Originally from: MediaVets
                        
I have come by some information about the results of the serological testing to lift Protection Zones.

At the point of reporting 5.640 flocks had been tested.

Of these 29 had one or more 'non-negative' results with the primary screening ELISA test.

Of these 29, 17 had a single animal with a positive ELISA result and 16 of these 17 were found to be negative when re-sampled and re-tested.

The remaining 13 flocks had positive results which were confirmed on further serological testing, suggesting that FMD infection had been present in the past.

These 13 flocks were culled and testing at slaughter for the presence of virus confirmed current FMD infection in one flock in Devon. Serosurveillance of surrounding flocks showed no evidence of past infection.

The 'breakdown' of seropostive flocks was as follows:

England
Devon 6
Kent 1
Northumberland 2
North Yorkshire 1

Wales
Gwynedd 1
Powys 2

Total 13

 From these data the current estimate of prevalence of seropositive flocks in Protection Zones is 0.23%, with a likely minimum and maximum prevalence of 0.11% to 0.36% (95% confidence interval).

Each filed disease centre has a quota for surveillance serology.

Serosurveillance is working from Protection Zones on the margins of Infected Areas towards the centres – so as to allow an orderly shrinkage of the Infected Areas.

Lab capacity for surveillance testing was at the time of reporting about 80,000 samples a week and should be 100,000 samples per week by the end of July (this is in addition to diagnostic serology).

Regards

Andrew

Andrew Stephens BVetMed MRCVS