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Porcine epidemic diarrhea virus (PEDV) causes the third most important disease in the pig industry, after African swine fever and porcine reproductive and respiratory syndrome, and leads to illness or death of the entire litter, causing significant economic losses. In this study, three PEDV strains (HN-1, HN-2, and SC2023) were isolated from swine farms with suspected PEDV infections in Sichuan and Henan provinces. Phylogenetic analysis based on complete S gene sequences showed that all three strains belonged to the G2c subgroup. HN-1 adapted readily to cell culture, grew to a viral titer as high as 2 × 108 TCID50/mL in Vero cells, and caused the formation of large syncytia. We analyzed the amino acid sequence of the HN-1 isolate and found that its S1 subunit contained a three-amino-acid insertion (355KRL358). A seven-amino-acid-deletion (1377FEKVHVQ1383) in the S2 subunit resulted in the partial deletion of the endocytosis signal YxxΦ and the complete deletion of the endoplasmic reticulum retrieval signal (ERRS) KVHVQ in the cytoplasmic tail of the S protein. Consequently, HN-1 is predicted to be less pathogenic than its parent strain, an attribute that facilitates rapid cell-to-cell spread by enhancing syncytium formation. In addition, strain HN-1 was found to have the mutation 884–885SG→RR, which may favor adaptation to cell culture by providing new trypsin cleavage sites. These results suggest that HN-1 is a G2c subtype variant that adapts well to cell culture and can be used to study the adaptive mechanisms of PEDV and develop attenuated vaccines. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) is a high-consequence transboundary animal disease caused by African swine fever virus (ASFV). Given that vaccines are not widely available, ASFV detection, including by molecular and serologic assays, is paramount to efficacious control and mitigation of ASF. ASFV-specific antibodies can be detected as early as 7–10 d postinfection in infected animals and may persist for several months or longer. Accurate detection of ASFV-specific antibody is critical for the identification of chronically infected, subclinically infected, or recovered animals. ELISAs are commonly used for the rapid screening of large numbers of animals for ASFV antibodies. The World Organisation for Animal Health recommends that ELISA-positive results should be confirmed with a second serologic method, such as an indirect immunofluorescent assay, indirect immunoperoxidase test (IPT), or immunoblot test. Commercial kits are not available for those tests. We developed and validated an in-house IPT by using a currently circulating genotype II ASFV strain as antigen. The sensitivity and specificity of the in-house IPT are comparable to the reference IPT developed by an international ASFV reference laboratory and superior to a commercial blocking ELISA. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) is endemic to Uganda and causes annual outbreaks. Some pigs survive these outbreaks and remain asymptomatic but are African swine fever virus (ASFV) positive. The potential heritability and genetic disparities in disease susceptibility among Ugandan pigs are not fully understood. In a 12-year study, whole blood and tissue samples were collected from 212 pigs across 19 districts in Uganda. Polymerase chain reaction (PCR) assays were used to determine ASFV infection status and genotyping was completed using a commercial porcine array. The point prevalence of ASF was calculated for each district, and breed composition origins were quantified for the sampled pigs by implementing established ancestry analyses. Genome-wide associated studies (GWAS) were conducted using all available domestic swine samples (full study population; n = 206) as well as a reduced dataset (farm-level study population; n = 129). This study revealed a greater number of ASFV-positive pigs in border districts than in non-border districts, a high level of admixture among domestic pigs sampled from Ugandan smallholder farms, and 48 loci that were associated with ASFV infection status. The discovery of 48 significant SNPs and 28 putative candidate genes may imply the possibility of heritability for resistance to ASFV. However, additional investigations in ASFV-endemic regions are required to fully elucidate the heritability of ASFV susceptibility among surviving pigs in Uganda. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) is caused by Asfivirus and has become one of the most important diseases of swine in recent years. ASF was an endemic disease of the sub-Saharan Africa but later spread to various parts of the world. The infection in ticks and wild swine, alongside global pork trade, drives its spread and persistence. Once introduced to an area, the disease is difficult to eliminate due to sylvatic, domestic, and tick-swine transmission cycles. Because of the existence of various modes of transmission of the ASF virus, biosecurity measures have not been very successful. The line of treatment is not of much use and the outcome of this disease is usually fatal. The prognosis or the recovery of the animal depends on the virulence of the strain involved. Development of vaccines has been attempted but to date has not been very successful. This review focuses on the basic context of ASF, the challenges associated with it, and the options that might be available to prevent its occurrence which includes the different vaccine development strategies tried and tested till now. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) poses a significant threat to domestic pigs and wild boar (Sus scrofa) populations, with the current epidemiological situation more critical than ever. The disease has spread across five continents, causing devastating losses in the swine industry. Although extensive research efforts are ongoing to develop an effective and safe vaccine, this goal remains difficult to achieve. Among the potential vaccine candidates, live attenuated viruses (LAVs) have emerged as the most promising option due to their ability to provide strong protection against experimental challenges. However, ASF virus (ASFV) is highly diverse, with genetic and phenotypic variations across different isolates, which differ in virulence. This study highlights the limitations of a natural LAV strain (Lv17/WB/Rie1), which showed partial efficacy against a highly virulent and partially heterologous isolate (Arm07; genotype II). However, the LAV's effectiveness was incomplete when tested against a more phylogenetically distant virus (Ken06.Bus; genotype IX). These findings raise concerns about the feasibility of developing a universal vaccine for ASFV in the near future, emphasizing the urgent need to assess the protective scope of LAV candidates across different ASFV isolates to better define their limitations. [ABSTRACT FROM AUTHOR]

