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Abstract
During the recent epidemic of novel H5 highly pathogenic avian influenza (HPAI) in Taiwan, high mortality was observed among geese, chickens, turkeys, and muscovy ducks. We characterized lesions and viral antigen distribution using histopathology and immunohistochemistry (IHC) in geese, chickens, turkeys, and muscovy ducks naturally infected with the novel H5 HPAI virus. Grossly, the most common lesions in the four species were multifocal hemorrhagic necrosis in the pancreas and heart. Histologic lesions were characterized by hemorrhage, necrosis, inflammation, or a combination of these features in the brain, heart, pancreas, and kidney. Notably, splenic and hepatic necrosis were commonly observed in waterfowl. In IHC the viral nucleoprotein antigens were closely associated with histopathologic lesions. In waterfowl viral antigen was most often detected in the liver and spleen, but viral antigen detected in the intestinal lamina propria in muscovy ducks was higher than that in geese. Immunohistochemical demonstration of HPAIV nucleoprotein in brain, heart, and kidney was stronger in poultry than in waterfowl. Our study suggested that the best visceral samples for the detection of the novel H5 HPAI virus in waterfowl were heart, liver, and spleen, and the best samples for the detection in gallinacean were brain, heart, and kidney.
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Abstract
Beginning in January 2014, a distinct group of highly pathogenic avian influenza (HPAI) H5 reassortant viruses (H5N8, clade 2.3.4.4) caused outbreaks in South Korea. By late 2014 it had spread to Japan, the Russian Federation, Europe, and North America. In January 2015 H5Nx clade 2.3.4.4 AIVs were detected in Taiwan and caused outbreaks in poultry. To better understand genetic relatedness between these viruses in different regions, we sequenced all gene segments of 24 Taiwan H5Nx viruses and compared them with AIV sequences in GenBank. There were four novel HPAI H5Nx reassortant pattern viruses (1 H5N2, 1 H5N3, and 2 H5N8) emerging into Taiwan. All the four novel H5Nx reasortants evolved from early members of H5N1 clade 2.3.4.4 and contain at least two wild-bird-origin AIV RNA segments. This rapid emergence of new H5Nx combinations is unprecedented in the[1] H5N1 evolutionary history. Further work to monitor for such reassortments and an evaluation of these viruses are warranted.
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Abstract
The main purpose of the trip to France was to visit Dr. Florence Liquet at Nancy Laboratory for Rabies and Wildlife and Dr. Hervé Bourhy at the Pasteur Institute. Both institutes belong to WHO Collaborating Centres for Rabies Research. In this presentation, the visit overview and the content of the discussions are introduced. The information obtained from the Rabies in The Americas (RITA) conference I attended with Dr. Liguet is also presented. The annual conference is held each year in the U.S., Canada, and Mexico by turns addressing various research projects related to rabies in the fields of public health, prevention medicine, and epidemiology. This year, thanks to the invitation from Dr. Liquet, I attended RITA in the US to present a research paper entitled “Replication Properties of Taiwan Ferret Badger Rabies Virus in Mice,” as her co-author.
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