Walczak Marek, Szczotka-Bochniarz Anna, Żmudzki Jacek, Juszkiewicz Małgorzata, Szymankiewicz Krzesimir, Niemczuk Krzysztof, Pérez-Núñez Daniel, Liu Lihong, Revilla Yolanda
National Veterinary Research Institute, 57 Partyzantów Avenue, 24-100 Pulawy, Poland.
Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Microbes in Health and Welfare Department, c/Nicolás Cabrera 1, 28049 Madrid, Spain.
Viruses. 2022 Aug 11;14(8):1756. doi: 10.3390/v14081756.
African swine fever remains one of the most economically important and dangerous diseases of the family. Until now, neither a safe vaccine nor a treatment against ASF has been available, which is why prevention of the disease involves biosecurity measures and early recognition based on accurate diagnosis. Nowadays, different strategies for ASF detection are discussed to reduce both animal suffering and the costs of ASF surveillance. This article aims to indicate the risk, with regard to non-invasive sampling, for the detection of ASFV. In this study, we analyzed data from three independent animal trials, in the framework of the detection of positive samples in different matrices (blood, sera, oral and rectal swabs) collected from nineteen domestic pigs infected with similar doses but under different scenarios, including different ASFV strains or routes of infection. Genetic material of ASFV was found in all matrices, but detection occurred earlier in the blood samples than in the oral and the rectal swabs. Furthermore, analyses revealed that at relevant sampling timepoints, PCR-positive blood samples were detected more frequently and reached higher percentages (up to 100% during fever) than oral and rectal swabs. Moreover, mean Ct values in blood samples collected from animals infected with virulent strains were significantly lower than in oral and rectal swabs, ensuring a higher probability of ASFV detection. High Ct values and occasional shedding in all tested matrices, in the cases of animals infected by an attenuated ASFV-strain, showed that blood sampling may be necessary to confirm the presence of anti-ASFV antibodies in sera. This study showed that during veterinary surveillance, blood sampling (for both PCR and serological analyses) is essential for the accurate diagnosis of ASF and provides the highest probability of detection of the disease.
非洲猪瘟仍然是该家族中经济上最重要且最危险的疾病之一。到目前为止，既没有安全的疫苗也没有针对非洲猪瘟的治疗方法，这就是为什么疾病预防涉及生物安全措施以及基于准确诊断的早期识别。如今，人们正在讨论不同的非洲猪瘟检测策略，以减少动物痛苦和非洲猪瘟监测成本。本文旨在指出非侵入性采样在检测非洲猪瘟病毒方面的风险。在本研究中，我们分析了来自三项独立动物试验的数据，这些试验是在检测从19头感染了相似剂量但处于不同情况（包括不同非洲猪瘟病毒株或感染途径）的家猪身上采集的不同基质（血液、血清、口腔和直肠拭子）中的阳性样本的框架内进行的。在所有基质中都发现了非洲猪瘟病毒的遗传物质，但血液样本中的检测比口腔和直肠拭子更早出现。此外，分析表明，在相关采样时间点，PCR阳性血液样本的检测频率更高，且百分比高于口腔和直肠拭子（发热期间高达100%）。此外，感染强毒株动物的血液样本中的平均Ct值明显低于口腔和直肠拭子，这确保了检测到非洲猪瘟病毒的更高概率。在感染减毒非洲猪瘟病毒株的动物的情况下，所有测试基质中的Ct值都很高且偶尔有病毒脱落，这表明可能需要进行血液采样以确认血清中抗非洲猪瘟病毒抗体的存在。这项研究表明，在兽医监测期间，血液采样（用于PCR和血清学分析）对于准确诊断非洲猪瘟至关重要，并且提供了检测该疾病的最高概率。