Background: Gut microbes are important regulators of host health and can also function as disease indicators. Lactiplantibacilllus plantarum(L. plantarum)used as express and delivery vaccines for mucosal immunity have been shown to activate specific immune responses in numerous studies. Results: The interaction between recombinant L. plantarum and the gut microbiota was investigated in this study. The results indicated a change in the amount of gut OTU by recombinant L. plantarum. Recombinant L. plantarum dramatically boosted the species diversity of gut bacteria based on the Shannon-Wiener index. Beta diversity analysis showed that microbial structure was changed by recombinant L. plantarum. Furthermore, recombinant NC8 L. plantarum expressing a fusion between the P14.5 protein of the African swine fever virus and IL-33 enhanced the functions of gut bacteria in metabolism and immune regulation. Increased levels of IgG and IgG1 in serum and sIgA in feces, as well as enrichment of CD4+ T cells and IgA+ B cells, indicated that the gut microbiota exerted an immunomodulatory role when mediated by recombinant L. plantarum. Conclusions: These results revealed that recombinant L. plantarum exerted its potential role in the gut microbiota and gut immunity.These fndings contribute to a broader understanding and utilization of L. plantarum bacteria in various therapeutic applications. [ABSTRACT FROM AUTHOR]

Key Points: Question: How has the widescale distribution of rapid diagnostic tests for malaria across sub-Saharan African countries affected febrile illness management and mortality for children younger than 5 years of age? Findings: Increasing distribution of rapid diagnostic tests for malaria was associated with increased blood testing, use of antimalarial drugs, and antibiotic use and modestly improved child survival. The greatest benefits occurred in areas with a high prevalence of malaria. Meaning: The distribution of rapid diagnostic tests for malaria was associated with changes in pediatric febrile illness management and improved survival. Importance: A prompt malaria diagnosis is crucial for the management of children with febrile illness in sub-Saharan African countries, where malaria remains a leading cause of mortality among children younger than 5 years of age. The development and distribution of point-of-care rapid diagnostic tests (RDTs) for malaria has transformed practice, but limited systematic evidence exists on how malaria RDTs have affected the management of febrile illness and mortality for children younger than 5 years of age across sub-Saharan Africa countries. Objective: To evaluate the association between the distribution of malaria RDTs and the management of febrile illness and mortality among children younger than 5 years of age in sub-Saharan African countries. Design, Setting, and Participants: This quasi-experimental study used a novel dataset linking malaria RDT distribution to 165 nationally representative household surveys across 35 sub-Saharan African countries with mortality data. The sample comprised approximately 3.9 million child-year observations and approximately 260 000 febrile illness episodes in children younger than 5 years of age between 2000 and 2019. Main Outcomes and Measures: Fixed-effects linear probability models were used to analyze the association between variation in malaria RDTs distributed per child younger than 5 years of age (by country per year) and blood testing, antimalarial drug use, antibiotic use, use of symptomatic treatments, and mortality rates. Variation in the effects of testing and treatment was also assessed across the sub-Saharan African countries that had varying prevalence of malaria. Results: The mortality sample included 1 317 866 children and the fever sample included 256 292 children. The mean age of the children with febrile illness was 2.4 years (SD, 1.3 years) and 49% were female. Each additional malaria RDT distributed per child younger than 5 years of age was associated with an increase of 3.5 percentage points (95% CI, 3.2-3.8 percentage points) in blood testing, an increase of 1.5 percentage points (95% CI, 1.2-1.8 percentage points) in the use of antimalarial drugs, an increase of 0.4 percentage points (95% CI, 0.1-0.6 percentage points) in antibiotic use, and a decrease of 0.4 percentage points (95% CI, 0.1-0.8 percentage points) in the use of treatments for symptoms. Each additional malaria RDT distributed per child younger than 5 years of age was associated with a reduction in child mortality of 0.34 deaths per 1000 child-years (95% CI, 0.15-0.52 deaths per 1000 child-years). The effects of malaria RDT distribution on medication use and child mortality varied across prevalence settings (low vs high) for malaria; there were survival improvements only in areas that had a high prevalence of malaria. Conclusions and Relevance: Increasing distribution of malaria RDTs was associated with increased blood testing, increased use of antimalarial drugs, and modestly improved survival in children younger than 5 years of age in sub-Saharan African countries. However, malaria RDTs were associated with increases in the rates of antibiotic use that were already high, suggesting that more comprehensive approaches to case management of febrile illness are needed. This quasi-experimental study evaluates the association between the distribution of rapid diagnostic tests for malaria and the management of febrile illness and mortality among children younger than 5 years of age in sub-Saharan African countries. [ABSTRACT FROM AUTHOR]

