Spackman Erica, Pantin-Jackwood Mary J, Swayne David E, Suarez David L
Southeast Poultry Research Laboratory, USDA, Agricultural Research Service, 934 College Station Road, Athens, GA 30605, USA.
Avian Dis. 2009 Jun;53(2):276-80. doi: 10.1637/8520-111708-Reg.1.
Monitoring of poultry, including domestic ducks, for avian influenza (AI) virus has increased considerably in recent years. However, the current methods validated for the diagnosis and detection of AI virus infection in chickens and turkeys have not been evaluated for performance with samples collected from domestic ducks. In order to ensure that methods for the detection of AI virus or AI virus antibody will perform acceptably well with these specimens, samples collected from domestic ducks experimentally infected with a U.S. origin low pathogenicity AI virus, A/Avian/NY/31588-3/00 (H5N2), were evaluated. Oropharyngeal (OP) and cloacal swabs were collected at 1, 2, 3, 4, 5, 7, 10, 14, and 21 days postinoculation (PI) for virus detection by virus isolation, which was considered the reference method, and real-time RT-PCR. In addition, two commercial antigen immunoassays were used to test swab material collected 2-7 days PI. Virus isolation and real-time RT-PCR performed similarly; however, the antigen immunoassays only detected virus during the peak of shed, 2-4 days PI, and both kits detected virus in fewer than half of the samples that were positive by virus isolation. Cloacal swabs yielded more positives than OP swabs with all virus detection tests. To evaluate AI virus antibody detection serum was collected from the ducks at 7, 14, and 21 days PI and was tested by agar gel immunodiffusion (AGID) assay, a commercial blocking enzyme-linked immunosorbent assay (ELISA), and homologous hemagglutination inhibition (HI) assay, which was used as the reference method. Results for the ELISA and HI assay were almost identical with serum collected at 7 and 14 days PI; however, by 21 days PI 100% of the samples were positive by HI assay and only 65% were positive by ELISA. At all time points AGID detected antibody in substantially fewer samples than either ELISA or HI assay.
近年来，对包括家鸭在内的家禽进行禽流感（AI）病毒监测的力度大幅增加。然而，目前已验证用于诊断和检测鸡和火鸡中AI病毒感染的方法，尚未针对从家鸭采集的样本进行性能评估。为确保检测AI病毒或AI病毒抗体的方法对这些样本的检测效果良好，对从实验感染美国低致病性AI病毒A/禽/纽约/31588 - 3/00（H5N2）的家鸭采集的样本进行了评估。在接种后1、2、3、4、5、7、10、14和21天采集口咽（OP）和泄殖腔拭子，通过病毒分离（被视为参考方法）和实时RT - PCR检测病毒。此外，使用两种商业抗原免疫测定法检测接种后2 - 7天采集的拭子样本。病毒分离和实时RT - PCR表现相似；然而，抗原免疫测定法仅在排毒高峰期（接种后2 - 4天）检测到病毒，且两种试剂盒检测到的病毒样本数量不到病毒分离阳性样本的一半。在所有病毒检测试验中，泄殖腔拭子产生的阳性样本比OP拭子更多。为评估AI病毒抗体检测，在接种后7、14和21天从鸭采集血清，并通过琼脂凝胶免疫扩散（AGID）试验、一种商业阻断酶联免疫吸附测定（ELISA）和同源血凝抑制（HI）试验（用作参考方法）进行检测。ELISA和HI试验在接种后7天和14天采集的血清中的结果几乎相同；然而，到接种后21天，HI试验中100%的样本呈阳性，而ELISA仅65%的样本呈阳性。在所有时间点，AGID检测到抗体的样本数量远少于ELISA或HI试验。
