Infectious diseases in animals impact food production and drive antibiotic use in this sector. The main diseases being treated with antibiotics are common endemic infections such as mastitis, pneumonia and diarrhea. These diseases also cause decreased productivity. Thus, disease prevention is an important factor both to lower antibiotic use and to increase the productivity of the animal.
To have basic routines for prevention and control of infectious diseases at farms, in veterinary practices and in other places where humans and animals interact decreases the risk of infection and is thereby crucial for minimizing antibiotic use and the risk of spreading antibiotic resistant bacteria. Increasing number of reports demonstrate the economic benefit of applying disease prevention measures such as improved heard management, biosecurity and vaccination. These measures can also lead to substantial reduction in antibiotic use. In one study of pig farms, improving health status among animals via biosecurity measures decreased the total antibiotic use by 52% from birth to slaughter without reducing productivity.
Disease prevention in aquaculture – the Norwegian example
Norway is one of the world’s main salmon producers, with an annual production of Atlantic salmon of 1.3 million tons. It is also one of the countries with the lowest use of antibiotics in the aquaculture sector. Thus, large scale production of salmon is possible without regular use of antibiotics. Norway has managed to dramatically decrease the use of antibiotics, which peaked in 1989-90. At the same time the aquaculture production has increased more than tenfold. How? The most important factors have been:
- Development of new vaccines and vaccination strategies
- Sanitary measures to prevent horizontal disease transmission (between sites and between salmon year classes)
- Strong legislative measures and consensus between governmental authorities and the industry to focus on disease control
Principles of biosecurity
There are two main principles of biosecurity that aim to prevent infectious diseases in animals: to diminish exposure to the infectious agent and to increase the animal’s ability to resist disease.
Partial exclusion from exposure: Prevention
By disease prevention, the spread of the pathogen is minimized to a level where no or only a few animals in the heard become sick. Important measures to prevent the spread of diseases are:
- Improved hygiene
- Isolation of sick animals
- Avoiding introduction of animals of unknown health status into the heard
- Use of all-in, all-out concept with cleaning and disinfection between batches of animals
Total exclusion from exposure: Eradication
Eradication of specific infections can occur on several levels such as locally on individual farms, within regions or on a national level – but the basic means to achieve the goal are the same as for prevention. To be able to eradicate a specific infectious disease, the pattern of spread of the infectious agent must be known. Also, diagnostic capacity to identify infected animals or holdings as well as technical infrastructure to be able to stop the spread of the disease and eliminate the source of infection are important. After the eradication, measures to prevent reinfection must be implemented.
Measures to increase host resistance: Animal welfare
The end goal of sustainable farming is to reach a health oriented farming system, where both the physiological and behavioral needs of the animals are met. To improve the disease resistance of an animal, several factors can be considered, such as:
- Nutritional needs
- Animal rearing and housing
- Management routines
Also, immunity of the animal to specific infections can be stimulated by the use of vaccines. Vaccination is an efficient measure to prevent specific bacterial diseases, including bacterial infections.
Infection prevention efforts are also important to reduce the spread of zoonotic diseases through the food chain. The global burden of foodborne diseases is considerable. Foodborne hazards caused an estimated 600 million foodborne illnesses and 420,000 deaths in 2010. Particularly affected are children and persons living in low-income areas. Improving food security is highlighted as one of the priority areas of the United Nations Sustainable Development Goals, to be achieved in 2030. Ensuring food security will not be possible without also ensuring safe food.
Prevention of foodborne antibiotic resistance
Also antibiotic resistant bacteria can spread via food, and ensuring food safety is important to limit the spread and effects of antibiotic resistance. Both zoonotic bacteria and the microbiomes of the animals can carry resistance, and these bacteria may contaminate the meat during slaughter. Crops that comes in contact with animal manure may also be contaminated. Measures to reduce the risk of spreading antibiotic resistance via food are the same as for other food safety issues, and includes the whole food chain such as disease prevention at farm, and appropriate hygiene from farm to fork.
Guidelines on processes and methodology for risk analysis concerning foodborne antibiotic resistance related to animal use of antibiotics have been developed. These guidelines also provide advice on appropriate risk management activities to reduce such risk.
Work to improve infection prevention
There are no universal best practices for disease prevention at animal farms, but there are a number of measures that can be taken to improve infection prevention and control and reduce antibiotic use. Getting started and Interventions provides more information and tools to facilitate the work.
|Information on aquatic and terrestrial animal diseases||Information portal from OIE with resources and information on more than 100 diseases affecting animals. Diseases listed in alphabetical order and for the type of animal.|
|Principles and Strategies for the Prevention and Control of Infectious Diseases in Livestock and Wildlife||Book chapter that summarizes the main principles and strategies for prevention and control of infectious diseases in animals. See chapter 25 (in Part 2 of Prevention of Infectious Diseases in Livestock and Wildlife).
|Foodborne zoonotic diseases||Information portal on foodborne zoonoses from the European Food Safety Authority.
|Antibiotic resistance from the farm to the table||Infographic from CDC that describe how antibiotic resistant bacteria can spread to humans via food and the consequences.|
|Antibiotic Use in Food Animals Poses Risk to Public Health||Article. Information page from PEW discussing current evidence on antibiotic use in food animals and the impact on health, with links to further scientific evidence.|