Okamatsu Masatoshi, Tanaka Tomohisa, Yamamoto Naoki, Sakoda Yoshihiro, Sasaki Takashi, Tsuda Yoshimi, Isoda Norikazu, Kokumai Norihide, Takada Ayato, Umemura Takashi, Kida Hiroshi
Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Japan.
Virus Genes. 2010 Dec;41(3):351-7. doi: 10.1007/s11262-010-0530-3. Epub 2010 Sep 17.
In April and May 2008, whooper swans (Cygnus cygnus) were found dead in Hokkaido in Japan. In this study, an adult whooper swan found dead beside Lake Saroma was pathologically examined and the identified H5N1 influenza virus isolates were genetically and antigenically analyzed. Pathological findings indicate that the swan died of severe congestive edema in the lungs. Phylogenetic analysis of the HA genes of the isolates revealed that they are the progeny viruses of isolates from poultry and wild birds in China, Russia, Korea, and Hong Kong. Antigenic analyses indicated that the viruses are distinguished from the H5N1 viruses isolated from wild birds and poultry before 2007. The chickens vaccinated with A/duck/Hokkaido/Vac-1/2004 (H5N1) survived for 14 days after challenge with A/whooper swan/Hokkaido/1/2008 (H5N1), although a small amount of the challenge virus was recovered from the tissues of the birds. These findings indicate that H5N1 highly pathogenic avian influenza viruses are circulating in wild birds in addition to domestic poultry in Asia and exhibit antigenic variation that may be due to vaccination.
2008年4月和5月，日本北海道发现大天鹅（Cygnus cygnus）死亡。在本研究中，对在佐吕间湖附近发现死亡的一只成年大天鹅进行了病理检查，并对鉴定出的H5N1流感病毒分离株进行了基因和抗原分析。病理检查结果表明，这只天鹅死于肺部严重充血性水肿。对分离株HA基因的系统发育分析表明，它们是来自中国、俄罗斯、韩国和香港的家禽及野生鸟类分离株的子代病毒。抗原分析表明，这些病毒与2007年之前从野生鸟类和家禽中分离出的H5N1病毒不同。用A/鸭/北海道/Vac-1/2004（H5N1）疫苗接种的鸡在受到A/大天鹅/北海道/1/2008（H5N1）攻击后存活了14天，尽管在这些鸡的组织中回收了少量的攻击病毒。这些发现表明，H5N1高致病性禽流感病毒除了在亚洲家禽中传播外，还在野生鸟类中传播，并呈现出可能由于疫苗接种导致的抗原变异。
