Fabri N D, Santman-Berends I M G A, Roos C A J, van Schaik G, Het Lam J, Germeraad E A, Mars M H
Royal GD, 7418 EZ Deventer, the Netherlands.
Faculty of Veterinary Medicine, Department of Population Health Sciences, Utrecht University, 3584 CM Utrecht, the Netherlands.
JDS Commun. 2025 Mar 12;6(3):394-399. doi: 10.3168/jdsc.2024-0703. eCollection 2025 May.
In March 2024, an infection with highly pathogenic avian influenza (HPAI) virus subtype H5N1 of the HA clade 2.3.4.4b was detected in dairy cows in Texas. Following this first detection, the virus was identified in multiple states in the United States, with spillover into other mammals. This raised concerns in the Netherlands that despite having an effective monitoring and surveillance system, H5N1 virus infections in Dutch cattle could have occurred. The aim of this study was therefore to retrospectively screen Dutch cattle for HPAI virus infections for the period between 2022 and 2024. A total of 2,190 archived cattle serum samples from 367 different herds were selected, with an average of 6 samples per herd. These samples were tested using an influenza A blocking ELISA. A Luminex H5/H7 assay was used to confirm and subtype ELISA-positive samples. The influenza A blocking ELISA detects antibodies against all influenza A virus subtypes, whereas the Luminex assay can differentiate antibodies against the surface proteins haemagglutinin (HA or H) 5 and 7 (H5/H7), and neuraminidases (NA or N) 1 to 9 (N1-N9). Four samples (0.2%) reacted positive in the influenza A blocking ELISA, all from different herds located in different parts of the Netherlands. However, all 4 samples tested negative in the Luminex H5/H7 assay, indicating that the samples did not have antibodies against H5, H7, and N1 to N9. The 99.8% specificity of the ELISA may explain the ELISA-positive results. The ELISA used in this study is a multispecies test that has not yet been validated for use in cattle. The duration of detectable antibodies in cattle is unknown, as is the sensitivity to detect past infections with influenza A virus subtypes in cattle for the Dutch situation. Therefore results should be interpreted with caution. The lack of detected antibody responses in cattle in the Netherlands from 2022 to 2024 aligns with the absence of any indication for clinical cases in Dutch cattle over recent years in the national monitoring and surveillance system.
2024年3月，在得克萨斯州的奶牛中检测到感染了高致病性禽流感（HPAI）病毒H5N1亚型，属于2.3.4.4b血凝素（HA）进化枝。首次检测到该病毒后，在美国多个州都发现了这种病毒，并传播到了其他哺乳动物。这引发了荷兰的担忧，即尽管拥有有效的监测和监督系统，但荷兰的牛群仍可能感染H5N1病毒。因此，本研究的目的是回顾性筛查2022年至2024年期间荷兰牛群中的高致病性禽流感病毒感染情况。总共从367个不同牛群中选取了2190份存档的牛血清样本，每个牛群平均有6份样本。这些样本使用甲型流感阻断酶联免疫吸附测定（ELISA）进行检测。使用Luminex H5/H7检测法对ELISA阳性样本进行确认和亚型鉴定。甲型流感阻断ELISA可检测针对所有甲型流感病毒亚型的抗体，而Luminex检测法可区分针对表面蛋白血凝素（HA或H）5和7（H5/H7）以及神经氨酸酶（NA或N）1至9（N1 - N9）的抗体。有4份样本（0.2%）在甲型流感阻断ELISA中呈阳性反应，均来自荷兰不同地区的不同牛群。然而，所有4份样本在Luminex H5/H7检测法中均呈阴性，这表明这些样本没有针对H5、H7以及N1至N9的抗体。ELISA的99.8%的特异性可能解释了ELISA阳性结果。本研究中使用的ELISA是一种多物种检测方法，尚未在牛群中得到验证。牛体内可检测到抗体的持续时间未知，对于荷兰的情况，检测牛群过去感染甲型流感病毒亚型的敏感性也未知。因此，对结果的解释应谨慎。2022年至2024年期间在荷兰牛群中未检测到抗体反应，这与国家监测系统中近年来荷兰牛群无任何临床病例迹象相符。
