口蹄疫ウイルスと口蹄疫の病性について

（農林水産省家畜衛生試験場ウイルス病研究部病原ウイルス研究室長）

Foot-and-Mouth Disease Virus and the Disease Nature by the Virus

Yosuke MURAKAMI

National Institute of Animal Health, Tsukuba, Ibaraki 305-0856, Japan   Foot-and-mouth disease (FMD) affects all cloven-hoofed animals and is considered the most infectious of all animal diseases. It is endemic in many countries of the world, including Africa, Asia and parts of South America, where its importance relates to not only to the reduced productivity of livestock, but to the restrictions placed on the international trade of animals and their products. The causative agent, FMD virus which classified genus aphthovirus of the Family Picornaviridae, has seven serotypes, designated as types O, A, C, SAT (South African teritorries) 1, SAT2, SAT3 and Asia1. The infection with any serotypes does not conferred immunity against another serotypes. Antigenic variation is also observed even in the same serotypes, which had been designated by subtypes until the late 1980ﾕs. In addition, the infection has many difficult aspects to be controlled when compared with the other animal diseases. In March 1997, a large scale epidemics of FMD occurred in Republic of China, Taiwan. The outbreaks forced to have a large socio-economic impact to the country which came from loss of over four million pigs and lost international pork markets, specially for Japan. Japan, free from FMD nearly for a century, is a major country to import animals and animal products of the world, while a considerable population of livestock has been maintained inside of the country. Besides, the trade in animals and animal products has greatly expanded under the World Trade Organization rules. These situation forces to have a continuous threat from the invasion of FMD to Japanese animal husbandry than before.   Therefore, it is essential to have the correct comprehension on the disease nature of FMD for the prevention from the invasion. This article reviews the present situation of FMD in the world, virology, epidemiology, diagnosis, immunoprophylaxis and disease control measurements of the disease. 山口獣医学雑誌　第24号　1〜26頁　1997（Yamaguchi J. Vet Med., No. 24: 1〜26．1997）より転載