FAQs Regarding The Suffolk Bird Flu Outbreak

Main Category: Bird Flu / Avian Flu
Also Included In: Veterinary;  Water - Air Quality / Agriculture;  Public Health
Article Date: 11 Feb 2007 - 7:00 PDT

email to a friend   printer friendly   opinions  

What does confirming H5N1 in a poultry farm mean for animal health?

Defra have put in place a 3km Protection Zone and 10 km Surveillance Zone around the infected premises, requiring certain biosecurity measures, the housing of birds, and movement restrictions. A wider Restricted Zone has been put in place which covers east Suffolk and South East Norfolk bounded to the west and the north broadly covered by the A140 and A47 respectively, and is approximately 2090km2. It requires the isolation of poultry from wild birds and permits movements only under licence. All bird keepers, throughout the UK should continue their efforts to maintain high levels of biosecurity (please see the Defra website for further biosecurity advice), and develop their plans to bring their birds indoors should it become necessary.

What are the zones and what do they mean?

Protection Zone (PZ) 3km

Measures:

-- Housing or isolation of poultry and other captive birds;
-- Movement restrictions on poultry, other captive birds, mammals, eggs, poultry meat, carcasses and poultry waste except where licensed;
-- Biosecurity measures for people, premises and vehicles;
-- A ban on bird gatherings;
-- A ban on the release of game birds.

Duration: At least 21 days after the preliminary cleansing and disinfection of the infected premises and then becomes part of the surveillance zone. The duration of the PZ will take account of surveillance in the area to identify whether or not disease is present.

Surveillance Zone (SZ) 10km

Slightly less restrictive.

-- Movements of poultry, other captive birds and eggs restricted except under licence.
-- Housing or Isolation of birds
-- Biosecurity measures for premises, people and vehicles;
-- A ban on the hunting of wild birds, the release of game birds and bird gatherings.

Duration: At least 30 days after the preliminary cleansing and disinfection of the infected premises. The duration of the SZ will take account of surveillance in the area to identify whether or not disease is present.

Restricted Zone (RZ) 2090km2

-- Housing or isolation of poultry from wild birds
-- Movements under license

To note:

-- The duration of the PZ and SZ will take account of surveillance in the area showing that there is no disease present.
-- National restrictions â€" All bird gatherings, including fairs, markets, shows, exhibitions and pigeon races, are banned in England, Scotland and Wales. All such gatherings planned over the next few weeks must be cancelled.

What are the next steps?

-- Culling was completed at approximately 18:45 on 5 February.
-- All carcasses were removed from the site on 5 February.
-- Rendering is estimated to be completed by end 8 February.
-- The material that is left as a product of the rendering is being stored safely on site at the rendering plant. This material no longer carries infection. It will be incinerated or co-incinerated at an approved plant. No timetable for this has been confirmed.
-- Preliminary Cleansing & Disinfection (C&D) began on Monday 5 February. We are not able to be definite about when this will be finished, but current estimates are Thursday 8 February. Preliminary C&D is undertaken by the SVS or a contractor under the supervision of the SVS. It involves the spraying of all material, equipment and housing with approved disinfectants.
-- Secondary C&D is the responsibility of the keeper so we cannot be definite about when this will start. Secondary C&D is the responsibility of the poultry keeper, but will also be done under the supervision of the SVS. It involves the removal of all organic matter, followed by washing and de-greasing, followed by further spraying if disinfectants
-- Re-populating of the site cannot occur until at least 21 days after the secondary C&D has been completed.
-- Legislation states that the PZ must remain for a minimum of 21 days after preliminary C&D has been completed. At this point, after a veterinary check on all poultry/ bird premises in the PZ, the zone becomes part of the SZ and all the SZ measure apply.
-- Legislation states that the SZ must remain in place for a minimum of 30 days after preliminary C&D has been completed.
-- The length of time that the RZ stays in place will be based on veterinary risk assessment.
-- According to the OIE, the international health organisation, highly pathogenic notifiable avian influenza free status can be regained 3 months after a stamping-out policy, including disinfection of all affected establishments; and provided that surveillance is carried out during that three-month period.

How is the farm cleaned to ensure no infection is on site?

Preliminary Cleansing and Disinfection (C&D) is undertaken by the SVS or a contractor under the supervision of the SVS. This involves the spraying of all material, equipment and housing with approved disinfectants.

Secondary C&D is the responsibility of the poultry keeper, but will also be done under the supervision of the SVS. This involves the removal of all organic matter, followed by washing and de-greasing, followed by the spraying of all equipment and housing with approved disinfectants

What exactly is involved in this investigation?

Essentially investigations to determine when infection was introduced and all possible sources of infection. This involves possible movements of birds and animals and their products, people, vehicles, equipment, feedstuffs, bedding material, etc. In this case there has been specific involvement of expert ornithologists to assist with investigating a possible wild bird source. Patrolling the previously identified reserves containing large populations of the species of interest to obtain dead birds have been increased to at least twice per week and additional reserves in the area have been included in this active surveillance. Investigations are naturally concerned with the possible transmission of infection to other poultry premises.

The results of molecular genetical analyses are also important in the epidemiological investigations.

Did H5N1 spread to the other sheds?

As part of our epidemiological investigation samples were taken from all the other 21 sheds on the infected premises when the birds were culled. The turkeys were clinically healthy, but initial test results have indicated that some of the birds in 3 additional sheds were infected with avian influenza. All tests are not yet completed and we will make the results available when they are confirmed.

What information did Defra know and when about poultry imports from Hungary?

We were aware of regular consignments from Hungary in compliance with EU intra-community trade legislation. Our understanding was that they came from uninfected parts of the country. Test results have revealed that the strain of the virus found in the turkeys may be identical to the strain found in Hungary. In addition yesterday (Thursday) new information from the laboratories came to light which revealed that the transmission for the virus is poultry to poultry. This makes transmission direct from Hungary more likely, rather than a pathway via wild birds, hence the announcement today of our investigation yesterday.

If you think that wild birds are unlikely why not lift housing and shooting restrictions in the area?

Our epidemiological investigation is on-going, we have not yet ruled out infection in the wild bird population in the area, or any role that they may possibly play in its mechanical transfer. Until our investigations are complete restrictions therefore need to remain in place. Whatever the means by which infection reached the area now that it is present we need to ensure that it does not spread further via wild birds or other movements, the restriction zone achieves that.

http://www.defra.gov.uk

• Additional
• References
• Citations