Q&A on avian bird flu

As the poultry sector waits to find out if the outbreak of high pathogenic avian influenza in East Yorkshire can be contained, the British Poultry Council has issued the following Q&A guide to the problem.

What is bird flu?

Avian influenza is a virus that causes disease in birds. Poultry, pigeons and wild or migratory birds, such as ducks, swans, and geese, can become infected with the virus. There are two forms of the virus: high pathogenicity (HPAI) and low pathogenicity (LPAI). Pathogenicity indicates the severity of the disease if the bird contracts the virus.

What is the risk to public health?

In this case Defra has stated that the risk to public health is very low. Some strains of avian influenza can pass to humans, but this is very rare. It usually requires very close contact between the human and infected birds.

Does bird flu affect the meat I eat?

No. The Food Standards Agency advises that properly cooked poultry and poultry products, including eggs, are safe to eat.

What does the name mean?

The name, e.g. H5N1, represents the particular strain of the virus. The H and N numbers represent two of the eight genes associated with a strain. LPAI strains can evolve over time to become HPAI, but all currently known HPAI strains are either H5 or H7.

Is this the same strain as the recent outbreaks in the Netherlands and Germany?

We don’t yet know. Defra will confirm the strain of the virus as soon as testing is complete.

See also: Yorkshire bird flu outbreak ‘very low risk’ to humans

How was this case reported?

The company, Cherry Valley, noticed a drop in egg production (on its own, not a suspicion for bird flu), which after a period of time was joined by an increase in mortality in the flock. At this point there were sufficient symptoms for a suspicion of bird flu and, as a notifiable disease, it was reported to the APHA who then took official samples. Upon confirmation of HPAI controls measures were put in place.

Have the birds on the farm been culled?

Not yet. This will be carried out under the control of the authorities over the next day or so. Once this is complete the farm will be thoroughly disinfected and cleaned.

What are control zones?

The protection zone (3km) and surveillance zone (10km) are put in place to control movement of poultry within and out of the area. Additionally within the zone all poultry should be housed and measures taken to maintain separation from wild birds. Movement of birds, for example to the slaughterhouse, is then carried out under official licence.

Will it spread?

We don’t know yet. The response was thorough and hopefully rapid enough to contain the outbreak on the one farm. Increased surveillance and high vigilance by poultry keepers are essential to monitor the surrounding area for further incidents.

How can you spot avian influenza in birds?

The main clinical signs of HPAI in birds are:

• swollen head
• blue discolouration of neck and throat
• loss of appetite
• respiratory distress such as gaping beak, coughing, sneezing, gurgling, rattling
• diarrhoea
• fewer eggs laid
• low pathogenic avian influenza (LPAI) is usually less serious. It can cause mild breathing problems, but affected birds will not always show clear signs of infection. The severity of LPAI depends on the type of bird and whether it has any other illnesses.

What if I work with birds?

If you work with birds that are suspected of having highly pathogenic avian influenza, it is important that you are protected from exposure.

If the virus was transmitted to humans the most likely route would be by breathing in dust and mist generated by infected birds and by not washing hands after handling infected birds or contaminated equipment and clothing. The virus can also be spread between bird houses and farms by moving contaminated equipment or machinery. It is important that you use the right equipment and good hygiene methods to protect yourself and your colleagues.

The HSE guide can be found at: www.hse.gov.uk/biosafety/diseases/aisuspected.pdf

Is production outside of the control zones affected?

No. Outside of the control zones production continues as normal. However, bird flu is taken very seriously by the whole British poultry sector and all producers are rigorous in applying their own controls. This is particularly important given that the movement of wild birds at this time of year makes this an unpredictable situation. However, with high vigilance and rapid response it is controllable and the impact on farmers can be minimised.