Unterweger Christine, Debeerst Stephanie, Klingler Eva, Auer Angelika, Redlberger-Fritz Monika, Stadler Julia, Pesch Stefan, Lillie-Jaschniski Kathrin, Ladinig Andrea
Universitätsklinik für Schweine, Department für Nutztiere und öffentliches Gesundheitswesen in der Veterinärmedizin, Veterinärmedizinische Universität Wien.
Vetpraxis Hegerberg, Kasten.
Tierarztl Prax Ausg G Grosstiere Nutztiere. 2021 Dec;49(6):425-431. doi: 10.1055/a-1580-6938. Epub 2021 Dec 3.
In a gilt producing farm in Lower Austria, respiratory diseases occurred over the previous years in self-reared gilts after being introduced into the sow herd. In addition, fertility disorders in terms of late abortions and re-breeders were observed in the fall of 2019. Nasal swabs of 3 gilts with respiratory signs and fever were tested positive for influenza A virus (IAV) subtype H1avN1 by PCR. However, examination of serum samples from these animals at 2 different time points did not detect antibodies using the standard hemagglutination inhibition (HI) test of the laboratory. Examination of additional age groups likewise failed to detect H1avN1 antibody titers. In consequence to the extension of the diagnostic panel of the HI test by 7 additional H1avN1 test antigens, a clear seroconversion of the PCR positive sows against 2 different H1avN1 isolates could be measured. In addition, high antibody titers against these 2 H1avN1 strains were also detectable in the majority of the remaining age groups tested. Following the administration of the trivalent influenza vaccine, which has been approved throughout Europe, a significant improvement of the clinical presentation in the herd was achieved. The present case report illustrates that direct and indirect pathogen detection should be used in combination for targeted influenza diagnostics. In addition, it was shown that the continuous adaptation of test antigens to the isolates circulating in the field would be extremely crucial for the significance of the HI test.
在下奥地利州的一个 gilt 生产农场，过去几年中，自繁的后备母猪引入母猪群后出现了呼吸道疾病。此外，在 2019 年秋季观察到了晚期流产和返情等繁殖障碍问题。对 3 头有呼吸道症状和发热的后备母猪的鼻拭子进行 PCR 检测，结果显示甲型流感病毒（IAV）H1avN1 亚型呈阳性。然而，在两个不同时间点对这些动物的血清样本进行检测时，使用实验室标准血凝抑制（HI）试验未检测到抗体。对其他年龄组的检测同样未能检测到 H1avN1 抗体滴度。由于 HI 试验的诊断面板增加了 7 种额外的 H1avN1 检测抗原，可检测到 PCR 阳性母猪针对 2 种不同 H1avN1 分离株的明显血清转化。此外，在大多数检测的其余年龄组中也可检测到针对这 2 种 H1avN1 毒株的高抗体滴度。在接种了全欧洲批准使用的三价流感疫苗后，猪群的临床表现有了显著改善。本病例报告表明，应结合直接和间接病原体检测进行针对性的流感诊断。此外，还表明检测抗原不断适应田间流行的分离株对于 HI 试验的意义至关重要。
