Matos Miguel, Bilic Ivana, Palmieri Nicola, Mitsch Peter, Sommer Franz, Tvarogová Jana, Liebhart Dieter, Hess Michael
Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria.
Tierarzt GmbH Dr. Mitsch, Vienna, Austria.
Transbound Emerg Dis. 2022 Sep;69(5):2913-2923. doi: 10.1111/tbed.14446. Epub 2022 Jan 17.
Cutaneous fowlpox is a disease of chickens and turkeys caused by the fowlpox virus (FWPV), characterized by the development of proliferative lesions and scabs on unfeathered areas. FWPVs regularly carry an integrated, active copy of the reticuloendotheliosis virus (REV), and it has been hypothesized that such FWPVs are more problematic in the field. Extensive outbreaks are usually observed in tropical and sub-tropical climates, where biting insects are more difficult to control. Here, we report an epidemic of 65 cutaneous fowlpox cases in Austria in layer chickens (91% of the cases) and broiler breeders and turkeys, all of them unvaccinated against the disease, from October 2018 to February 2020. The field data revealed appearance in flocks of different sizes ranging from less than 5000 birds up to more than 20,000 animals, with the majority raised indoors in a barn system. The clinical presentation was characterized by typical epithelial lesions on the head of the affected birds, with an average decrease of 6% in egg production and an average weekly mortality of 1.2% being observed in the flocks. A real-time multiplex polymerase chain reaction (PCR) confirmed the presence of FWPV-REV DNA, not only in the lesions but also in the environmental dust from the poultry houses. The integration of the REV provirus into the FWPV genome was confirmed by PCR, and revealed different FWPV genome populations carrying either the REV long terminal repeats (LTRs) or the full-length REV genome, reiterating the instability of the inserted REV. Two selected samples were fully sequenced by next generation sequencing (NGS), and the whole genome phylogenetic analysis revealed a regional clustering of the FWPV genomes. The extensive nature of these outbreaks in host populations naïve for the virus is a remarkable feature of the present report, highlighting new challenges associated with FWPV infections that need to be considered.
皮肤型禽痘是由禽痘病毒（FWPV）引起的鸡和火鸡的一种疾病，其特征是在无毛部位出现增生性病变和结痂。FWPV通常携带整合的、活跃的网状内皮组织增殖症病毒（REV）拷贝，据推测，这种FWPV在实际应用中问题更大。在热带和亚热带气候地区通常会观察到广泛的疫情爆发，在这些地区，叮咬昆虫更难控制。在此，我们报告了2018年10月至2020年2月在奥地利发生的一起65例皮肤型禽痘疫情，病例涉及蛋鸡（占病例的91%）、肉种鸡和火鸡，所有这些禽类均未接种过该疾病的疫苗。现场数据显示，疫情出现在大小不等的鸡群中，从不到5000只鸡到超过20000只动物，其中大多数在室内的禽舍系统中饲养。临床表现的特征是受感染禽类头部出现典型的上皮病变，在鸡群中观察到产蛋量平均下降6%，每周平均死亡率为1.2%。实时多重聚合酶链反应（PCR）证实不仅在病变部位，而且在家禽舍的环境灰尘中都存在FWPV-REV DNA。通过PCR证实了REV前病毒整合到FWPV基因组中，并揭示了携带REV长末端重复序列（LTRs）或全长REV基因组的不同FWPV基因组群体，再次证明了插入的REV的不稳定性。通过下一代测序（NGS）对两个选定样本进行了全序列测定，全基因组系统发育分析揭示了FWPV基因组的区域聚类。这些在对该病毒无免疫力的宿主群体中广泛爆发的疫情是本报告的一个显著特征，突出了与FWPV感染相关的新挑战，需要加以考虑。
