6 March 2006

Avian Influenza - Biosecurity for Zoological and other collections of birds

Zoological and other collections of birds are recognised to have possible specific considerations in relation to biosecurity.

Examples include:

" The size of the enclosure to allow adequate welfare;
" Enclosure design that could allow mixing with wild birds;
" Possible contamination by members of the public for educational purposes;
" Deliveries from commercial poultry premises;
" The need to move birds across long distances to other sites for the purposes of breeding programmes, etc; and
" Unique welfare and housing difficulties.

The biosecurity guidance in this document applies to such sites and is intended to assist site managers further with their individual site biosecurity planning. It supplements guidance advice available elsewhere from Defra, such as on the website at www.defra.gov.uk (Avian influenza site, Biosecurity section).

It is recommended that those responsible for biosecurity on such sites undertake a full risk assessment and that biosecurity plans are produced for each site, both for normal use and a contingency plan for a time of heightened threat. Factors to be considered in the contingency plans are given below.

The aims of biosecurity in this group of sites are:

1. To prevent such UK sites becoming infected with AI and other diseases should they enter the country.
2. To prevent the spread of disease from such sites to birds on other sites.

As normal practice, zoos and other sites should consider undertaking the following processes:

1. Division of the zoo or site into stand-alone epidemiological units.
2. Risk assessment for each of the epidemiological units.
3. A biosecurity assessment and contingency plan for the whole site and each epidemiological unit.

Best practice indicates that these processes should be undertaken immediately.

Epidemiological Units
An epidemiological unit holds a group of birds which are in contact, by any means, i.e. same air space, shared utensils, shared staff, bedding etc, and therefore disease could be transmitted between them. For example, in zoos this may be a single building or single large aviary, a group of aviaries with adjoining boundaries or a number of adjoining waterfowl enclosures.

By defining effective epidemiological units, each with its own risk assessment, the premises can be more objectively considered if it is ever the subject of other disease control measures. The ultimate aim is to minimise the risk profile of each unit.

Biosecurity

In addition, general up-to-date biosecurity guidelines are available on the Defra website, and should also be used for guidance. It must be noted that infectious faeces are the primary source of infection. Hence care must be taken regarding the source of bedding and the disposal of waste.

Welfare considerations may dictate that certain birds may not be kept in a very biosecure fashion. However this would increase the epidemiological unit's risk profile.

Site Biosecurity Examples

The following measures should ideally be implemented on a site-wide basis.

1. All birds brought into a collection should be isolated for at least 14 days and monitored for signs of disease, including possibly testing for avian influenza, especially during any period of heightened risk.
2. Staff who work with birds should ideally not work with other birds elsewhere. If this situation cannot be avoided, they should ideally shower and change clothing on entering the zoo or site.
3. Minimise potential contact with wild birds. If possible, this is best achieved by housing birds indoors. If this is not possible, aviary roofs can be covered with plastic or temporary structures can be erected. Netting enclosures also reduces exposure to wild birds. The size of netting used should be decided based on assessment of the practical aspects of erection and maintenance, and by the species of birds that you require to exclude. If your zoo has a particular problem with wild ducks, etc, then it is advantageous to target these species, whereas if the majority of birds potentially contaminating food and water are starlings and sparrows, smaller gauge would be more suitable. The choice of protective netting should be a practical balance between the size of the enclosure, cost, and the degree of protection from contact with wild birds. For example, very large enclosures covered with small size netting may actually encourage birds to rest on it. Larger size netting would actually discourage this.
4. Only essential vehicles should enter the bird areas of the zoo or site. These should be free of obvious contamination and have their wheels and wheel arches disinfected with a Defra-approved product if the risk is heightened.
5. Pest control programs should be in place.
6. All birds should be checked at least daily. If there is unusually high mortality and Avian influenza is suspected, there is a duty to contact your local Animal Health Office to report such suspicion.
7. Maintain a system to identify each bird and keep a record of each.
8. All crates used to transport birds, containers and other equipment should be cleaned and disinfected before and after each use. Equipment should not be moved into different bird epidemiological units without cleaning and disinfecting it first. You are advised not to reuse cardboard containers.
9. Buildings, feed stores and containers should be sealed to prevent animals and wild birds contaminating feed, nesting or roosting.
10. Try to reduce faecal contamination of enclosures from wild birds - remove overhangs, perches, etc.
11. It is advised that birds not be accepted off the street from the public, especially if the bird is or was sick.
12. If none of these options are possible, then as a minimum, feed and water should be protected by undercover feeding or dispensers. Unprotected ponds which attract wildfowl should warrant particular consideration, i.e. covering, sealing off if possible, etc. Accumulation of standing water and spilled feed are to be prevented if possible as they could attract wild birds.

Further contingency plans for biosecurity of epidemiological units at a time of heightened risk.

1. Separate personnel should ideally service each epidemiological unit.
2. Confine birds into inside areas if possible but ensure that this does not cause welfare problems.
3. Consideration should be given to domestic poultry, ducks or game birds being removed from the premises, especially at times of increased risk. This would be subject to any Defra movement restrictions in place.
4. During periods of increased risk, consideration should be given to staff and visitors entering the zoo or site being able to disinfect their footwear using a Defra-approved product. Staff should consider changing clothing/footwear on arrival and departure.
5. Should there be a period of increased risk, consideration should be given to areas of the collections that may have to be altered to prevent contamination of the area by visitors/non-bird staff, of zoo or other site birds.
6. Each epidemiological unit should ideally have dedicated clothing / footwear / food bowls / equipment.
7. Consideration should also be given to any use of poultry and poultry products as food items for certain birds - alternatives are available such as rodents, etc.
8. Birds should not move between epidemiological units. This may require containing pinioned waterfowl or other free-ranging collection birds normally allowed free access to the zoo or site (e.g. peacocks, ducks etc).
9. Avian influenza can possibly remain viable in water for several months. Where water courses run through aviaries, measures should be taken to try to prevent wild birds contaminating the water upstream, unless impractical. An epidemiological unit should NOT ideally share watercourses or similar sources with another unit; if this situation arises they should be considered as only one epidemiological unit.

For further information and guidance on Avian influenza and biosecurity, visit the Defra website at www.defra.gov.uk or phone your local Animal Health Office.