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Low Pathogenic Avian Influenza

Volume 461: debated on Tuesday 12 June 2007

My hon. Friend the Minister of State with responsibility for Public Health and I would like to update the House on events since the recent case of low pathogenic avian influenza near Corwen in North Wales. On 17 May, a private veterinary surgeon contacted the Veterinary Laboratories Agency (VLA) in Shrewsbury, as well as Animal Health (formerly the State Veterinary Service) in Caernarfon and Defra, following the deaths of 10 chickens over a number of days on a farm near Corwen. Late that day he sent three chickens to Shrewsbury for testing and samples were then sent to VLA headquarters in Weybridge, Surrey for further tests. This was treated as a routine investigation due to the lack of any suspicion of an avian notifiable disease.

On the morning of 23 May, VLA notified Defra that preliminary results indicated the presence of the H7 strain of avian influenza. Veterinary officers from Caernarfon immediately visited the farm in Corwen and placed restrictions on the premises. Animal Health also began tracing the birds back to Chelford market in Cheshire on 7 May and investigating premises that had also received birds from that day's market.

From the first preliminary notification of H7 avian influenza, it was agreed that a strict public health protocol be applied to limit the exposure of persons to possible infection. Pre-exposure prophylactic antiviral Oseltamivir (otherwise known as Tamiflu) was offered to those who would potentially be exposed during the outbreak investigation and control operations. Immediate treatment was provided to anyone who had been exposed to infected birds since the onset of symptoms of disease. The National Public Health Service for Wales (NPHS Wales) led the public health response in collaboration with the Health Protection Agency (HPA).

That afternoon, the Chief Veterinary Officers for the United Kingdom and for Wales decided that the remaining birds on the premises should be slaughtered on suspicion of avian influenza. Tracing of possible human contacts with birds at the infected premises and through the supplying Chelford market was immediately put in place. By 24 May, seven people were under investigation, having reported flu-like illness and associated with contact with two premises with sick birds. Four of these tested positive for either influenza A or H7 infection. All four were presumed confirmed cases of infection associated with this outbreak and three had been hospitalised and were recovering. Given the serious nature of illness seen in three of the four confirmed cases, and because the possibility of person to person transmission could not be ruled out, a precautionary approach was taken with respect to antiviral prophylaxis. Overall, over 360 people were identified as possible contacts or cases associated with this incident, though only four cases of infection were confirmed. The Food Standards Agency re-stated their advice that there is no risk in eating any sort of properly-cooked poultry or eggs.

On 24 May the VLA confirmed the results as low pathogenic H7N2 avian influenza. The CVO Wales then confirmed disease and the Welsh Assembly Government (WAG) rapidly made an announcement and put their contingency plans into action. The WAG immediately imposed a 1km restricted zone around the infected premises which was judged proportionate for a case of low pathogenic disease.

The CVO UK notified the European Commission and the International Animal Health Organisation. The Department of Health briefed the European Centre for Disease Prevention and Control, alerted the World Health Organisation and disseminated an alert through the EU Early Warning and Response System. Animal Health issued a text alert to all poultry keepers on the Great Britain poultry register and established a Local Disease Control Centre in Caernarfon and a National Disease Control Centre to co-ordinate the response. The WAG also established a Co-ordination Centre to co-ordinate the human and animal health issues in Wales. On 25 May the Cabinet Office convened an official-level meeting of the Civil Contingencies Committee (known as COBR) to ensure cross-Government co-ordination.

By the afternoon of 24 May, Animal Health had completed the humane culling of all remaining birds on the infected premises. Based on expert advice, all bird gatherings involving chickens and ducks were banned in England, Wales and Scotland due to the uncertainties around the movement of those species through Chelford market.

Animal Health has now investigated over 200 tracings and taken samples from birds on all the premises identified apart from one. The majority of those tracings have proved negative and the rest are still awaiting results and are under restrictions. One of those premises, in St Helens, Lancashire, proved positive from low pathogenic H7 on 7 June and almost all the birds involved have been culled and a further 1 km restriction zone placed around those premises.

HPA and NPHS Wales have not found any further confirmed human cases of disease. For these reasons, all bird gatherings were permitted again on 1 June. The HPA and NPHS Wales will continue to actively review any human case of influenza-like illness that might be linked to this incident but tests on suspect cases to date (apart from the original four cases) have all been negative.

The WAG intend to lift the restricted zone around the infected premises in Corwen on 15 June, which is the required period of 21 days following the completion of preliminary cleansing and disinfection.

Once we have completed our tracings and testing, we intend to publish an epidemiological report into the origins of this disease in the next month. We are also conducting a lessons learned exercise which we hope to publish in September. We are committed to learning any lessons.

I would like to take this opportunity to thank our partners both in Wales and those working on human health, as well as Defra, VLA and Animal Health staff, who all worked tirelessly throughout the bank holiday weekend to contain the disease and for a well co-ordinated and successful response.