Department of Animal Medicine, Production and Health (MAPS), University of Padua, Legnaro, Italy.
Transbound Emerg Dis. 2019 Jul;66(4):1548-1557. doi: 10.1111/tbed.13180. Epub 2019 Apr 10.
Porcine circovirus 3 (PCV-3) has emerged as a potential threat for swine industry, being consistently reported in the presence of several clinical signs all around the world. Recently, its presence in wild boar has been demonstrated at high prevalence. This evidence is surprising since the lower density of wild populations might not be expected to sustain such efficient viral transmission. Porcine circoviruses were proven to exhibit a certain plasticity in the host tropism and were detected in unrelated species, like mice, dogs and ruminants. However, if this scenario applies also to wild animals remains to be established. Therefore, this study aimed to investigate the presence of PCV-3 in wild ungulates other than wild boar and in related hematophagous ectoparasites. One hundred and nine animals were sampled from different hilly and mountain areas of Friuli Venezia Giulia, including 9 chamois (Rupicapra rupicapra), 17 red deer (Cervus elaphus), 4 mouflons (Ovis musimon), 50 roe deer (Capreolus capreolus) and 29 wild boars (Sus scrofa). Additionally, host-matched ectoparasites were collected when present. Porcine circovirus 3 was diagnosed using molecular techniques and sequencing. This study results confirmed the high PCV-3 occurrence in wild boar and reported for the first time its presence, at low prevalence, in chamois and roe deer. Moreover, two ticks (Ixodes ricinus), one of which non-engorged, collected from PCV-3 negative roe deer, tested PCV-3 positive. The genetic characterization of some of the strains collected from non-swine hosts allowed to prove that, albeit clearly part of PCV-3 species, they were genetically unique, demonstrating the absence of among-samples contamination and thus confirming the actual presence of PCV-3 genome in these new hosts. Therefore, this study highlights an unexpected broad PCV-3 distribution and circulation in the wild, rising further questions on porcine circoviruses infectious cycle, epidemiology and origin, which will deserve additional investigations.
猪圆环病毒 3 型（PCV-3）已成为养猪业的潜在威胁，在世界各地的多种临床症状中均有报道。最近，在野猪中也发现了高流行率的 PCV-3。这一证据令人惊讶，因为野猪种群密度较低，预计不会出现如此高效的病毒传播。猪圆环病毒在宿主嗜性上表现出一定的可塑性，并在老鼠、狗和反刍动物等无关物种中被检测到。然而，这种情况是否也适用于野生动物还有待确定。因此，本研究旨在调查除野猪以外的野生有蹄类动物和相关吸血外寄生虫中 PCV-3 的存在情况。从弗留利-威尼斯朱利亚的不同丘陵和山区采集了 109 个样本，包括 9 只岩羚羊（Rupicapra rupicapra）、17 只马鹿（Cervus elaphus）、4 只摩弗伦羊（Ovis musimon）、50 只狍（Capreolus capreolus）和 29 只野猪（Sus scrofa）。此外，当有宿主匹配的外寄生虫时，也会采集它们。使用分子技术和测序来诊断猪圆环病毒 3 型。本研究结果证实了野猪中 PCV-3 的高发生率，并首次报道了其在岩羚羊和狍鹿中的低流行率存在。此外，从 PCV-3 阴性狍鹿身上采集到的两只蜱（Ixodes ricinus），其中一只是未吸血的，检测到 PCV-3 呈阳性。从非猪宿主采集的一些毒株的遗传特征证明，尽管它们明显属于 PCV-3 种，但它们在遗传上是独特的，这表明不存在样本间的污染，从而证实了这些新宿主中实际存在 PCV-3 基因组。因此，本研究强调了 PCV-3 在野外的广泛分布和传播，进一步引发了关于猪圆环病毒感染周期、流行病学和起源的问题，这些问题值得进一步研究。
