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Submission to the Temporary Committee on Foot and Mouth Disease

R P Kitching National Centre for Foreign Animal Disease

Relevant Dates:

The predictions presented by Prof Roy Anderson, in my opinion, heavily influenced the decision to move policy decisions for the management of the outbreak from MAFF to the Science Committee which directly advised COBR. However the calendar of events listed above would indicate that the outbreak was being brought under control before the introduction of the policy recommended by the Science Committee, in particular the 48hr deadline for the contiguous cull. This policy initially required a cull of premises within 3 km of infected premises and was never fully implemented - later it was acknowledged that "the epidemic appeared to be decreasing more quickly in Devon than in areas where the implementation of the contiguous cull had been more effective." (Minutes of the 16th meeting of the FMD official Science Group: 2nd May)

The early predictive models produced were deficient in a number of input parameters, in particular:

Following implementation of the policy recommended by the models, all infected premises were required to be slaughtered within 24 hours, and contiguous premises, initially up to a radius of 3 Km from the infected premise, within 48 hours. There was no opportunity for those responsible in the affected areas to use discretion, based on local knowledge or previous experience. Diagnosis was on clinical evidence without laboratory support, and whereas this was acceptable for cattle and pigs, this clinical evidence without laboratory support, and whereas this was acceptable for cattle and pigs, this was not possible for sheep.

On 1st May, I asked for a summary of results generated at Pirbright; of 1876 premises that had been slaughtered, classified as VDR, DCF and SOS, samples from 52.76% were negative on laboratory tests. This was reported to the Science Committee on 2nd May.

On numerous occasions during meetings of the Science Committee, both myself and Dr Alex Donaldson expressed concern about the validity of the policy derived from the models. This was also transmitted in a minute to Minister Spellar by Mr Richard Kornicki on 16th April, for submission to COBR.

The implementation of the rapid cull also prevented any detailed epidemiological investigations, and sometimes even the collection of any samples form and "infected premises" - a concern expresses on the 6th April by the HQ Epidemiology Team.

At no time was the diagnostic capability of IAH overloaded, although we did state that it was not necessary to submit large numbers of samples from each of the suspect farms. Because of the difficulty in making a clinical diagnosis in sheep, and because of the probability than the FMD virus had been present in a suspect flock for sometime, I queried the necessity of using the 24 hour cull policy, as there would be no disadvantage to waiting for laboratory confirmation. A blood sample from a suspect infected sheep would be either virus positive or antibody positive, sometimes both - this advice was ignored. Later the question was raised that the sensitivity of the tests being used at Pirbright was not sufficient to identify al infected animals. In my opinion, samples collected, following recommended procedures, from infected animals in an unvaccinated population , would be close to 100% sensitive.

The consequence of adopting the policy recommended by the models was:

Public perception of control programme both in the UK and abroad was severely damaged

Conclusion.

In my opinion, MAFF were bringing the 2001 FMD outbreak in the UK under control before any of the policy changes recommended by the Science Committee were implemented and that while predictive models can be a useful tool in helping to formulate an epidemic disease control policy the takeover of the programme from MAFF by the Science committee, which was heavily influenced by the modellers with very limited practical experience of FMD, resulted in the unnecessary slaughter of possibly as many as 2 million animals.

In my opinion, most of the spread of the FMD virus occurred before the imposition of the movement ban on 23rd Feb, but because this was in sheep and clinically not obvious, it was not seen. Therefore, new cases were not added to the daily total, until the virus spread into cattle, often on the same farm, or had cycled a number of times in the sheep flock. This concept was presented to the Science Committee in April as an alternative interpretation to the models being used, one that did account for the observation that apparent new introductions were occurring after the movement ban (Fig 1) My proposal was considered unlikely by the modellers.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 

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