Zoonotic Diseases
Primary reference(s)
WHO, no date. Zoonoses: Managing public health risks at the human-animal-environment interface. World Health Organization (WHO). Accessed 14 September 2020.
Additional scientific description
A zoonotic disease is any disease that is naturally transmissible from vertebrate animals to humans. Animals therefore play an essential role in maintaining zoonotic infections in nature. They may be bacterial, viral, or parasitic, or may involve unconventional agents. As well as being a problem for public health many of the major zoonotic diseases prevent the efficient production of food of animal origin and create obstacles to international trade in animal products (WHO, no date).
Zoonotic diseases can be transmitted to humans in a number of different ways which vary depending on the specific disease. In addition to direct contact with animals they may be transmitted by: transmission from person to person; inhalation of spores or contaminated dust; consumption of unpasteurised dairy products or contaminated food; consumption of contaminated water; skin exposure to spores or contaminated water; and animal or insect bites/scratches (CDC, no date).
Zoonotic diseases comprise a large percentage of all newly identified infectious diseases as well as many existing ones. There are over 200 known types of zoonotic disease (WHO, 2020).
Some zoonotic diseases begin as a zoonosis but later mutate into human-only strains, for example human immunodeficiency virus (HIV). Others can cause recurring disease outbreaks, such as Ebola virus disease and salmonellosis (WHO, FAO and OIE, 2019).
Metrics and numeric limits
Not applicable.
Key relevant UN convention / multilateral treaty
International Health Regulations (2005), 3rd ed. (WHO, 2016).
Examples of drivers, outcomes and risk management
The World Health Organization (WHO) in partnership with the United Nations Food and Agricultural Organization (FAO) and World Organisation for Animal Health (OIE), leads the development of global norms and standards for zoonotic diseases, as well as technical work on pathogen detection, risk assessment and management (WHO, FAO and OIE, 2019).
Prevention methods for zoonotic diseases differ for each pathogen; however, several practices are recognised as effective in reducing risk at the community and personal levels including safe animal husbandry, increased hygiene measures and standards for clean drinking water and waste removal. Some zoonoses, such as rabies, are 100% preventable through vaccination and other methods (WHO, 2020).
Antimicrobial resistance is a complicating factor in the control and prevention of zoonoses. The use of antibiotics in animals raised for food is widespread and increases the potential for drug-resistant strains of zoonotic pathogens capable of spreading quickly in animal and human populations (WHO, 2020).
Markets selling the meat or by-products of wild animals are particularly high risk due to the large number of new or undocumented pathogens known to exist in some wild animal populations (WHO, 2020).
References
CDC, no date. Zoonotic Diseases. Centers for Disease Control and Prevention (CDC). Accessed 20 September 2020.
WHO, no date. Zoonoses: Managing public health risks at the human-animal-environment interface. World Health Organization (WHO). Accessed 14 September 2020.
WHO, 2016. International Health Regulations (2005), 3rd ed. World Health Organization (WHO). Accessed 26 September 2020.
WHO, 2020. Zoonoses Fact Sheet. World Health Organization (WHO). Accessed 20 September 2020.
WHO, FAO and OIE, 2019. Taking a Multisectoral, One Health Approach: a Tripartite Guide to Addressing Zoonotic Diseases in Countries. World Health Organization (WHO), Food and Agriculture Organization of the United Nations (FAO), World Organisation for Animal Health (OIE). Accessed 20 September 2020.