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Diseases - Avian Influenza - FAQs

General Questions

1. What is Avian Influenza?

Avian influenza is a highly infectious disease caused by an Influenza type A virus that normally infects birds. The disease in birds can manifest itself in a number of different forms ranging from relatively mild to severe. Certain wild birds, particularly waterfowl, commonly carry the milder forms.

2. What is the significance of the different sub-types of Avian Influenza?

There are many different sub-types of avian influenza, grouped into a less serious - low pathogenic - form ( LPAI) and a more serious - highly pathogenic - form ( HPAI). The viruses are described by their major antigen determinants, H (for haemagglutinin) and N (neuraminidase). The current strain of concern is a highly pathogenic H5N1.

In birds we are mainly concerned with H5 and H7 subtypes. It is known that the LPAI H5 and H7 virus subtypes can mutate into the highly pathogenic form that causes serious illness and deaths in birds, although in water fowl the disease may not be apparent.

3. What are the symptoms of Low Pathogenic Avian Influenza?

Typically, infection with LPAI is often difficult to detect, with very few if any clinical signs. An infected flock might show signs of respiratory distress, diarrhoea, a loss of appetite or a drop in egg production of more than 5%. If you are suspicious your flock has any form of avian influenza you MUST contact your local animal health office immediately.

4. What are the symptoms of Highly Pathogenic Avian Influenza?

Typically this form of the disease presents suddenly, often with very high mortality, with affected birds developing swollen heads, a blue colouration of the comb and wattles, dullness, lack of appetite, respiratory distress, diarrhoea and significant drop in egg production. However, there can be considerable variation in the clinical picture and severity of the disease. If you are suspicious your flock has any form of avian influenza you MUST contact your local animal health office immediately.

5. How is Highly Pathogenic Avian Influenza controlled?

In the event of an outbreak, all birds on an Infected Premises are killed and their carcases disposed of. There would be movement restrictions and control on eggs, meat and anything likely to spread disease within a 10 km radius around the infected premises.

6. What surveillance is being carried out?

Surveillance of wildfowl for avian influenza is one of our best defences against incursion of the disease in poultry, as it gives early warning of the presence of the disease. More detail on surveillance can be found on the Surveillance of Wild Birds webpage.

7. What powers do Scottish Ministers have to deal with Avian Influenza?

The Avian Influenza and Influenza of Avian Origin in Mammals (Scotland) Order 2006 gives powers for preventative measures and for measures to be taken on confirmation of either high or low pathogenic avian influenza.

If H5N1 is found in poultry, these powers are supplemented by the Avian Influenza (H5N1 in poultry) (Scotland) Order 2007. The legislation requires that a protection, surveillance and restriction zone are set up, and that extra controls are placed on poultry, eggs and game.

If H5N1 is found in wild birds, the Avian Influenza (H5N1 in Wild Birds) (Scotland) Order 2007 provides powers to set up wild bird control and monitoring areas and to take a range of biosecurity measures to contain the disease.