Search Results (702)

African swine fever (ASF) is a highly contagious and often fatal viral disease of pigs that poses serious economic consequences to the swine industry due to its high mortality rate and rapid spread. Currently, the identification of infectious ASF virus (ASFV) is the confirmatory test when clinical samples are positive for ASFV by any other diagnostic methods. Detection of infectious ASFV requires the availability of primary swine macrophage cultures as a cell substrate. We demonstrate here that cryopreserved swine primary macrophages are a suitable cell substrate for the detection, isolation and propagation of ASFV, showing similar results as when fresh swine macrophages are utilized. The possibility of using cryopreserved macrophages for detecting infectious ASFV would improve the efficacy of diagnostics in ensuring the availability of macrophage cell cultures during an emergency response. Full article

African swine fever (ASF), caused by African swine fever virus (ASFV), is a highly destructive transboundary disease in domestic pigs. The circulating virus in this study belonged to ASFV genotype II, commonly associated with high virulence. In endemic regions such as Thailand, limited vaccine availability and shortages of naïve breeding stock necessitate reliance on early detection, surveillance, and the retention of convalescent sows, thereby raising concerns regarding viral persistence and reproductive performance. This study evaluated the long-term reproductive performance of convalescent sows compared with naïve cohorts under co-habitation conditions, while assessing the efficacy of passive surveillance and strict biosecurity in preventing viral transmission from both internal and external sources. Convalescent sows showed reproductive performance comparable to naïve cohorts across two parities. Long-term co-habitation with naïve sentinel pigs was not associated with detectable viral transmission, although low-level viral persistence or intermittent shedding cannot be excluded. From a disease control perspective, the transition from delayed detection to enhanced passive surveillance facilitated early clinical recognition and targeted removal (“tooth extraction”) of infected animals, effectively limiting intra-herd transmission without full depopulation. Importantly, irrespective of the uncertain carrier status, strict biosecurity and rapid response protocols appeared effective in mitigating both external introduction and within-farm transmission of ASFV. These findings suggest that, under appropriate management and biosecurity conditions, convalescent sows may be reintegrated into production systems with caution. Full article

African swine fever (ASF) remains a major challenge for global animal disease prevention and control. Public sentiment during ASF, along with farmer and consumer behavior, are underexplored factors in ASF control. This study examines how public sentiment influences farmers’ risk perceptions and consumers’ behavioral responses, including consumption substitution intention and pork price expectations, and assesses the implications of these behaviors for disease control effectiveness. Using provincial panel data from China (June 2021–November 2022), sentiment analysis of 1.19 million Weibo posts, and a micro-level survey of 920 farmers, we combine panel regression, spatial econometric analysis, and micro-level behavioral evidence. Results show that public sentiment significantly elevates farmers’ risk perception, which may influence reporting decisions, marketing timing, and biosecurity investment, thereby increasing the complexity of surveillance and disease control. Sentiment intensifies substitution intentions and shapes pork price expectations, leading to reduced demand for formally marketed pork and potential shifts to lower-traceability or less-inspected channels. Spatial analysis indicates that the half-decay distance for amplifying ASF risk via sentiment is about 1300 km, providing parameters for cross-jurisdictional coordination. These findings support integrating socio-behavioral indicators into veterinary early warning systems and designing targeted disease risk communication under a broader One Health framework. Full article

