Jeong Ok-Mi, Kim Min-Chul, Kim Min-Jeong, Kang Hyun-Mi, Kim Hye-Ryoung, Kim Yong-Joo, Joh Seong-Joon, Kwon Jun-Hun, Lee Youn-Jeong
National Veterinary Research and Quarantine Service, Anyang 430-824, Korea.
J Vet Sci. 2009 Mar;10(1):53-60. doi: 10.4142/jvs.2009.10.1.53.
Highly pathogenic avian influenza viruses (HPAIV) of the H5N1 subtype have spread since 2003 in poultry and wild birds in Asia, Europe and Africa. In Korea, the highly pathogenic H5N1 avian influenza outbreaks took place in 2003/2004, 2006/2007 and 2008. As the 2006/2007 isolates differ phylogenetically from the 2003/2004 isolates, we assessed the clinical responses of chickens, ducks and quails to intranasal inoculation of the 2006/2007 index case virus, A/chicken/Korea/IS/06. All the chickens and quails died on 3 days and 3-6 days post-inoculation (DPI), respectively, whilst the ducks only showed signs of mild depression. The uninoculated chickens and quails placed soon after with the inoculated flock died on 5.3 and 7.5 DPI, respectively. Both oropharyngeal and cloacal swabs were taken for all three species during various time intervals after inoculation. It was found that oropharyngeal swabs showed higher viral titers than in cloacal swabs applicable to all three avian species. The chickens and quails shed the virus until they died (up to 3 to 6 days after inoculation, respectively) whilst the ducks shed the virus on 2-4 DPI. The postmortem tissues collected from the chickens and quails on day 3 and days 4-5 and from clinically normal ducks that were euthanized on day 4 contained the virus. However, the ducks had significantly lower viral titers than the chickens or quails. Thus, the three avian species varied significantly in their clinical signs, mortality, tissue virus titers, and duration of virus shedding. Our observations suggest that duck and quail farms should be monitored particularly closely for the presence of HPAIV so that further virus transmission to other avian or mammalian hosts can be prevented.
H5N1亚型高致病性禽流感病毒（HPAIV）自2003年以来在亚洲、欧洲和非洲的家禽和野鸟中传播。在韩国，2003/2004年、2006/2007年和2008年发生了高致病性H5N1禽流感疫情。由于2006/2007年分离株在系统发育上与2003/2004年分离株不同，我们评估了鸡、鸭和鹌鹑经鼻接种2006/2007年首例病例病毒A/鸡/韩国/IS/06后的临床反应。所有鸡和鹌鹑分别在接种后3天和3 - 6天死亡，而鸭仅表现出轻度抑郁症状。接种后不久与接种鸡群放在一起的未接种鸡和鹌鹑分别在接种后5.3天和7.5天死亡。在接种后的不同时间间隔对所有三个物种采集口咽和泄殖腔拭子。结果发现，口咽拭子的病毒滴度高于适用于所有三种禽类的泄殖腔拭子。鸡和鹌鹑在死亡前（分别在接种后3至6天）一直排毒，而鸭在接种后2 - 4天排毒。在第3天、第4 - 5天从鸡和鹌鹑以及在第4天安乐死的临床正常鸭身上采集的死后组织中含有病毒。然而，鸭的病毒滴度明显低于鸡或鹌鹑。因此，这三种禽类在临床症状、死亡率、组织病毒滴度和排毒持续时间方面有显著差异。我们的观察结果表明，应特别密切监测鸭场和鹌鹑场是否存在高致病性禽流感病毒，以防止病毒进一步传播给其他禽类或哺乳动物宿主。
