Li Chenyu, Gao Chunliu, Tao Longfei, Cui Jin, Zhang Hui, Zheng Hui, Wei Rong, Gu Shaopeng, Sha Zhou, Ni Bo
College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, China.
China Animal Health and Epidemiology Center, Qingdao, China.
Front Vet Sci. 2024 Jul 1;11:1391513. doi: 10.3389/fvets.2024.1391513. eCollection 2024.
Senecaviurs A (SVA) infection, an emerging infectious disease in pig populations, is characterized by vesicular lesions predominantly affecting the mouth, snout, and hooves of infected pigs, similar to the symptoms of Foot and Mouth Disease Virus (FMDV). This disease first spread into China in 2015, causing great panic in the pig breeding industry. To determine the prevalence of SVA in pig herds in China from 2018 to 2021, a total of 4,901 pig tissue samples were collected from 18 provinces, autonomous regions and municipalities (P.A.M.s) for epidemiological investigation, virus isolation and genetic analysis. In 2021, the individual positive rates (IPRs) from the perspective of spatial distribution in East China, South China, Central China, North China, Southwest China, Northwest China, and Northeast China were 0, 0, 1.69, 0.94, 11.70, 3.31 and 2.21%, respectively. The herd positive rates (HPRs) were 0, 0, 9.52, 9.09, 50.00, 7.69 and 23.08%. From the perspective of temporal distribution, the IPR showed an overall downwards trend from 2018 to 2021, with only a slight increase in 2020. Moreover, the HPR decreased from 36.63 to 10.07%. From the perspective of population distribution in 2021, the IPR (2.62%) and HPR (12.00%) in apparently healthy pig herds (slaughterhouses) were greater than those in non-healthy pig herds (2.10 and 5.13%, respectively), consistent with the results in 2019. To characterize the prevalent strains, 10 SVA strains isolated from positive samples in 2019 were clustered in Clades I and VII; SVA-FJ039-2019, SVA-HuN032-2019, SVA-GX011-2019, SVA-FJ036-2019, SVA-GXF011-2019 and SVA-GXF053-2019 were clustered in Clade I; and SVA-FJ018-2019, SVA-SD069-2019, SVA-SD072-2019, and SVA-SD074-2019 were clustered in Clade VII. In conclusion, until 2021, the prevalence of SVA in pig herds in China was still relatively high, the contaminated area was still large, and there were a number of hidden infections. In the future, the epidemic status of SVA in pig herds in China must be closely monitored and the prevention and control measures must be adjusted in a timely manner.
赛尼卡病毒A（SVA）感染是猪群中一种新出现的传染病，其特征是水泡性病变主要影响受感染猪的口腔、口鼻部和蹄部，类似于口蹄疫病毒（FMDV）的症状。该病于2015年首次传入中国，在养猪业引起了极大恐慌。为确定2018年至2021年中国猪群中SVA的流行情况，共从18个省、自治区和直辖市采集了4901份猪组织样本进行流行病学调查、病毒分离和基因分析。2021年，从华东、华南、华中、华北、西南、西北和东北的空间分布来看，个体阳性率（IPR）分别为0、0、1.69%、0.94%、11.70%、3.31%和2.21%。群体阳性率（HPR）分别为0、0、9.52%、9.09%、50.00%、7.69%和23.08%。从时间分布来看，2018年至2021年IPR总体呈下降趋势，仅在2020年略有上升。此外，HPR从36.63%降至10.07%。从2021年的群体分布来看，健康猪群（屠宰场）的IPR（2.62%）和HPR（12.00%）高于非健康猪群（分别为2.10%和5.13%），与2019年的结果一致。为了对流行毒株进行特征分析，2019年从阳性样本中分离出的10株SVA毒株聚类在进化枝I和VII中；SVA-FJ039-2019、SVA-HuN032-2019、SVA-GX011-2019、SVA-FJ036-2019、SVA-GXF011-2019和SVA-GXF053-2019聚类在进化枝I中；SVA-FJ018-2019、SVA-SD069-2019、SVA-SD072-2019和SVA-SD074-2019聚类在进化枝VII中。总之，截至2021年，中国猪群中SVA的流行率仍然较高，污染区域仍然较大，并且存在大量隐性感染。未来，必须密切监测中国猪群中SVA的流行状况，并及时调整防控措施。