Porcine circovirus type 2 (PCV2) is a pathogen of major importance in swine that is characterized by ongoing genetic evolution. To provide an updated epidemiological assessment for China, our study analyzed 1051 clinical samples collected from 27 provincial-level regions between 2023 and 2024. The overall PCV2 positivity rate was 65.18%, with detection rates showing significant seasonal variation, with higher rates in spring and summer. Genotypic analysis of 379 open reading frame 2 (ORF2) sequences identified PCV2d as the dominant genotype (78.89%), and no significant geographic clustering was observed. Coinfection with porcine reproductive and respiratory syndrome virus (PRRSV) is common, yet statistical tests have revealed an epidemiologically independent relationship between the two viruses. Notably, analysis of the capsid (Cap) protein revealed that high-frequency amino acid mutations were concentrated in immunodominant loop regions. These mutations resulted in genotype-specific substitutions within key neutralizing epitopes. This study provides the latest large-scale national baseline data on PCV2 in China for 2023–2024. It systematically analyzes the epidemiological characteristics of the dominant PCV2d genotype in the post-African Swine Fever era, the patterns of antigenic epitope mutations in the Cap protein, and their potential impact on vaccine efficacy. The study fills a gap in recent national epidemiological data on PCV2 in China and provides a basis for the targeted prevention and control of PCV2 and the updating of vaccine strains. Full article

The capsid protein pE120R of African swine fever virus (ASFV) is highly immunogenic and is thought to play an important role in viral replication, yet its molecular characteristics and functions during infection remain poorly understood. Here, we generated two monoclonal antibodies (mAbs), 1C11 and 3G7, against ASFV pE120R and characterized their specificity and utility. Epitope mapping showed that 1C11 recognized the linear epitope ¹⁰⁹KKHLFP¹¹⁴, whereas 3G7 recognized ¹¹²LFPKL¹¹⁶. These antibodies enabled analysis of pE120R expression and localization during ASFV infection, demonstrating that pE120R is expressed at a late stage and partially co-localizes with the structural protein p54 in viral factories. Together, these results provide valuable immunological tools for further investigation of pE120R in ASFV replication and pathogenesis. Full article

African swine fever (ASF) has become one of the most significant transboundary animal diseases affecting countries worldwide. Wild boars play a major role in virus persistence and in local spread through geographical contiguity, while long-distance and transboundary dissemination is more commonly associated with human-mediated activities, particularly the movement of contaminated pork products and materials. Hunting is frequently considered a central tool for disease control; however, its epidemiological impact remains debated. This review comparatively analyses the approaches adopted by countries of European continent affected by ASF, paying particular attention to the role of hunting within integrated management strategies. The review examines country-specific control measures, including surveillance systems, carcass search and removal, fencing, zoning, and population reduction policies. The analysis shows that successful eradication was associated with early detection, temporary suspension of hunting in infected core areas, rapid spatial containment through fencing, and intensive passive surveillance based on systematic carcass removal. Hunting was reintroduced only after containment, as a regulated depopulation tool under strict biosecurity supervision. In contrast, where the virus was already widespread at detection and containment measures were delayed or fragmented, intensified hunting alone did not prevent endemic persistence. These findings indicate that hunting is neither inherently protective nor detrimental; rather, its effectiveness depends on timing, coordination, and integration within a structured epidemiological framework. Effective control requires combining wildlife management with surveillance, biosecurity, and clear governance. Full article

The continuous and rapid spread of African swine fever (ASF) still poses a significant threat to Eurasian wild boar and domestic pigs, leading to substantial economic losses in all associated sectors annually. In Europe, including Germany, affected wild boar populations have become an important driver and host of ASF virus (ASFV), and monitoring and surveillance is key to tailor control measures that impede viral spread. While molecular methods are used to confirm the disease and to monitor viral evolution, serology gains importance in endemically affected regions as it provides insights into disease dynamics and possible attenuation of ASFV strains. Frontline serological diagnosis is done using ELISA assays, of which several are commercialized. However, accurate performance of ELISA assays is key for correct interpretation of wild boar samples. Due to the various stages of hemolysis and decay, field samples from wild boar can be challenging for ELISA assays. To assess which indirect or competitive ELISA kit performs best when dealing with such samples, we compared the sensitivity and specificity of four commercially available ELISA kits that are licensed in Germany, as well as three unlicensed but commercially available kits. For this comparison, we used all wild boar samples submitted to the National Reference Laboratory (NRL) for ASF in years 2021 and 2022, as well as samples from domestic pigs to have a control cohort where sample quality is optimal. We observed that wild boar samples, varying in stage of hemolysis and decay, were challenging for all kits included in this study. However, samples of domestic pigs were largely interpreted correctly by ELISA, using immunoperoxidase test as verification method. Additionally, the comparability of results obtained by regional laboratories was high. Our study provides data that highlights the importance of careful kit selection, assessment of sample quality, and data interpretation for effective ASFV surveillance and control. Full article

