1 Diagnostic capacity in Europe and position on utilization of PCR based

In summary, the situation had been difficult and latterly made even more so by the arrival of bluetongue (BT). There were significant lessons to be learned from the event and from the use of additional surveillance operations, that have implications for future epidemic management. Surveillance sampling had proved negative, except in the discovery of IP5 (sheep). This IP appeared to be crucial to the understanding of the second cluster. In his presentation, David Paton reviewed the use of lab procedures in the surveillance for FMD and the insights from molecular analyses. During the August-September period, staff had visited 18 holdings for FMD examinations including aging of lesions, tested samples by antigen ELISA/rtRTPCR from 54 suspected FMD cases (~ 3,500 samples) and performed serology on circa 19,000 blood samples. Results were provided through a secure web-based portal to DEFRA. Virus isolation was used selectively, reducing workload; “pen-side tests” - lateral flow devices (LFD) – were evaluated at the lab and on farm and indicated significant promise as a screening test with similar sensitivity to antigen detection ELISA. Serological procedures used the SPCE-O & Cedi-O for serological screening and CediNS and VNT for confirmation. Probang testing was applied on three holdings. He highlighted: 1) the effort placed on preclinical diagnosis, with rtRT-PCR screening of ~1,800 samples, this had detected on IP (2c); 2) the assistance to outbreak tracing provided by full length sequencing of outbreak and related viruses; the results provided in some cases alternative explanations for the transmission between farms. In particular results suggested IP5, the “link” between the two clusters at Normandy and Egham, originated from the first infected IPs and not from the Pirbright Laboratory complex. No support for this was obtained by tracing, but the molecular evidence was considered conclusive; 3) the use of enhanced surveillance procedures for detection of infection in 14 high risk beef cattle herds, which were subjected to pre-clinical diagnostic test procedures every 2 days. Although this did not result in detection of new cases, it provided confidence for their absence.

He concluded that a number of questions remain, including: - the mechanisms of escape of virus and the entry of virus to the first IP; - how infection spread from Normandy to Egham; - the possible role of airborne transmission between some of the IPs; - duration of virus survival in soil.

He posited that the experience brought into question: - the size of 3 km and 10 km zones; - the impact of immediate use of vaccination; - how wildlife could be included in a surveillance scheme; - the risks (fire, flood, etc) to the function and availability of National FMD reference laboratories – should there be planning for emergency cover by most European labs?

Discussion

The main issues discussed were:

• fragmentation of herds/holdings; definition, control measures to be applied; • size of surveillance zones; • improving the reliability of owner observation and veterinary surveillance for detection of FMD in cattle.

On the first, the degree of separate management of the parts of a herd/holding was discussed. To count as a separate part then records must clearly indicate when animals move between the parts. Common ownership or management practises that involve fomites or personnel transfer between parts should mean each part is treated as dangerous contacts. The degree of management separation is to some extent variable but guidance may assist to assign parts as separate. Size of the surveillance zones - Dr Alf Füssel reiterated that the Directive does not restrict member states to the size of the zones and wider surveillance can be applied when the particular risk features are recognized; Dr Aldo Dekker suggested this is left to MS to decide as each increase in a SZ has implications for resources to inspect the farms at risk.