African swine fever (ASF), caused by the African swine fever virus (ASFV), is a deadly, highly contagious disease in both domestic pigs and wild boar. With mortality up to 100%, the disease has been making a serious impact on the swine industry worldwide. Because no effective antiviral treatment has been observed, proactive prevention such as vaccination remains the key to controlling the outbreak. In the pursuit of expediting vaccine development, our current work has made the first report for heterologous production of the viral outer envelope glycoprotein CD2v extracellular domain (CD2v ED), a proposed promising vaccine antigen candidate in the "green" synthetic host Nicotiana benthamiana. Protein oligomerization strategies were implemented to increase the immunogenicity of the target antigen. Herein, the protein was expressed in oligomeric forms based on the C-terminally fused GCN4pII trimerization motif and GCN4pII_TP oligomerization motif. Quantitative western blot analysis showed significantly higher expression of trimeric CD2v ED_GCN4pII with a yield of about 12 mg/100 g of fresh weight, in comparison to oligomeric CD2v ED_GCN4pII_TP, revealing the former is the better choice for further studies. The results of purification and size determination by size exclusion chromatography (SEC) illustrated that CD2v ED_GCN4pII was successfully produced in stable oligomeric forms throughout the extraction, purification, and analysis process. Most importantly, purified CD2v ED_GCN4pII was demonstrated to induce both humoral and cellular immunity responses in mice to extents equivalent to those of the live attenuated vaccine ASFV-G-∆I177L, suggesting it as the potential subunit vaccine candidate for preventing ASFV. [ABSTRACT FROM AUTHOR]

ASFV C315R is homologous to the transcription factor TFIIB of large unclassified DNA viruses, and H359L is identical to the subunit 3 (RPB3) of eukaryotic RNA polymerase II. The C315R and H359L may play an important role in ASFV replication and transcription. Here, we evaluated the biological function of the C315R and H359L genes during virus replication in vitro and during infection in pigs. Results showed that C315R and H359L are highly conserved among ASFV genotype II strains; quantitative PCR (qPCR) and western blotting analyses revealed that C315R and H359L are early transcribed genes prior to viral DNA replication, but their protein expression is delayed. The immunofluorescence and western blotting analysis revealed that both proteins localized in the cell cytoplasm and nucleus at 24 h post infection, however, pH359L was mainly detected in the cell cytoplasm. Furthermore, overexpression of pH359L in MA104 cells significantly increased viral titer, RNA transcription levels, and viral protein expression levels, while overexpression of pC315R slightly enhanced ASFV replication. In contrast, siRNA targeting ASFV-H359L or C315R reduced replication efficiency in porcine macrophage culture compared to the parent ASFV-CN/SC/2019, demonstrating that C315R and H359L genes are necessary for ASFV replication. Finally, the functional role of C315R or H359L on PKR and eIF2a phosphorylation status and SG formation, as well as cytokine production were evaluated. These studies demonstrated that C315R and H359L are involved in virus replication processes in swine and play important roles in ASFV replication. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) is a devastating disease caused by African swine fever virus (ASFV) and leads to significant economic losses in the pig farming industry. Given the absence of an effective vaccine or treatment, the mortality rate of ASF is alarmingly close to 100%. Consequently, the ability to rapidly and accurately detect ASFV on site and promptly identify infected pigs is critical for controlling the spread of this pandemic. The dynamics of the ASF virus load and antibody response necessitate the adoption of various detection strategies at different stages of infection, a topic that has received limited attention to date. This review offers detailed guidance for choosing appropriate ASF diagnostic techniques tailored to the clinical manifestations observed from the acute to chronic phases, including asymptomatic cases. We comprehensively summarize and evaluate the latest advancements in ASFV detection methods, such as CRISPR-based diagnostics, biosensors, and microfluidics. Additionally, we address the challenges of false negatives or positives due to ASF variants or the use of injected live attenuated vaccines. This review provides an exhaustive list of diagnostic tests suitable for detecting each stage of symptoms and potential target genes for developing new detection methods. In conclusion, we highlight the current challenges and future directions in ASFV detection, underscoring the need for continued research and innovation in this field. [ABSTRACT FROM AUTHOR]