Background: African swine fever virus (ASFV) causes a fatal hemorrhagic disease in domestic pigs and wild boars. While live attenuated vaccines (LAVs) provide protection, their use raises safety concerns. Therefore, the aim of the present study was to identify viral B-cell antigens associated with protection and to test their potential using highly immunogenic vaccine delivery platforms. Methods: We employed a microarray of 169 ASFV proteins expressed in a cell-free prokaryotic system to identify immunodominant antigens using sera from immune pigs. Six structural proteins were selected and formulated into AP205 virus-like particles (VLPs). Additionally, replication-defective vesicular stomatitis virus (VSV)-based vaccine candidates expressing glycosylated CD2v and EP153R proteins were generated. Three groups of specific pathogen-free pigs were immunized with either VLP- or VSV-based vaccines and challenged with the virulent ASFV Georgia 2007 strain. Control groups included pigs immunized with the attenuated ASFV Estonia 2014 strain and a naïve group. Results: Most vaccine candidates induced detectable antibody responses against target ASFV proteins. However, neither VLP- nor VSV-based vaccines provided protection, as clinical scores, hematology, cytokine responses, and viremia levels were similar to those in the negative control group. In contrast, only the ASFV Estonia 2014 strain elicited a robust T-cell response and protective immunity. Conclusions: These findings highlight the challenges in identifying protective B-cell antigens of ASFV and emphasize the pivotal role of cellular immunity in mediating protection. Full article

African swine fever (ASF) is a contagious viral disease that causes severe economic losses in the global swine industry. Since its introduction to Vietnam in 2019, ASFV has evolved rapidly, with genotype II strains dominating initially and recombinant I/II variants emerging by 2023. Live attenuated vaccines (LAVs) have been developed and commercialized in Vietnam, including ASFV-G-ΔI177L, ASFV-G-ΔI177L/ΔLVR, and ASFV-G-ΔMGF, which confer homologous immune protection. Despite this, LAVs face challenges related to genetic stability, impossible protection against emerging recombinant strains, potential reversion to virulence, viral shedding, and safety in pregnant sows. ASFV’s ongoing evolution underscores the need for continuous genomic surveillance, evaluation of cross-protective efficacy, and implementation of biosecurity and DIVA strategies focused more on evaluating vaccine efficacy than safety. This review summarizes the current molecular epidemiology of ASFV in Vietnam after vaccines were licensed for use, the development and performance of commercial LAVs, and the practical challenges of their application in endemic settings, and provides insights for informed vaccine deployment and integrated ASF control strategies in rapidly evolving viral landscapes. Full article

The Carpathian Basin is a coherent biogeographic unit whose wildlife populations and pathogen dynamics are increasingly reshaped by administratively fragmented governance, land-use change and linear infrastructure. This review synthesizes evidence that the permeability patterns governing host movement also structure the transboundary exchange of genes and infections, creating a connectivity substrate for conservation genetics and One Health risk. Focusing on wild boar (Sus scrofa), red deer (Cervus elaphus), roe deer (Capreolus capreolus), fallow deer (Dama dama) and the expanding golden jackal (Canis aureus), we integrate population genetic inferences with wildlife epidemiology to examine how highways, border fences and asymmetric management (e.g., supplemental, feeding practices, hunting pressure and surveillance regimes) can generate biological asymmetries across boundaries. We highlight African swine fever as an emblematic disturbance in wild boar populations, discuss cervid risks including tick-borne pathogens and chronic wasting disease (CWD) preparedness and evaluate zoonotic threats associated with carnivore expansion (e.g., Echinococcus spp.). We propose a Carpathian Basin-level monitoring and data-sharing architecture, coupling harmonized passive surveillance, strategic active surveillance for priority pathogens, and standardized genetic marker panels supported by interoperable metadata. A Basin-scale One Health approach is a pragmatic prerequisite for the coordinated prevention, early detection and resilient management of cross-border epizootics and zoonotic threats. Full article

