Issue 152

A Crash Course in... Bird Flu

12th February 2007

Avian influenza, or Bird flu, has been confirmed in the UK, and as a direct result a large number of turkeys have recently had to be slaughtered. But what exactly is bird flu, and what is the danger – if any – to human health?

Bird flu originates from East Asia, is extremely infectious for all forms of bird and is usually fatal to its avian host. Whilst it is extremely infectious from bird to bird, cases of the virus travelling from bird to human are rare, although it has happened on rare occasions.

Transition from bird to human can happen through prolonged exposure to the infected animal, which has happened in the cramped and squalid conditions of the East Asian slums. Should it manage to get into the body, it has a high mortality rate of 61%, although crucially, it cannot spread from human to human. This enables the virus to be contained – for the moment. So far, it is believed that 165 people have died as a result of contracting the virus from birds.

The great danger is that the virus may get into a human already infected with the human influenza virus and mutate into a new virus that can be transmitted from human to human. This would not normally occur except for in the weak, elderly or infirm.

Should the Avian flu virus infect an individual who already has the flu, there is a distinct possibility that it may mutate into a hybrid version – with the contagious threat of human flu and the high mortality rates of Bird flu. Should this happen, the hybrid version of the virus would be able to spread globally at a very fast rate, mostly thanks to international air travel. The biggest difficulty with this is that until a sample of the hybrid virus is contained and examined by the scientific community, it is impossible to develop an antivirus because the exact form of the virus cannot be predicted. Unless an antibody could be produced quickly and distributed globally, tens of thousands could be killed.

The odds of such a calamity befalling the UK, however, are low. Once an antibody was developed in sufficient quantities it would be logistically possible to ensure 100% immunisation of the population; there is therefore a correspondingly low threat to human health in the UK.

3rd world countries, however, stand to suffer the most. The greatest threat to the UK, is the economic impact. The contamination of the domestic poultry market by bird flu places a black mark on the confidence that any customer may have. The record of the government in containing large scale diseases in agricultural livestock is poor – the foot and mouth debacle proved as much, and dealt a correspondingly large blow to the UK's cattle market. It is entirely possible that the recent outbreak of bird flu may have a similar effect upon the poultry market.

Dan Shaw