Bird Flu, Risk Communication and the Media

Headlines associated with bird flu (Avian Influenza) have been with us for over 2 years and look set to remain. How the media report developments could have a major impact on the poultry and food manufacturing industry in Wales and the UK.

The current problems with the H5 N1* strain of highly pathogenic Avian Influenza (A/H5 N1) probably started in the 1990’s in China, but was first reported in 1997 in Hong Kong killing 6 people. Typically the H5 N1 strain does not infect humans, although close contact with poultry has enabled humans to acquire it and become infected. The strain re-emerged again in 2003 with reports first from Hong Kong and then Korea. Subsequently the virus has spread much further in the bird population with reports across Europe and 1 reported dead swan in Scotland. Human cases and deaths have still mainly been reported in South East Asia with Turkey being the nearest country to the UK to have had a human infected. Transmission to humans is relatively rare, and spread from birds has required close contact.

Crucial is how the media report events surrounding developments relating to avian flu. Unfortunately part of the media likes good headlines and best of all good “scare stories”. Currently the virus primarily infects birds and there is a need to ensure that consumers are alerted but not unnecessarily alarmed whilst the media accurately report global developments. The “what if” scenarios about human illness need to be discussed sensibly. Certainly to date there is no indication of any transmission involving consumption of poultry / eggs which, for other reasons, should always be well cooked. Also, with the spread of H5 N1 strain, passage from bird to human is difficult and requires close contact with infected birds, passage from human to human does not seem to occur. However, this can change if the virus mutates or combines with a human flu strain the former known as antigenic drift, the latter as antigenic shift.

People working within the poultry industry also have a very important role to play and this can be considered in 3 parts:

• prevent their flocks becoming infected
• protect staff working in the industry
• both of the above will help to reduce the likelihood of a more pathogenic human strain developing

Biosecurity controls help to minimise the flocks becoming infected. Most commercial flocks are raised in enclosed housing. These controls should prevent the virus gaining access to poultry and cover proper cleaning and disinfection. This means not only using disinfectants that kill the virus but ensuring they have time to work and the cleaning is carried out properly, no use of high pressure jets (spread contamination) and the use of clean equipment and materials. Controlling what moves in and out is important and includes air, water, feed, equipment, pests and people. The virus can survive for days and migrating birds carrying the virus can cause extensive spread. Anything that can enter or exit poultry houses can spread the virus and security should be at both farm level (e.g. decontaminating vehicle tyres/wheels) and at the individual house level. Disinfectants in foot baths should be changed frequently as the disinfectant can become saturated with soil / other debris, which can reduce its efficacy. The use of disposable overshoes is also a good idea. Other protective clothing should be worn and cleaned carefully and hand hygiene is also very important.

Breeding free range birds is more problematic as these can be exposed to infection from wild birds but awareness of local / national developments, careful surveillance to identify rapidly potentially infected birds, coupled with back up facilities for housing birds inside, if necessary, are all important. All breeders should cooperate with local vets and government organisations and be prepared to act quickly if infection occurs. This, coupled with slaughter of infected animals, will help to limit the spread of the virus. If this does happen, people must not just look at “high tech” solutions based on antiviral drugs and vaccines but remember the rules of good basic hygiene. It has been estimated that up to 40% of colds and flu may be spread via hand contact with contaminated surfaces.