Scottish wild bird high pathogenicity: avian influenza response plan

5. Avian influenza GB wild bird surveillance

APHA carries out year-round avian influenza surveillance of dead wild birds submitted via public reports and warden patrols (e.g., carried out by local authorities and by non-government organisations at reserves), across Great Britain, on behalf of the Scottish Government and the other GB administrations, to inform the disease risk for domestic poultry, captive birds and human health.

The public are encouraged to report findings of dead wild birds using the online reporting system or by calling the national GB telephone helpline (03459 33 55 77).

Reports of dead wild birds to the GB helpline (or online reporting system), administered by Defra on behalf of all three GB administrations, are triaged by APHA^[7]. Wild bird carcasses meeting the criteria for testing are collected, where logistically feasible, by APHA’s contractor. Not all birds are collected for testing.

Carcasses identified for collection are picked up by courier and delivered to the nearest Scotland’s Rural College (SRUC) veterinary laboratory for identification, and sample collection, with swab samples taken and sent to the APHA NRL (Weybridge) for testing. In all cases cloacal and oro-pharyngeal swabs are collected from a maximum of three birds per case per species (both for target and non-target species). Differential diagnosis investigations are also undertaken by SRUC where relevant.

In some instances, nature reserve staff (who have been trained to take swab samples from dead birds in the field), in consultation with APHA and NatureScot, send samples directly to the APHA NRL (Weybridge) as part of the dead wild bird surveillance. Wild birds and mammals may also be submitted by SRUC as part of wider Diseases of Wildlife Surveillance under their contracts with the Scottish Government.

Surveillance allows the Scottish Government to understand the levels of risk to poultry, other captive birds and public health, and what relevant mitigation measures may be adopted commensurate to the level of risk. It is not designed to help understand how the disease impacts wild bird populations from a conservation perspective.

APHA keeps the thresholds for reporting and triage criteria for testing under review with any changes to the criteria for which birds are collected (species, number, locations) agreed by the ADPG and then published online^[8]. Thresholds can change throughout the year, depending on the risk of incursion to increase or decrease sensitivity of the surveillance as required. Reports to the helpline and online reporting service are triaged against these criteria.

Visit the Scottish Government website for the most up to date reporting threshold. APHA provides an interactive map of wild bird findings in GB: APHA Surveillance for Avian Influenza in Wild Birds and Wild Mammals in GB.

5.1. High Pathogenicity Avian influenza in non-avian wildlife

While HPAI is predominantly considered a pathogen of birds, the virus has been shown in some instances to spillover and cause infection in mammals. In such cases, the virus is termed “influenza of avian origin”.

Where appropriate, and in accordance with set criteria, a number of wild mammals are tested for influenza of avian origin by APHA NRL (Weybridge).

Influenza of avian origin is a notifiable disease in both kept and wild mammals. A case definition for influenza of avian origin together with further information on how APHA monitor the risk of influenza of avian origin in wild mammals has been published to support decision around reporting suspicion.

Causes of death of wild seals and cetaceans are also monitored and investigated in Scotland by the Scottish Marine Animal Stranding Scheme (SMASS), who report suspicion of influenza of avian origin to APHA where relevant.

For any species of dead animal, the advice to the public is not to touch or pick it up. Carcasses may present health risks and are best left alone. If the animal found dead is a carnivora (e.g. fox, otter, stoat, weasel, pine marten, pole cat or badger) and HPAI is suspected, the location of the dead animal should be noted and the local APHA area office contacted for advice. For dead seals or cetaceans these should be reported to SMASS at reports@strandings.org. Further information on reporting marine mammals is available at: www.strandings.org/report. (see section on Advice for Wildlife Rescue/Rehabilitation Centres).

Separate advice is available on the Sottish Government web pages for those encountering sick wild birds or dead wild birds suspected as having been a victim of wildlife crime.