Open session of the standing technical committee of the EUFMD- 2000

4 Dr. K. Sakamoto presented results of studies on the virulence of O/Jpn/2000 for susceptible animals (Appendix 2). Japanese Black beef cattle as well as Holsteins were infected experimentally using this isolate. There were only mild clinical signs in Japanese Black beef cattle and no clinical signs (and no virus excretion) in the Holsteins after inoculation of 106TCID50. However, pigs developed typical clinical signs after experimental inoculation. Virus was detected in all experiments by RT PCR. The origin of the virus is still unclear but it was speculated by the authors that straw bedding (and maybe fodder) imported from China could have been the source of introduction. The vaccine which was supplied to Japan (4 million doses) was not used.

Mr. N. Knowles also presented a further paper on the origin of recent outbreaks of FMD in North Africa, the Middle East and Europe (Appendix 3). The origin of recent outbreaks of FMD in these countries were examined using phylogenetic analyses. The 1999 outbreaks of Type O in Algeria, Tunisia and Morocco originated in West Africa. In Iran and Turkey most type A viruses belonged to either the Iran-96 or Iran-99 lineages, however, a new strain was found in eastern Iran which was related to viruses present in India. The type Asia 1 outbreaks in Greece in 2000 were closely related to viruses from Turkey, Iran and India.

Dr. I. Gürhan gave an update on the FMD situation in Turkey (Appendix 4). A total of 90 outbreaks were recorded from 1.1.00 to 31.8.00. The viruses found were of serotype Asia1 (46), serotype O (39) and A (4). The last Asia 1 outbreaks occurred in August. A total of 9 samples were in addition submitted to the WRL and confirmed.

The serotype A is closely related to A Iran 96. The FMD institute has produced monovalent, bivalent as well as trivalent vaccine. The latter is used at present (A Aydin 98, O1 Manisa, Asia 1). In the spring vaccination campaign 6.3 million cattle and 3.2 million small ruminants were vaccinated in the whole of Turkey. The autumn vaccination campaign is to start on 15 September in Thrace. It will include the Thrace provinces as well as the Anatolian part of Istanbul and of the Canakale provinces. All ruminants (including sheep and goats) will be included. A total of 1.5 million doses of the trivalent vaccine A22 + O1 Manisa + Asia 1 have been supplied by the EU vaccine bank which arrived on 6 September. In Anatolia only large ruminants will be vaccinated using the trivalent vaccine A Aydin 98 + O1 Manisa + Asia 1 produced in Turkey. Some remote areas of the Black Sea region will not be vaccinated since no outbreaks have been reported for the past couple of years.

In the next paper (Appendix 5) Dr. S. Alexandersen examined the 50% minimal infectious dose (MID50) of airborne FMD virus for pigs using infected donor pigs as the source of infection. So far data have been generated for O1 Lausanne FMDV. The MID50 was estimated to be around 200-400 for subclinical infection (only antibody reaction) while the estimated MID50 for causing clinical disease was more than 800 TCID50. Doses around 100 TCID50 did not cause any infection and doses as low as 10-15 TCID50 or less, known to infect ruminants did not infect pigs by the aerosol route.

Dr. A.R. Samuel presented a paper on the antigenic and genetic characterization of FMDV type O virus from the Far East (Appendix 6). FMD type O viruses isolated from outbreaks in Cambodia, Vietnam and Taiwan, Province of China in 1997 and 1998 were examined both genetically and antigenetically. Phylogenetic