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Food-Producing Animals

Disease Outbreaks

Disease emergence and spread do not respect geographical boundaries. This is why it is important to have the necessary tools available to combat and control disease. Efficient early warning and forecasting of disease trends through surveillance systems is key to effective containment and control. Early intervention such as the use of vaccines during a disease epidemic often leads to better outcomes with reduced disease burden and associated economic impact.

Avian Influenza (H5N8)

Avian Influenza Outbreak in 2016

In September 2016, the UN Food and Agricultural Organization (FAO) released a warning about the spread of HPAI H5N8, when it was found in 17 water birds at Ubsu-Nur Lake in Russia. Despite this early warning, H5N8 spread south into India, affecting several states, and west into Europe. Now, H5N8 has been detected in a number of EU member states and has spread even further afield. This is the fourth wave of intercontinental movement of HPAI H5 viruses since 2005 and the spread of the virus is presumed as being mainly due to migratory wild birds.

When possible, vaccination of birds is the best prevention method in combination with stamping out, biosecurity and surveillance measures particularly in areas with high poultry density. Prevention measures help to ensure that birds do not become sick and die and the spread of the virus can be reduced or stopped. 


Q: What is Avian Influenza?
A: Avian influenza is a respiratory disease of birds caused by a virus which occurs in low pathogenic and high pathogenic varieties. Outbreaks of low pathogenic avian influenza (LPAI) are common around the world, and are generally easily controlled, whereas the highly pathogenic versions of avian influenza (HPAI) are more serious due to the very high mortality rate in affected birds.

Avian influenza is most common in wild waterfowl species , but has also been reported in many common species of poultry, including chickens, ducks, turkeys, geese, pheasants and quail, as well as in a variety of other birds like parrots, cockatoos, and parakeets. Some species are more resistant to infection or can be asymptomatic transmitters of the disease.

Q: How is Avian Influenza spread?
A: Avian influenza is primarily spread by direct contact between healthy and infected birds, or through indirect contact with contaminated equipment or other materials. The virus is present in the faeces of infected birds and in secretions from their noses, mouth and eyes. The virus can spread into domestic flocks kept outdoors through faecal contamination from wild birds, whereas infection among indoor flocks is spread via airborne secretions and faeces. The spreading of the virus through faeces and secretions is often referred to as the “shedding” of the virus.

Q: What happens when avian influenza is detected or suspected in a bird or flock?
A: High Pathogenic Avian Influenza (HPAI) is a reportable disease by the World Organization for Animal Health (OIE). OIE has developed animal health standards classifying the highly pathogenic strains as reportable diseases. Any outbreak should be immediately reported to local and national animal health authorities.

Q: What can be done to prevent Avian Influenza?
There is no single solution to prevent avian influenza, but there are three types of measures that are used in conjunction with each other. Firstly, biosecurity and surveillance measures must be introduced, these include:

  • quarantining infected farms; 
  • restrictions on the movement of poultr y in areas surrounding confirmed or suspected infections; 
  • stringent hygiene measures such as using protective clothing and disinfecting vehicles passing through infected areas to prevent the spread of the virus through contaminated clothes or equipment; 
  • surveillance of wild birds and domestic poultry in areas surrounding confirmed or suspected infections 

Secondly, “stamping out” or culling of infected birds is also used to prevent the virus spreading;

  • All birds in a specified location (e.g. a farm) must be culled. 
  • The carcasses of culled birds must be appropriately disposed of; this is usually done via burial or burning. 
  • Birds in specified zones surrounding an outbreak may also be culled.

Thirdly, to prevent further spread of the infection, a vaccination programme can also be implemented when a vaccine is available taking the following into account:

  • Vaccination is a prevention strategy, 
  • Vaccination does not always prevent infection, but the vaccinated bird does not become ill and die as unvaccinated infected birds do. 
  • If a vaccinated bird becomes infected, it either does not excrete (“shed”) the virus or sheds much lower levels of virus than an infected unvaccinated bird and subsequently stops shedding the virus.

Q: What can be done to cure an infected bird of avian influenza?
A: There is currently no cure for highly pathogenic avian influenza. Current practice in most regions of the world requires the culling of infected birds, not treatment, hence prevention is extremely important.

Q: Does avian influenza present a risk to human health?
A: While most strains of avian influenza are found to exclusively infect birds, there are some strains such as H5N1, H7N9, and H5N6, which have caused severe illness or death in people. The current H5N8 strain has not yet been found to cause disease in humans.

Q: Does the spread of H5N8 strain of avian influenza threaten the safety of the food supply?
A: Firstly, the chance of infected poultry entering the food supply is extremely low. Secondly, in the unlikely event that contaminated poultry products reaches the food supply stage, the level of virus would be extremely low and present no danger of infection provided that the food is properly cooked.

Q: Is it true that large commercial poultry operations facilitate the spread of the disease?
A: No, in fact just the opposite is true. Large commercial poultry operations, which raise birds indoors, use biosecurity measures designed to keep birds as disease-free as possible as well as continuous monitoring by veterinarians. Many of these safeguards are not available to producers when flocks are raised outdoors.

Useful links

European Commission:

OIE - The World Organisation for Animal Health:

UN FAO - United Nations Food and Agriculture Organisation:

WHO - World Health Organisation:

ECDC - European Centre for Disease Prevention and Control:

Friedrich Loeffler Institute:

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