African swine fever (ASF), a highly contagious and lethal viral disease caused by the African swine fever virus (ASFV), poses a severe threat to the global swine industry. Recent outbreaks across Asia, Europe, and the Caribbean are exacerbating the challenge. Current control measures rely mainly on early detection, culling and strict biosecurity practices, underscoring the urgent need for a safe and effective vaccine. Since the mid-1960s, diverse vaccine strategies, including inactivated, subunit, DNA/mRNA, vectored, and live attenuated virus (LAV) vaccines, have been explored. Inactivated vaccines have consistently failed to confer protection due to insufficient functional antigen presentation and weak cellular immune activation. Subunit vaccines targeting single or multiple ASFV antigens have also shown limited success, often failing to induce sterile or long-lasting immunity. Among these approaches, LAV vaccines have demonstrated the greatest promise in eliciting robust and durable immune responses. However, major knowledge gaps remain regarding ASFV biology, ASFV–host interactions, ASFV immune evasion mechanisms, protective and cross-protective immunity, stable cell lines for LAV production, virulence reversion of LAVs, and the lack of harmonized standards for evaluating vaccine safety and efficacy, all of which impede the development of safe and broadly effective ASF vaccines. This narrative review summarizes recent advances in ASF vaccine research and highlights the critical obstacles that must be overcome to achieve successful ASF vaccine development. Full article

The accelerating frequency of emerging infectious diseases (EIDs) in livestock poses a significant threat to global food security, as well as to animal and public health. While wastewater-based surveillance (WBS) has advanced significantly for human health surveillance, its application to livestock production systems remains fragmented and lacks standardization. This review synthesizes current evidence on livestock wastewater-based surveillance (L-WBS) as an early-warning sentinel for emerging viral pathogens, evaluating their dynamics, economic impacts, biosecurity measures, and One Health implications. Existing studies demonstrate that L-WBS effectively detects emerging viral pathogens in agricultural effluent, swine manure, and municipal wastewater systems serving livestock regions, frequently preceding clinical outbreak recognition. We further conceptualized a multifactorial framework linking environmental drivers such as climate and ecological disruption and agricultural intensification to pathogen emergence dynamics. Economic assessments show substantial direct losses (approximately US$ 950 per H5N1-infected dairy cow and US$ 25.9 billion in African swine fever virus (ASFV)-related damages across China) alongside indirect costs from biosecurity implementation, workforce disruption, and supply-chain instability. We recommend prioritizing methodological standardization through unified sampling and extraction protocols, integration of next-generation sequencing for genomic surveillance, and cross-sectoral policy frameworks to operationalize L-WBS as a global early-warning infrastructure for mitigating zoonotic spillover and livestock-dependent community resilience. Full article

