Avian influenza: Surveillance Zone, near Tain, Highland
Declaration of Infected Premises and Surveillance Zone, near Tain, Highland.
Risk assessment: infected premises near Tain, Highland
A 3km Surveillance Zone (SZ) was declared, taking effect from 21 January 2023. This followed a risk assessment of the infected premises by the Animal and Plant Health Agency (APHA). This is below.
Rapid risk assessment: summary
There are no registered premises within 3km of this infected premises (IP). One visitor to the premises has been identified and a high priority tracing has been initiated. Due to the lack of biosecurity on the IP there is a risk of direct and indirect transmission from kept birds to wild birds; however the background risk from wild birds is very high and so the additional risk to poultry posed by this IP is assessed to be very low.
The IP is a hobby backyard flock, located in the North East of Scotland, in very close proximity to the Nigg Bay RSPB reserve and the Cromarty Firth. Prior to suspicion of notifiable avian disease there were 58 birds, comprised of 4 geese, 1 swan, 39 ducks, 9 hens and 1 cockerel and 4 turkeys.
A turkey died on 17 January 2023. On 18 January 2023, two turkeys, and two hens died; a swan was ataxic with nasal discharge and died later that day. The birds were kept in their housing after initial suspicion. A visit was carried out by APHA on 20 January 2023, notifiable avian disease could not be ruled out, and samples were taken. The Deputy Chief Veterinary Officer (DCVO) for Scotland confirmed HPAI H5N1 on 21 January 2023.
The keeper reports that one turkey died on 15 January 2023, but at the time they thought it had been pecked and bullied, and therefore disease was not suspected.
The hazard being assessed is highly pathogenic avian influenza H5N1.
Question: what is the likelihood of spread from this IP (AIV 2023/09) to other establishments with poultry within 1km, 3km and 10km, compared to the background level of risk in wild birds?
This risk assessment will be used to support decisions around derogating from requirements to implement a 3km Protection Zone and a 10km Surveillance Zone.
The investigation is on-going, but given the abundance of wild birds in the area, and the fact that the birds could range freely during the day, direct or indirect contact with wild birds is a likely source. A person visited the premises during the high risk source window to feed the pigs, they also keep poultry and so could have also been a possible source; tracings activities have been initiated to investigate this further.
This section considers the potential risk of spread from the affected establishment to other poultry premises.
According to the APHA SAM database there are no registered premises with poultry within 3km of the infected premises. There are 17 premises between 3km and 10km away, 8 of which have less than 50 birds. There is no requirement for premises with less than 50 birds to register, so it is possible that premises do exist in the area that are not registered.
Routes of transmission for the spread of HPAI from this IP
Direct or indirect contact with wild birds
- kept birds were allowed to free range during the day and were housed at night, after onset of clinical signs when they were kept in
- minimal biosecurity prior to the visit by APHA and housing has large open voids through which wild birds could enter
- fed under cover which will make site somewhat less attractive to wild birds
- high wild bird abundance in the area
Due to the limited biosecurity there is a high risk of transmission to wild birds; however, the background risk in wild birds is very high.
Given the abundance of wild birds in the area, this IP does not pose a significant additional risk to wild birds. The additional risk to poultry as a result of this IP is very low .
Movement of personnel
- one person visited the premises within the high risk spread window, they keep poultry at home and will be visited as a high risk tracing. The person visited the pigs on site, but did not visit the poultry
- limited biosecurity so scope for environmental contamination and indirect transmission back to that person’s poultry at home
Medium risk of transmission, but will be visited as a high risk tracing, therefore mitigations are in place.
Direct movements of birds or products
- none in the last 15 days
- no eggs given away since 2020 and birds were off-lay since October 2022
- no recent disposal of animal by-products such as carcases and manure – nothing within last 30 days
Equipment shared with other properties
- no equipment shared with other properties
Other mammalian species
the owner keeps pigs, sheep, deer and goats
there have been no moves off of these species
the pigs will be sampled. Indirect transmission between poultry and pigs is possible given the limited biosecurity
direct contact between poultry and pigs seems unlikely from the description of the housing and range arrangements
Direct risk of spread from mammalian species on the IP to poultry is negligible.
Indirect contact is possible from the pigs to poultry via the person who visited the pigs. This risk is considered low to medium but uncertainty is high as it is not known if the pigs are infected. Tracings have been initiated to investigate this further.
Birds were allowed to roam outside during the day and were housed at night prior to suspicion of notifiable avian disease; biosecurity was very limited. The housing had large voids through which wild birds could enter and so there was a high risk of direct and indirect contact with wild birds.
The premises is in close proximity to the Nigg Bay Nature Reserve at which there is a large abundance of wild, waterfowl and the keeper at the IP reports that there are a lot of wild geese flying overhead.
One person has visited the premises, they did not enter the area with poultry, but there is scope for indirect contamination as a result of environmental contamination. A high-risk tracing has been initiated.
The national risk level for HPAI H5N1 in wilds birds is currently very high, so although there is scope for transmission to wild birds the additional risk to poultry in 1km, 3km and 10km is assessed as being very low.
There is a problem
Thanks for your feedback