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Seminar 846  
Date:2015-02-11
Update:2015-04-02

Seminar:  846  

1

Speaker(s)

Fan Lee

Topic

From Data to Article12-year Survey on Bovine Ephemeral Fever

Abstract

Bovine ephemeral fever is an arthropod-borne viral disease affecting mainly cattle and buffaloes. Etiological agent of the disease is bovine ephemeral fever virus which is a member of the genus Ephemerovirus within the family Rhabdoviridae. As one of the most important bovine infectious diseases in Taiwan, bovine ephemeral fever has been threatening our bovine population for decades, since its identification in 1967. Routine vaccination against the disease has been implemented; meanwhile, outbreaks still occur almost every year and epizootics every a few years. To monitor the humoral immunity of cattle population, Animal Health Research Institute has conducted national survey programs from more than one decade and a huge number of data have been accumulated. This talk did not intend to present the results of the survey programs. Instead, we attempt to explain how we illustrate the findings, connect the findings with what we believed, and successfully present the findings on a scientific journal.

2

Speaker(s)

Lu-Jen Ting

Topic

Relationships of bovine ephemeral fever epizootics to population immunity and virus variation

Abstract

Bovine ephemeral fever is an arthropod-borne bovine viral disease caused by infection with bovine ephemeral fever virus which belongs to genus Ephemerovirus within the family Rhabdoviridae. In this study, serological data and virological information about the disease and the virus, spanning from 2001 to 2013, were employed to analyze the relationships of bovine ephemeral fever epizootics to population immunity and virus variation. National and regional surveillance data indicated that 2 of the 3 major epizootics and 87% regional outbreaks were associated with lower neutralizing antibody titers and immunity coverage, reflecting the importance of population immunity for the control of bovine ephemeral fever. Phylogenetic analysis and sequence comparison demonstrated that Taiwanese bovine ephemeral fever viruses were >96.0% and >97.6% similar to the East Asian isolates in nucleotide and amino acid sequences, respectively. These analyses supported that the Taiwanese viruses shared the same gene pool with the strains of the other East Asian countries, mainly Japan.

3

Speaker(s)

Shu-Chun Chiu

Topic

Production of the Classical Swine Fever Live Vaccines

Abstract

Hog cholera (HC) or classical swine fever (CSF) is a highly contagious and fatal septic disease caused by a virus belongs to Pestivrus of Flaviviridea family. Severe outbreak had been reported in Taiwan during the period under Japanese occupation. The situation has been put under controlled timely thanks to successful development and widely use of the LPC-China strain live vaccine in 1950s. Therefore, the pig industry of Taiwan has been thriving and robust. In response to the movement of piglets in early age, the government established a vaccination program for piglets depending on the vaccination program of sows. The wild field strains isolated before CSFV 1996 belong to genotype 3, since then the epidemiological analysis of CSFV showed that there had been a switch in virus population in Taiwan. Base on their genomic sequences, LPC strain belongs to genotype 1, whereas the current wild field CSFVs belong to genotype 2. Even so, the antibodies induced by immunization of commercial LPC vaccine in pigs could still provide enough protection against two other genes of CSFV infection. The LPC-China strain seed virus titer is RID50 10 4.5 per dose.  We have produced 311,440 doses of LPC-China strain live vaccine in 2014, with 31 percent market share of Taiwan.

4

Speaker(s)

Chun-Hsien, Tseng

Topic

The Report of Training in OIE Reference Laboratory for rabies, France

Abstract

Ferret badger is the major infection and reservoir animal of ferret badger rabies virus (RABV) of Taiwan. In order to realize the pathogenicity and transmission pathways of RABV in ferret badgers, and to assess the effect of oral vaccine in ferret badgers, we need to set up animal tests for rabies vaccine immunization and challenge test, and establish fluorescent antibody virus neutralization test (FAVN) which is the OIE standard method of serological detection. Therefore, we have visited Nancy laboratory for rabies and wildlife in France, the OIE reference laboratory for rabies, for training. This study divided into two groups, animal experiments and serological tests. In animal experiments, we have learn the diagnosis of sample, fluorescent antibody test (FAT), intracerebral inoculation of mice, administration of oral vaccine and its following challenge test on fox as well as, animal testings of vaccine inspection. In serological part, we have learned FAVN test, cell line subculture, CVS-11 virus propagation and titration, and titration of oral vaccine baits. Through this training abroad, we have not only improved technical skills on the diagnosis of rabies pathogen, animal challenge test and serological test, but also developed good communication channel with France and learned the management and operation of an OIE reference laboratory.