African swine fever (ASF) has been a persistent threat to Eurasian pig populations since its emergence in 2007. The disease has become endemic in numerous countries, including Poland, Germany, Romania, Hungary, Italy, the Philippines, and several others. Epidemiological data reveals that over 99% of outbreaks are attributed to a highly virulent hemadsorbing virus belonging to genotype II. Traditional genotyping methods, primarily relying on the B646L gene, have faced significant limitations in providing a comprehensive understanding of virus dissemination patterns. Previous attempts to identify a universal marker for tracking virus spread through analysis of the CVR locus of the B602L gene and the I73R/I329L locus failed to produce a coherent picture of the virus’s geographical distribution across Eurasia. To address these challenges, a comprehensive study was conducted involving the analysis of 250 ASFV isolates/strains from 25 countries across Europe and Asia between 2007 and 2024. This research led to the development of a novel sub-genotyping algorithm for ASFV genotype II. The study identified four topotypes: «CAU1», «EU1», «EU2», and «ASIA1». Within these topotypes, 31 genetic lineages were detected, each characterized by specific single-nucleotide polymorphisms (SNPs). Based on the comparison of two methods of sub-genotyping Eurasian ASFVs—the classification by Gallardo C. et al. (2023) based on genetic variations of 6 loci, and the proposed classification into topotypes and genetic lineages using whole-genomes—it was established that the multigenic approach has insufficient resolution. At the same time, significant differences were observed at the level of whole-genomes. The creation of a new spatiotemporal classification has significant applications in international surveillance of ASF outbreaks, local disease monitoring, and investigation of new infection cases. Full article

The regulatory mechanisms of collagen formation and cell adhesion pathways during African Swine Fever Virus (ASFV) infection remain poorly understood. This study aims to investigate whether ASFV manipulates these pathways by targeting host transcriptional regulators. Through weighted Kendall correlation analysis of transcription factor binding sites (TFBSs) in differentially expressed genes (DEGs) from the lung tissue of ASFV-recovered pigs, we identified SP2 and KLF6 as key transcription factors (TFs) associated with collagen synthesis and cell adhesion, respectively. Domain–domain interaction prediction, followed by Förster resonance energy transfer (FRET) assays, confirmed that the ASFV proteins R238L and R298L directly bind to the zf-C2H2 domains of SP2 and KLF6. Furthermore, overexpression of R238L and R298L in HeLa and 3D4/21 cells significantly downregulated SP2 and KLF6 target genes involved in these pathways. Our findings reveal a novel mechanism by which ASFV proteins R238L and R298L interfere with host transcription factors SP2 and KLF6, potentially disrupting collagen matrix integrity and cell adhesion to facilitate viral pathogenesis. Full article

This study investigated the genetic diversity and population structure of five Hainan indigenous pig breeds (147 individuals from 7 populations representing 5 breeds: 3 Duntou pig subpopulations (DT-DZ, DT-SJ, and DT-SG) and four additional breeds (Wuzhishan, Wenchang, Lingao, and Tunchang)) to address germplasm conservation needs driven by exotic crossbreeding, African swine fever, and inadequate genetic evaluation. After strict quality screening, we used 147 qualified samples for microsatellite genotyping and 104 samples for mtDNA D-loop sequencing. The analyses integrated 17 FAO-recommended microsatellite markers and mtDNA D-loop sequencing. In total, 15 out of 17 loci exhibited high polymorphism (PIC > 0.6), with Wuzhishan pigs exhibiting the highest genetic diversity (He = 0.666, I = 1.279). Pairwise Fst values indicated significant genetic differentiation among all populations (p < 0.05), and AMOVA attributed 87.32% of the genetic variation to within-population differences. Three complementary clustering methods (UPGMA, PCoA, and STRUCTURE with the optimal K value of 2 identified via the ΔK algorithm) divided the populations into two clades, clearly separating the Duntou subpopulations from other breeds. mtDNA D-loop sequencing of 104 individuals yielded a 1175 bp fragment, identifying 12 haplotypes and a high haplotype diversity (Hd = 0.688) low nucleotide diversity (π = 0.00193) pattern; Lingao pigs showed no genetic variation, while Duntou and Wuzhishan pigs had the highest Hd. NJ phylogenetic analysis indicated that Hainan pigs form an independent subclade within Chinese indigenous pigs, closely related to Luchuan pigs. These findings confirm the high overall genetic diversity and distinct population-level divergence in Hainan pigs, with Duntou pigs representing a unique lineage. This work provides a scientific basis for targeted conservation strategies, including prioritizing the conservation of Duntou and Wuzhishan pigs and restoring genetic variation in Lingao pigs. Full article