By Charles Milne, spokesman for AIMS, former chief veterinary officer, Scotland
The upsurge of Highly Pathogenic Avian Influenza (HPAI) in wild birds and Defra’s announcement of the requirement to house birds in the north of England from 30 October 2025 provide a timely reminder of the risk for the poultry industry from this devastating disease. HPAI has significant economic consequences for producers, processors and ultimately consumers many of whom rely on poultry as an affordable source of protein. The risk to human health with this disease is illustrated by providing the route cause of human pandemics in the past. Indeed, the Department of Health is to run a scenario based contingency exercise later this year using an influenza outbreak with an AI source in the narrative.
Vaccination could provide a powerful tool to combat AI in the future and the reduction of incidents in China following a vaccination campaign provides evidence to support this approach. Several obstacles will need to be overcome to permit routine vaccination including managing the impact on trade, the development of testing to differentiate between infected and vaccinated animals and also an understanding of whether vaccines protect against disease or infection and their impact on genetic drift which could have implications for human health.
However, in the meantime as with many diseases a few simple precautions can significantly reduce the risk of infection entering a flock. These are neither expensive or time consuming to implement and should be embedded within normal management practice. Whilst this is not rocket science, and many individuals will have taken effective action already, it is useful to reiterate some of the key points at this time of heightened risk.
As wild birds contaminate the environment infection can be introduced to housing through dirty boots and clothing. Regular cleaning reduces this risk and providing disinfection points at the entry of buildings, which should be used every time the building is entered, is a must. It is also essential to regularly replace the disinfectant as it is deactivated by use. This is particularly important for off-site personnel including catching teams. As these staff are moving between premises they present a serious risk of disease transfer. Clean clothing on every site is essential as well as scrupulous disinfection of clothes and equipment. Any dirty clothing or equipment must not be permitted to enter the premises.
Another common route of introduction to a premises is through contaminated vehicles. Where possible vehicles should not enter the perimeter of a site but on the occasions where this is necessary vehicles must be clean and wheel arches etc disinfected on entry. Dirty vehicles should be turned away.
The same principle applies to equipment used between houses or between premises. This should be reduced as much as possible but if necessary strict cleaning and disinfection regimes are required. Effective cleaning of clothes and equipment is important before disinfection as an excess of dirt prevents the penetration of the disinfectant and as mentioned above, also deactivates the disinfectant.
AIMS will continue to monitor the incidence of HPAI and update members on significant developments. We will also lobby government on your behalf to ensure that measures taken to control the disease are appropriate and do not impose unnecessary burdens on the poultry industry.