Chaaracteristics of Foot and Mouth Disease Virus in Taiwan.

Abstract

ABSTRACT. Since March 1997 two strains of foot and mouth disease (FMD) virus have found their way into Taiwan, causing severe outbreaks in pigs and in Chinese yellow cattle. Outbreaks occurred in March 1997 were caused by a pig-adapted virus strain (O/Taiwan/ 97) which did not infect other species of cloven-hoofed animals by natural route. The epidemic spread over the whole region of Taiwan within two months and the aftermath was 6,147 pig farms infected and 3,850,746 pigs destroyed. In June 1999, the second strain of FMD virus (O/Taiwan/99) was isolated from the Chinese yellow cattle in the Kinmen Prefecture and in the western part of Taiwan. By the end of 1999, Chinese yellow cattle were the only species infected and those infected cattle did not develop pathological lesions. Seroconversions of serum neutralization antibody and on non-structural protein (NSP) antibodies were the best indicators for infection in non-vaccinated herds. The infected animals, however, excreted infectious levels of virus to infect new hosts. Based on the detection of the specific antibody to FMD virus, and virus isolation from oesophageal-pharyngeal (OP) fluid samples, ten herds of Chinese yellow cattle located in Kinmen and Taiwan were declared to have been infected. During the period of January to March 2000, however, five outbreaks caused by FMD virus similar to the O/Taiwan/99 virus occurred in four prefectures of Taiwan. The infected species included goats, Chinese yellow cattle and dairy cattle. Those outbreaks have caused high mortality in goat kids under two weeks old and also developed typical clinical signs of infection in dairy cattle.KEY WORDS: Chinese yellow cattle, foot and mouth disease virus, non-structural protein, serotype O, VP1 gene.

Foot-and-Mouth Disease

“…The role of the 3A protein in viral virulence was demonstrated during studies of the FMDV isolate responsible for an outbreak in Taiwan in 1997 (designated O/Taw/97) (see below). This outbreak was unusual in that only pigs, and not cattle, were affected, and the disease had an unusually high mortality rate in pigs (143,216). Molecular characterization of the virus revealed that it contained a 10-codon deletion in the C-terminal half of the 3A protein (47).…”

Molecular Epidemiological Investigation of Foot-and-Mouth Disease Virus in Korea in 2000.

“…It was suggested that subclinically infected sheep were a major risk factor in the transmission and spread of FMD both within and between countries during the pandemic. It was suggested that the origin of the Pan Asia strain of ME-SA topotype which caused recent FMD outbreaks in Taiwan, Japan, and Mongolia would be viruses circulated in Mainland China [4,5,11,14]. It was believed that there was widespread FMD in China such as Beijing, Shenyang, Jilin, and Heilongjiang Provinces during the winter season from 1999 to 2000.…”

Decline ofSalmonella entericaSerotype Choleraesuis Infections, Taiwan

“…According to an inspection program conducted by the Council of Agriculture in 2004, illegal slaughter of pigs dying of unidentified diseases and sale of the pork at a reduced price were common in Taiwan and probably were associated with transmission of the organism ( 4 ). In Taiwan during 1996–1997, a large epidemic of swine foot-and-mouth disease occurred ( 5 ), and consumption of pork decreased substantially. To prevent further spread of that epidemic, the government implemented massive slaughter of infected pigs and a swine vaccination policy ( 5 ).…”

“…In Taiwan during 1996–1997, a large epidemic of swine foot-and-mouth disease occurred ( 5 ), and consumption of pork decreased substantially. To prevent further spread of that epidemic, the government implemented massive slaughter of infected pigs and a swine vaccination policy ( 5 ). Coincidently, in 1996–1998, S. enterica Choleraesuis infections among humans decreased significantly (p<0.001) ( 2 ).…”