6 6. Taq Man PCR technique is a valuable tool for quantitative studies on FMD. It shows promise for the diagnosis of FMDV. 7. Detection of the mucosal IgA response to FMDV is an additional method to detect carrier cattle and cattle exposed to infectious virus. 8. The FMD situation in Turkey is still of concern since a large number of outbreaks have been reported throughout the year 2000 in Anatolia. At present 3 FMDV serotypes (O, A and Asia 1) are circulating in Turkey. Recommendations: 1. Further analysis of known antigenic sites in terms of sequence should be done as valuable support to serological testing. 2. The minimal aerosol infective doses of FMDV for pigs (using pig adapted strains) should be determined to improve models to predict airborne spread. 3. Quantitative studies in livestock species of the pathogenesis of FMDV should be performed to formulate equations to describe the kinetics of infection. 4. Virus specific IgA levels in saliva and nasal swabs in cattle and sheep should be considered as additional parameters for the detection of carrier animals and animals exposed to infectious virus. 5. Continued submission to the WRL of additional outbreak samples from various parts of Turkey and from each of the detected serotypes should be encouraged. Item 3
Control of FMD
In the first presentation under this item (Appendix 10) Dr.A.I. Donaldson reviewed the role of sheep in the epidemiology of FMD and highlighted the main features of virus transmission related to that species. FMD in sheep is often very mild or subclinical and so their infectivity status may not be clear until they transmit the virus to indicator hosts, most commonly cattle. Examples were provided of the numerous occasions when live sheep have been the source of infection in the transboundary spread of FMD. Infected sheep excrete most FMD virus in the early acute stages of infection which usually lasts for 4 to 5 days and so this is when they are most likely to transmit the virus. An important feature of FMD in sheep is that the infection may be self-limiting. This is supported by evidence from both the field and preliminary experimental investigations. It was concluded that there may be certain circumstances when the self limiting infection of sheep can permit different control strategies to be applied. A series of recommended actions and strategies were presented (Table 1, Appendix 11) which aim to achieve particular control and eradication objectives under different circumstances in which sheep are a major component of the livestock population.