Objectives: The studies on the spread of major animal diseases and its evolution of public opinion are of great significance to the improvement of epidemic prevention and public opinion guidance. With the development of Web 2.0 technology and the popularity of smart phones, various forms of social media platforms become important channels for obtaining, sharing and discussing hot topics. A large number of texts with geographical location information are generated, which have provided a new way for the research of animal epidemic and other emergencies. Methods: Taking Sina microblog data during African swine fever (ASF) spread in our country from 2018 to 2019 as the case study, the objective of this work is to establish the spread spatiotemporal characteristics analysis and public opinion mining model. First, the Mann-Kendall mutation detection method is introduced to objectively divide the epidemic transmission cycle and investigate the spatial distribution characteristics of different stages. Then, the latent Dirichlet allocation theme clustering model is used to describe the evolution of public opinion topics among different ASF epidemic stages. Finally, the primary factors influencing public opinion attention are explored based on the geographical detector method. Results: The results show that the spread of ASF in China showed a trend of spreading from northeast to southwest, and experienced four stages: Incubation, outbreak, fluctuation and recession. Conclusions: At each stage, public opinion around outbreak itself and the specific theme is derived, and with the development of epidemic derivative subject is more abundant, popular sentiment also from at each stage. Public opinion around outbreak itself and the specific derivative topics, and derivative topics become more abundant with the development of epidemic, public sentiment also gradually changes from negative to positive. Regional awareness of ASF is strongly influenced by pork consumption and production, rather than by local education and urbanization levels. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) is an acute, highly hemorrhagic viral disease in domestic pigs and wild boars. The disease is caused by African swine fever virus, a double stranded DNA virus of the Asfarviridae family. ASF can be classified into 25 different genotypes, based on a 478 bp fragment corresponding to the C-terminal sequence of the B646L gene, which is highly conserved among strains and encodes the major capsid protein p72. The C-terminal end of p72 has been used as a PCR target for quick diagnosis of ASF, and its characterization remains the first approach for epidemiological tracking and identification of the origin of ASF in outbreak investigations. Recently, a new classification of ASF, based on the complete sequence of p72, reduced the 25 genotypes into only six genotypes; therefore, it is necessary to have the capability to sequence the full-length B646L gene (p72) in a rapid manner for quick genotype characterization. Here, we evaluate the use of an amplicon approach targeting the whole B646L gene, coupled with nanopore sequencing in a multiplex format using Flongle flow cells, as an easy, low cost, and rapid method for the characterization and genotyping of ASF in real-time. [ABSTRACT FROM AUTHOR]

Rapid and reliable detection method for African swine fever virus (ASFV) is proposed by surface-enhanced Raman spectroscopy (SERS). The ASFV target DNA can be specifically captured by sandwich hybridization between nanomagnetic beads and a SERS probe. Experimental results show that the significant Raman signal of the SERS probe with gold nanoparticles and a molecular reporter DTNB (5,5′-dimercapto-bis (2-nitrobenzoic acid)) can be adopted for detecting the hybridization chain reaction of ASFV DNA. The advantage of the SERS sandwich hybridization assay is the large response range from the single molecule level to 108 copies per mL, which not only can overcome the tedious time required for the amplification reaction but also provides a comparative method to polymerase chain reaction. Furthermore, real samples of African swine fever virus were detected from different subjects of swine fever virus including porcine reproductive respiratory syndrome virus and Japanese encephalitis virus. The proposed biosensor method can rapidly detect ASFV correctly within 15 min as a simple, convenient, low-cost detection approach. The biosensor can be used as a platform for the determination in biological, food, and environmental analytical fields. [ABSTRACT FROM AUTHOR]

This study described the results of a surveillance program monitoring circulation of influenza A viruses among domestic pigs (Sus domesticus) in Kazakhstan during 2018--2021. PCR data derived from 2,513 samples (nasopharyngeal swabs) collected from swine on large pig complexes and peasant farms located in different regions of Kazakhstan revealed that about 5% of samples were positive for influenza A virus RNA. This result suggested low levels of influenza A virus circulation in Kazakhstan. Subtyping of a set of samples revealed that the main strains circulating in 2018--2019 were A/H1N1 and A/H3N2. Surveillance conducted in 2020--2021 identified only A/H1N1 viruses in swine. The PCR data were confirmed by isolation of six strains: five influenza A/H1N1 viruses and one A/H3N2 virus. [ABSTRACT FROM AUTHOR]

