1

Speaker(s)：

Jen-Chieh Chang, Kwok-Rong Tsai, Yang-Chang Tu, Wei-Cheng Hsu,

Wei-Chieh Chuang, Shu-Hwae Lee

Topic

Pathological findings of porcine reproductive and respiratory syndrome in Taiwan in 2011

Abstract

   The diagnosis reports of swine disease from Animal Disease Diagnostic Center at AHRI in 2011 revealed that the detection rates of PRRS-alone infection was 13% (24/191), PCV2-alone infection was 11% (21/191), and co-infection with PCV2 and PRRSV was 49% (93/191). The cases of PRRS increased obviously in the last two years and PRRS was one of the important pig diseases affected the profit of porcine industry. This study gave a successful model for dealing with PRRS outbreaks in a pig farm situated in northern Taiwan during July to October, 2011. The technical platform of animal health surveillance was applied and clinical pathology, microbiology and molecular biology were performed in the diagnosis and control of PRRS. The pathological examination showed nonsuppurative meningoencephalitis, myocarditis, interstitial pneumonia, interstitial nephritis and mucosal necrosis of the uterus. We also found interstitial pneumonia in the cases of nursery pigs. The producer adopted our recommendation to vaccinate the sows with PRRS vaccine. After vaccination, the abortion cases were getting less in the following 3-4 weeks. The prevalence of sow abortion was about 10% (60/600) and the mortality was 15% (9/60). The nursery pigs showed the clinical signs of weak, thinness, rough hair coat and respiratory syndrome, and the prevalence about 50%. The survival rate decreased from 90% to 60% after the outbreak. After our institute had provided the services of animal diagnosis and health surveillance platform and effectively assisted pig farms in developing early alert system and taking active control strategies, the survival rate resumed 90% of previous performance in October 2011.

2

Speaker(s)：

Chia-yi Chang

Topic

2011 Report on the XV International Congress of Virology in Japan/ Analysis of antigenicity among various subgroups of E2 glycoprotein of CSFV

Abstract

   International Congress of Virology is a prestigious international congress held by International Union of Microbiological Societies (IUMS) every three years. The XV IUMS congress, held in Sapporo, Japan, had 4800 scientists from 65 countries around the globe to participate in. The XV IUMS included 341 oral presentations and 834 posters together with special keynote lectures and Nobel lectures. Through attending IUMS provides an opportunity to dig deeper into research and open new perspectives for the veterinary field and increases the opportunity to cooperate with other countries, help us to deeper understand the conditions of current viral pathogens and help us to understand the current information about viral diseases epidemic situation in the world. The information will be crucial for the government to establish the prevention and control policy and to develop the immunoprotective vaccine to increase the production efficiency and competition ability of swine industry.

   Classical swine fever (CSF) is a highly contagious disease of pigs. Envelope glycoprotein E2 of classical swine fever virus (CSFV) is the major antigen that induces neutralizing antibodies in infected pigs. Antigenicity among various subgroups of E2 glycoprotein of CSFV was analyzed by expression of several truncated E2 proteins of various CSFV strains using baculovirus system and tested for their reactions to a panel of monoclonal antibodies (mAbs) against CSFV. Our study displayed the differences in antigenicity of E2 between various strains of CSFV by their variable reaction patterns between expressed proteins and mAbs. Previous studies revealed that the D/A domains and the C-terminal region were conserved among various CSFVs. However, our results demostrate that the D/A domains and the C-terminal region are also responsible for antigenic specificity.

3

Speaker(s)：

Sue-Min Huang

Topic

Field application of an inactivated grouper iridovirus vaccine

Abstract

Grouper iridovirus (GIV) is one of the major viral pathogens that destroys grouper aquaculture. The iridovirus isolates in Taiwan could be divided into 3 major genotypes, that were GIV, red sea bream iridovirus (RSIV) and infectious spleen and kidney necrosis iridovirus (ISKNV), respectively. The manufacturing license of an inactive vaccine against GIV was approved in November 2011. To promote immunization program, one million injection doses of vaccine were prepared and offered to fish farmers for free. The immunization program, launched in October 2011, applied 315,000 doses of vaccination in fish farms. The inactivated vaccines had been analyzed in two serial field trials for safety and efficacy in orang-spotted grouper (Epinephelus coioides) for two years. The vaccinated fish showed increased survival by 20-30% compared to that in non-vaccinated fish, and the weight gain in vaccinated groups was significantly higher than that in non-vaccinated groups. In addition, the vaccination program applied in giant grouper (Epinephelus lanceolatus) under clean field condition showed 100％ survival rates in both of vaccinated and non-vaccinated fish groups, but the weight gain in vaccinated groups was significantly higher than that in non-vaccine groups on 8 weeks post vaccination. The survival rates of downstream growing farms were more than 90%. The results showed that the tested vaccine protected against iridoviruses in grouper cultured in field conditions and it was safe for use in the target species.

Keyword：Iridovirus, vaccine, grouper