Pathobiological characterization and estimation of the basic reproduction number of a recombinant african swine fever virus in contact-exposed pigs in Vietnam

IF 2.7 2区农林科学 Q3 MICROBIOLOGY

Veterinary microbiology Pub Date : 2026-05-01 Epub Date: 2026-02-27 DOI:10.1016/j.vetmic.2026.110961

The Viet Hoang Nguyen , Ngoc Duong Vu , Viet Dung Nguyen , Thi Tam Than , Thuy Nga Dang , Huu Thien Nguyen , Thi Chau Giang Tran , Hoai Thuong Nguyen , Phuong Anh Nguyen , Ki-Hyun Cho , Seong-Keun Hong , Aruna Ambagala , Yeon-Hee Kim , Van Phan Le

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Abstract

African swine fever virus (ASFV) causes a highly lethal disease in domestic pigs, resulting in severe economic losses. This study examined the clinical course, viral dynamics, immune response, and pathological changes in pigs infected with a recombinant ASFV strain of p72 genotypes I/II (rASFV I/II) via direct inoculation or natural contact. The directly infected pig developed persistent fever (> 40 °C), anorexia, lethargy, and respiratory distress soon after the onset of viremia, and died six days post-inoculation (dpi). Contact-exposed pigs showed similar clinical signs and died between 12 and 21 days post-exposure (dpe). Real-time PCR revealed rapid viral replication in blood and secretions, with peak viral loads detected at or just before death. No detectable antibody response was observed in either group, indicating acute disease progression and high virulence. Gross pathological examination revealed severe lesions in the spleen, lymph nodes, gastrointestinal tract, and lungs. Epidemiological analysis using the susceptible–infectious–removed (SIR) model estimated the generation time (mean ± SD) as 1.101 ± 0.507 days. The basic reproduction number (R₀) was 1.201 (95% CI: 0.628–2.302) using the exponential growth method and 1.248 (95% CI: 0.310–3.236) using the maximum likelihood method. These findings demonstrate the high virulence and transmission potential of the rASFV I/II strain, highlighting the need for early detection and rapid containment measures.

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越南接触猪中重组非洲猪瘟病毒的病理生物学特征和基本繁殖数的估计。

非洲猪瘟病毒（ASFV）在家猪中引起高度致命的疾病，造成严重的经济损失。本研究通过直接接种或自然接触的方式，研究了猪感染重组ASFV p72基因型I/II （rASFV I/II）的临床过程、病毒动力学、免疫反应和病理变化。直接感染猪在出现病毒血症后不久出现持续发热（40℃）、厌食、嗜睡和呼吸窘迫，于接种后6天死亡。接触暴露的猪表现出类似的临床症状，并在接触后12至21天死亡。实时PCR显示病毒在血液和分泌物中快速复制，在死亡时或死亡前检测到病毒载量峰值。两组均未观察到可检测到的抗体反应，表明疾病进展急性且毒性高。大体病理检查显示脾脏、淋巴结、胃肠道和肺部有严重病变。流行病学分析采用易感-感染-去除（SIR）模型估计产生时间（平均±SD）为1.101 ± 0.507天。使用指数增长方法的基本复制数（R 0）为1.201 (95% CI: 0.628-2.302)，使用最大似然方法的基本复制数为1.248 （95% CI: 0.310-3.236）。这些发现表明了rASFV I/II株的高毒力和传播潜力，强调了早期发现和快速遏制措施的必要性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Veterinary microbiology 农林科学-兽医学

CiteScore

5.90

自引率

6.10%

发文量

221

审稿时长

52 days

期刊介绍： Veterinary Microbiology is concerned with microbial (bacterial, fungal, viral) diseases of domesticated vertebrate animals (livestock, companion animals, fur-bearing animals, game, poultry, fish) that supply food, other useful products or companionship. In addition, Microbial diseases of wild animals living in captivity, or as members of the feral fauna will also be considered if the infections are of interest because of their interrelation with humans (zoonoses) and/or domestic animals. Studies of antimicrobial resistance are also included, provided that the results represent a substantial advance in knowledge. Authors are strongly encouraged to read - prior to submission - the Editorials (''Scope or cope'' and ''Scope or cope II'') published previously in the journal. The Editors reserve the right to suggest submission to another journal for those papers which they feel would be more appropriate for consideration by that journal. Original research papers of high quality and novelty on aspects of control, host response, molecular biology, pathogenesis, prevention, and treatment of microbial diseases of animals are published. Papers dealing primarily with immunology, epidemiology, molecular biology and antiviral or microbial agents will only be considered if they demonstrate a clear impact on a disease. Papers focusing solely on diagnostic techniques (such as another PCR protocol or ELISA) will not be published - focus should be on a microorganism and not on a particular technique. Papers only reporting microbial sequences, transcriptomics data, or proteomics data will not be considered unless the results represent a substantial advance in knowledge. Drug trial papers will be considered if they have general application or significance. Papers on the identification of microorganisms will also be considered, but detailed taxonomic studies do not fall within the scope of the journal. Case reports will not be published, unless they have general application or contain novel aspects. Papers of geographically limited interest, which repeat what had been established elsewhere will not be considered. The readership of the journal is global.