Franzoni Giulia, Dei Giudici Silvia, Loi Federica, Sanna Daria, Floris Matteo, Fiori Mariangela, Sanna Maria Luisa, Madrau Paola, Scarpa Fabio, Zinellu Susanna, Giammarioli Monica, Cappai Stefano, De Mia Gian Mario, Laddomada Alberto, Rolesu Sandro, Oggiano Annalisa
Department of Animal Health, Istituto Zooprofilattico Sperimentale della Sardegna, 07100 Sassari, Italy.
Epidemiological Veterinary Regional Observatory, Istituto Zooprofilattico Sperimentale della Sardegna, 09125 Cagliari, Italy.
Vaccines (Basel). 2020 Sep 21;8(3):549. doi: 10.3390/vaccines8030549.
African swine fever virus (ASFV), the cause of a devastating disease affecting domestic and wild pigs, has been present in Sardinia since 1978. In the framework of the regional ASF eradication plan, 4484 illegal pigs were culled between December 2017 and February 2020. The highest disease prevalence was observed in the municipality with the highest free-ranging pig density, and culling actions drastically reduced ASFV circulation among these animals. ASFV-antibody were detected in 36.7% of tested animals, which were apparently healthy, thus, the circulation of low-virulence ASFV isolates was hypothesized. ASFV genome was detected in 53 out of 2726 tested animals, and virus isolation was achieved in two distinct culling actions. Two ASFV haemadsorbing strains were isolated from antibody-positive apparently healthy pigs: 55234/18 and 103917/18. Typing analysis revealed that both isolates belong to p72 genotype I, subgroup X; phylogenetic analysis based on whole genome sequencing data showed that they were closely related to Sardinian ASFV strains collected since 2010, especially 22653/Ca/2014. Our data suggested the absence of immune-escaped ASFV variants circulating among free-ranging pigs, indicating that other elements contributed to virus circulation among these animals. Understanding factors behind disease persistence in endemic settings might contribute to developing effective countermeasures against this disease.
非洲猪瘟病毒（ASFV）是一种影响家猪和野猪的毁灭性疾病的病原体，自1978年以来一直存在于撒丁岛。在区域非洲猪瘟根除计划的框架内，2017年12月至2020年2月期间扑杀了4484头非法猪。在自由放养的猪密度最高的市镇观察到最高的疾病流行率，扑杀行动大大减少了ASFV在这些动物中的传播。在36.7%的经检测看似健康的动物中检测到了ASFV抗体，因此，推测存在低毒力ASFV分离株的传播。在2726头经检测的动物中，有53头检测到了ASFV基因组，并在两次不同的扑杀行动中实现了病毒分离。从抗体呈阳性的看似健康的猪中分离出了两种ASFV血细胞吸附菌株：55234/18和103917/18。分型分析表明，这两种分离株均属于p72基因型I，X亚组；基于全基因组测序数据的系统发育分析表明，它们与自2010年以来收集的撒丁岛ASFV菌株密切相关，尤其是22653/Ca/2014。我们的数据表明，在自由放养的猪中不存在免疫逃逸的ASFV变体，这表明其他因素促成了该病毒在这些动物中的传播。了解地方病流行环境中疾病持续存在的因素可能有助于制定针对这种疾病的有效对策。
