I promised to keep the House informed of matters relating to the FMD outbreak. An incident has occurred at the Merial facility on the Pirbright site. While the incident was contained, I thought it right to report the matter given the understandable public interest in this site.
On 6 November, DEFRA restored the Specified Animal Pathogens Order (SAPO) licence to Merial Animal Health to permit the use of FMD and Bluetongue viruses for vaccine production. The licence was restored following detailed DEFRA and HSE inspections that confirmed that the terms of the licence (including operating procedures and installation of security measures) had been fully met and that it was safe for vaccine production to recommence.
The licence requires several layers of biosecurity to be in place. This includes first, a new facility which has been installed to heat treat waste from virus production. Secondly it requires the re-lining, sealing and testing of the effluent pipes and man hole covers as identified in the HSE and Spratt reports. Thirdly, the ground above the drains has been made a contained area and all movements across it controlled with decontamination required of any one who has need to enter that area. Lastly all effluent passes into the chemical treatment facility, which as the final layer of biosecurity would deactivate any live virus. It is monitored and tested daily.
All of these measures provide several independent layers of safety and ensure that the process is contained.
On Monday 19 November Merial discovered a shortfall in the quantity of virus recovered from production batches from the previous week. On inspection of the vaccine production equipment they identified possible technical problems with the functioning of a valve on a pipe leading from the centrifuge which is used to separate live virus from waste product. Operations were immediately stopped and the machine and associated pipework were decontaminated with steam. Citric acid was added in bulk to the effluent sump to disinfect any live virus that might have leaked out of the centrifuge.
Having been contacted on Monday, an engineer examined the machine on the morning of Tuesday 20 November. No problems were identified with the centrifuge, and investigations focussed on a valve on a steam line used to sterilise the associated pipework. This valve separates the live virus product line from the line which provides an outlet for the condensate from the steam cleaning stages. This water should not come in contact with live virus, but as a precaution does enter the contained drainage system leading to the final chemical treatment facility. As part of the SAPO licence, we require Merial to apply rigorous standard operating procedures. In relation to the valves these mean that each time the centrifuge is used two operators must certify that the valve is locked shut and its integrity is confirmed by pressure tests before and after each batch. In addition the preventive maintenance system includes regular inspections and although the valves on the centrifuge have a three-year life expectancy they are replaced annually. All these checks must be recorded.
Despite these measures Merial judged that the valve had been leaking, allowing an unintended probable release of live FMD virus into the contained drainage system, which was then pumped to the final chemical treatment facility without being heat treated.
During the course of Tuesday 20 November Merial arranged for the valve to be replaced and tested the centrifuge to ensure that it was now working properly. Merial informed DEFRA officials at 4pm of this incident and of the action that they had taken. Having learned of this possible breach of a SAPO licence condition, DEFRA suspended Merial’s SAPO licence with immediate effect.
A joint DEFRA, HSE and Veterinary Medicine Directorate inspection team visited the site yesterday morning. They confirmed that all work with live virus had stopped, they confirmed the details of the incident that Merial had reported, and carried out detailed inspection, including of record keeping.
The inspection team judge that while it was possible that live FMD virus had entered the contained drainage system, from their discussions and the evidence gathered they are assured that live virus has not been released to the environment. The extensive layers of biosecurity that we require under the SAPO licence effectively contained the virus in the closed, re-lined drainage system before deactivation in the chemical treatment facility.
The SAPO licence remains suspended and the inspection team will produce a full report to the acting chief veterinary officer. We will then consider what further action needs to be taken.
I will report further to the House in due course.