Bavarian Health and Food Safety Authority, Veterinärstrasse 2, 85764, Oberschleißheim, Germany.
Institute of Diagnostic Virology, Friedrich-Loeffler-Institute, Insel Riems, Germany.
BMC Vet Res. 2020 May 24;16(1):149. doi: 10.1186/s12917-020-02310-w.
Bavaria, a large federal state in Germany, has been declared free from infections with Bovine Alphaherpesvirus 1 (BoHV-1) in 2011. To maintain this status the cattle population is monitored for antibodies against BoHV-1 regularly. Several years ago, infrequent but recurrent problems in this sero-surveillance were statistically put into correlation with the presence of antibodies against Bovine Alphaherpesvirus 2 (BoHV-2). In Europe, BoHV-2 is primarily known as the agent causing bovine herpes mammillitis. However, very little information about BoHV-2 infections in Bavaria is available so far. Therefore, the aims of this study were to determine BoHV-2 seroprevalences and to detect virus genomes in potential clinical samples.
6801 blood sera of healthy cattle from all over Bavaria were tested for antibodies against BoHV-2, revealing an overall seroprevalence of 5.51%. Interestingly, seroprevalences markedly varied between the North and the South of Bavaria, namely from 0.42 to 11.17%. Concurrently, the previously reported relation between the epidemiologically inexplicable sero-reactivities in BoHV-1 ELISAs and the presence of BoHV-2 infections were statistically corroborated in this study. To detect BoHV-2 genomes a fast and sensitive real time PCR was established. Using a multiple PCR strategy, tissue samples from skin lesions at relevant localizations, corresponding lymph nodes, and trigeminal ganglia from 111 animals, as well as nasal swabs from 918 bovines with respiratory symptoms were tested. However, BoHV-2 genomes were not detected in any of these samples.
BoHV-2 antibodies were found in samples from bovines all over Bavaria, albeit with an explicit South-North-divide. BoHV-2 genomes, however, could not be detected in any of the analyzed samples, indicating that acute clinical cases as well as obvious virus reactivation are relatively rare. Consequently, the future spread of BoHV-2 infections throughout Bavaria, particularly, after eradicating BoHV-1, has to be further monitored.
德国巴伐利亚州是一个大型联邦州，已于 2011 年宣布无牛疱疹病毒 1 型（BoHV-1）感染。为了保持这种状态，巴伐利亚州的牛群定期接受针对 BoHV-1 的抗体检测。几年前，在这种血清监测中出现了一些不常见但反复出现的问题，这些问题被统计上与牛疱疹病毒 2 型（BoHV-2）的抗体存在相关。在欧洲，BoHV-2 主要是导致牛疱疹性乳腺炎的病原体。然而，到目前为止，关于巴伐利亚州 BoHV-2 感染的信息非常有限。因此，本研究的目的是确定 BoHV-2 的血清流行率，并在潜在的临床样本中检测病毒基因组。
检测了来自巴伐利亚州各地的 6801 份健康牛血清样本，以检测针对 BoHV-2 的抗体，总体血清阳性率为 5.51%。有趣的是，巴伐利亚州北部和南部的血清阳性率差异显著，分别为 0.42%至 11.17%。同时，本研究还统计证实了之前报道的 BoHV-1 ELISA 中流行病学上无法解释的血清反应与 BoHV-2 感染之间的关系。为了检测 BoHV-2 基因组，建立了一种快速灵敏的实时 PCR 方法。使用多重 PCR 策略，对 111 头动物的相关部位皮肤病变、相应淋巴结和三叉神经节的组织样本以及 918 头有呼吸道症状的牛的鼻拭子进行了检测。然而，在任何样本中都未检测到 BoHV-2 基因组。
在巴伐利亚州各地的牛血清样本中发现了 BoHV-2 抗体，但存在明显的南北差异。然而，在任何分析样本中都未检测到 BoHV-2 基因组，表明急性临床病例和明显的病毒再激活相对较少。因此，在根除 BoHV-1 后，巴伐利亚州 BoHV-2 感染的进一步传播，特别是在根除 BoHV-1 后，必须进一步监测。
