A new risk assessment document ‘PAI H5N1 situation in Europe and potential risk factors for the introduction of the virus to the United Kingdom,’ has been published by Defra, the UK government agency.

The document says that it is highly likely that outbreaks of H5N1 avian influenza will continue to be detected internationally. The UK has measures in place (e.g. import controls, enforcement at the borders, biosecurity measures) to mitigate against the risk of introduction of the virus by a variety of pathways, such as legal and illegal trade.

Experience from the last year shows that there is an increased risk of the introduction of H5N1 to the UK during the wild bird migration season. While this risk is likely to continue during the coming autumn, it is less likely that the virus will move direct to the UK without being detected in the EU first. Any increase in the spread of the virus within the EU will increase the risk to the UK.

It remains uncertain whether the virus will persist in the breeding grounds of wild migratory birds which return to the EU and UK. It is also uncertain exactly how the disease is transmitted within wild bird populations. Furthermore, there are a number of significant variables including bird species and environmental conditions such as the weather. These factors are taken into account when determining the level of the threat to the UK, but a high degree of uncertainty remains over how avian influenza may spread across Europe in the coming months, and therefore what the exact risk to the UK is at this time from migratory birds. There is a constant negligible risk from legal and illegal trade.

This level of uncertainty means that the proportionate national and international surveillance activity in place is important not only as an early warning system, but also to allow detailed analysis of the effectiveness of disease control activity and add to our understanding of the virus. Defra with ornithologists, epidemiologists and other experts are developing detailed migration models to determine areas which have a greater risk of introduction of the virus to the UK.

It remains the case that surveillance and high levels of biosecurity are the most effective way of detecting and preventing the introduction of the virus into poultry. It is important that all bird keepers maintain biosecurity standards and remain vigilant at all times.

Additional biosecurity measures are also available in times of heightened risk should a veterinary risk assessment indicate they are necessary, including restrictions on bird gatherings and housing requirements.

Read ‘PAI H5N1 situation in Europe and potential risk factors for the introduction of the virus to the United Kingdom.’

•Date: 7th July 2006• Region: UK •Type: Article •Topic: Pandemic planning UK
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