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Seminar 868  
Date:2016-12-21
Update:2017-11-02

  

Seminar:  868  

1

Speaker(s)

Yu-Ju Lin

Topic

Characterization of clade 2.3.4.4 H5 avian influenza viruses in Taiwan and a visit to the QIA avian influenza diagnosis laboratory in Korea

Abstract

Taiwan recently experienced massive outbreaks of avian influenza caused by the introduction of novel reassortants of H5N2, H5N3 and H5N8 avian influenza viruses starting in January 2015. By November 2016, 1,054 cases of the novel H5 HPAI were confirmed, and geese were the most affected species. Our phylogenetic analysis indicated that the H5 viruses belonged to the clade 2.3.4.4 of H5 influenza virus and five genotypes of the H5 viruses were identified during this epidemic: H5N2, H5N3 and three belonging to H5N8. Most of the infected farms were attacked by the novel H5N2 viruses. The novel H5N3 viruses have not been detected since March, 2015. To investigate the pathogenicity of the novel H5N2 virus in different poultry breeds, the poultry were inoculated with an H5N2 strain (A/Goose/Taiwan/a4/2015) intranasally. The experimental infection resulted in mortality rates of 75% and 50% in chickens and Muscovy ducks, respectively. The survival rates in Tsaiya duck, Peking duck and Mule duck were 100%. All poultry that survived the experimental infection were seroconverted with the exception of one chicken individuum.. The H5Nx strains found in Taiwan, along with H5N8 from several European countries and H5N6 found in Korea and Japan, respectively, are all phylogenetically clustered into clade 2.3.4.4 but also grouped into sub-clades owing to their source of origin. This suggests that the H5 viruses within the clade 2.3.4.4 have a fast evolutionary and transmission rate. The development of antibodies may add further evolutionary pressure to these H5 viruses. Thus, it is necessary to strengthen disinfection policies in poultry farms to prevent new virus invasion. Further, serological surveillance in ducks should be more vigorous so as to monitor the possible reassortment of influenza viruses.

This group was invited by the Avian Disease Department in the Animal and Plant Quarantine Agency of Korea, and two of our staff members from the Division of Epidemiology visited the agency in November, 2016. The purpose of the technical visit was to share experiences in the biocontainment facilities of avian influenza, avian influenza diagnostics, and in the planning and execution of domestic and wild bird monitoring programs.

2

Speaker(s)

Chen-Shen Huang

Topic

A report on the 59th Annual Meeting of the American Association of Veterinary Laboratory Diagnosticians

Abstract

In order to highlight our research on animal bacterial disease diagnostics, increase the international visibility of our institute, as well as to exchange with foreign scholars, and thereby absorb new knowledge in bacterial disease diagnosis, I participated in a poster presentation at the 59th Annual Meeting of the American Association of Veterinary Laboratory Diagnosticians, (AAVLD). AAVLD was established to promote the scientific advancement of veterinary diagnostic laboratories, global animal health and One Health Initiative. This year’s session was held from October 13 to 19, 2016 at Sheraton Hotel in Greensboro, North Carolina. My presentation topic was entitled: “Genotyping of Mycobacterium bovis in ruminants in Taiwan from 2014-2016”.

3

Speaker(s)

Yen-Ping Chen

Topic

Effect of salinity on avian influenza virus and Newcastle disease virus infectivity in salted duck eggs

Abstract

The present study was performed to determine the effects of salinity on the infective potential of the highly pathogenic avian influenza (HPAI) H5N8 virus and Newcastle disease (ND) virus (Ishii strain) in salted duck eggs. The raw duck eggs were inoculated with 27 HA titers of HPAI virus and ND virus, respectively. The eggs were then sealed with hot glue and soaked in saturated brine at room temperature for 10 and 15 days, respectively. Both of the viruses were also directly mixed with equal volumes of the saturated brine. The salted egg homogenate and the virus-brine mixture were inoculated into embryonated chicken eggs to evaluate the infectivity of the viruses. The H5N8 virus in salted duck eggs lost infectivity after soaked for 10 and 15 days. However, the ND virus in salted duck eggs remained viable after soaked for 10 and 15 days. In addition, both of the viruses lost infectivity after being directly added to the saturated brine for 10 and 15 days. The results of this study can thus be a useful reference for the safety of salted duck eggs originating from farms contaminated with AI and ND viruses.

4

Speaker(s)

Kuo-Jung Tsai

Topic

Training on African swine fever diagnostic techniques in Spain

Abstract

In order to implement a program for the diagnosis and surveillance of African swine fever (ASF) at the Animal Health Research Institute (AHRI), we sent an assistant researcher to a training course on ASF diagnostic techniques at the Centro de Investigación en Sanidad Animal (CISA), in Spain, September 10- 18 2016. CISA is listed by the Food and Agriculture Organization of the United Nation as a European Centre of Reference for ASF. The trainee from AHRI learned routine diagnosis of ASF, including via enzyme-linked immunosorbent assays (ELISA), indirect immunoperoxidase techniques, and real-time polymerase chain reactions in a biosafety level 3 laboratory at the training course. Through the training course, the trainee received additional information about ASF diagnosis and increased familiarity with the trainers at CISA. This will provide a useful basis for future consulatations with CISA staff concerning ASF diagnosis, the obtainment of ASF positive controls, and the set up of new ASF diagnostic techniques at AHRI.