Guide and take time to understand its contents.

As we discovered in 2003 with BSE, initial complacency followed by overreaction can create an international crisis. Used properly, the One Health approach helps detect disease, assess a disease’s importance, and then gives direction to an appropriate response. This applies to both emerging and endemic (already present) zoonoses.

Controlling disease will become more difficult as new diseases constantly emerge, and novel environmental, social and financial pressures across the globe change the face of disease control.

The last guide to partially address zoonotic disease control appeared in 2008. The 2019 guide is flexible enough to cover other health threats at the human-animal-environment interface (e.g. antimicrobial resistance and food safety). It outlines operational tools, best practices related to interagency co-operation, data management and standard operating procedures.

While recognizing that a One Health approach has been used effectively to address current zoonotic disease threats, the process often declines into a state of disuse once the emergency passes. To ensure effective implementation, key operational components must be made routine and sustainable. Factors in establishing sustainability include:

  • High-level political will establish commitment and engagement from all relevant sectors.
  • Sufficient resources and the ability to equitably distribute them.
  • Maintaining context and ensuring activity within each country is aligned with the national ability to respond.
  • Mutual goals — internationally — so that strategies and activities are based on shared needs, common objectives and health priorities, which translate into common benefits.
  • Strong governance with compliance to existing regional and international standards.
  • Effective and routine co-ordination and communication among relevant sectors.
  • Effective health systems within individual sectors.
  • Ability to recognize success.

A multi-sectoral One Health approach to zoonotic disease control makes the best use of limited resources and improves the efficiency and effectiveness of zoonotic disease management. Results, measured simply as reduced morbidity and mortality, can be quickly tallied. Avoiding duplication of activities by, for example, sharing laboratory facilities between sectors, reduces costs. Improving zoonotic disease management reduces risk and societal losses such as the livelihood of small producers, distressed human nutrition, trade restrictions and displaced tourism. Strong co-ordination between all players enhances communication between partner organizations and augments credibility with national and international stakeholders.

One Health better addresses the social context of zoonotic disease, especially the vulnerability of some groups of people. Multi-agency participation improves the ability to establish partnerships with social scientists and directs attention to factors such as gender, Indigenous and minority populations, and diverse cultural practices.

The World Organization for Animal Health emphasizes that it’s important to realize that not all information collected is valuable, and that not all valuable information gets collected. The first step in the One Health process is to use a multi-sectoral approach to prioritize endemic and emerging zoonotic diseases. U.S. officials at the Center for Disease Control have developed a One Health zoonotic disease prioritization tool.

The Center for Disease Control also collaborates with countries and other partners to conduct prioritization workshops to identify the zoonotic diseases representing the greatest national concern in each country. Zoonotic diseases commonly prioritized include viral hemorrhagic fevers such as Ebola virus and Rift Valley fever, zoonotic influenza viruses, rabies and anthrax.

The World Organization for Animal Health’s view is that controlling pathogens at their animal source is the most effective and economic way of protecting people. Consequently, we need global strategies to prevent and control pathogens and protect public health. Where it starts is at the human-animal-ecosystem interface.

About the author


Dr. Ron Clarke

Dr. Ron Clarke prepares this column on behalf of the Western Canadian Association of Bovine Practitioners. Suggestions for future articles can be sent to Canadian Cattlemen ([email protected]) or WCABP ([email protected]).

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