The African swine fever virus (ASFV) causes fatal disease in pigs and is currently spreading globally. Commercially safe vaccines are urgently required. Aiming to generate a novel live attenuated vaccine (LAV), a recombinant ASFV was generated by deleting the viral O174L (PolX) gene. However, during in vitro generation, an additional spontaneous deletion of genes belonging to the multigene families (MGF) occurred, creating a mixture of two viruses, namely, Arm-ΔPolX and Arm-ΔPolX-ΔMGF. This mixture was used to inoculate pigs in a low and high dose to assess the viral dynamics of both populations in vivo. Although the Arm-ΔPolX population was a much lower proportion of the inoculum, in the high-dose immunized animals, it was the only resulting viral population, while Arm-ΔPolX-ΔMGF only appeared in low-dose immunized animals, revealing the role of deleted MGFs in ASFV fitness in vivo. Furthermore, animals in the low-dose group survived inoculation, whereas animals in the high-dose group died, suggesting that the lack of MGF and PolX genes, and not the PolX gene alone, led to attenuation. The two recombinant viruses were individually isolated and inoculated into piglets, confirming this hypothesis. However, immunization with the Arm-ΔPolX-ΔMGF virus did not induce protection against challenge with the virulent parental ASFV strain. This study demonstrates that deletion of the PolX gene alone neither leads to attenuation nor induces an increased mutation rate in vivo. [ABSTRACT FROM AUTHOR]

The hepatitis E virus (HEV) has become increasingly important in recent years in terms of risk for public health, as the main causative agent of acute viral hepatitis. It is a foodborne disease transmitted to humans through the consumption of contaminated water or contaminated food. Human-to-human transmission is sporadic and is linked to transfusions or transplants. The main reservoirs of the hepatitis E virus are domestic pigs and wild boars, although, compared to pigs, wild boars represent a lesser source of risk since their population is smaller and the consumption of derived products is more limited. These peculiarities often make the role of the wild boar reservoir in the spread of the disease underestimated. As a public health problem that involves several animal species and humans, the management of the disease requires an interdisciplinary approach, and the concept of "One Health" must be addressed. In this direction, the present review intends to analyze viral hepatitis E, with a particular focus on wild boar. For this purpose, literature data have been collected from different scientific search engines: PubMed, MEDLINE, and Google scholar, and several keywords such as "HEV epidemiology", "Extrahepatic manifestations of Hepatitis E", and "HEV infection control measures", among others, have been used. In the first part, the manuscript provides general information on the disease, such as epidemiology, transmission methods, clinical manifestations and implications on public health. In the second part, it addresses in more detail the role of wild boar as a reservoir and the implications related to the virus epidemiology. The document will be useful to all those who intend to analyze this infectious disease from a "One-Health" perspective. [ABSTRACT FROM AUTHOR]

Cell-passage-adapted strains of African swine fever virus (ASFV) typically exhibit substantial genomic alterations and attenuated virulence in pigs. We have indicated that the HEK293T cells-adapted ASFV strain underwent genetic alterations and the I7L gene in the right variable region was deleted compared with the ASFV HLJ/2018 strain (ASFV-WT). A recent study has revealed that the deletion of the I7L-I11L genes results in attenuation of virulent ASFV in vivo, but the underlying mechanism remains largely unknown. Therefore, we hypothesized that the deletion of the I7L gene may be related to the pathogenicity of ASFV in pigs. We generated the I7L gene-deleted ASFV mutant (ASFV-ΔI7L) and found that the I7L gene deletion does not influence the replication of ASFV in primary porcine alveolar macrophages (PAMs). Using transcriptome sequencing analysis, we identified that the differentially expressed genes in the PAMs infected with ASFV-ΔI7L were mainly involved in antiviral immune responses induced by interferon gamma (IFN-γ) compared with those in the ASFV-WT-infected PAMs. Meanwhile, we further confirmed that the I7L protein (pI7L) suppressed the IFN-γ-triggered JAK-STAT signaling pathway. Mechanistically, pI7L interacts with STAT1 and inhibits its phosphorylation and homodimerization, which depends on the tyrosine at position 98 (Y98) of pI7L, thereby preventing the nuclear translocation of STAT1 and leading to the decreased production of IFN-γ-stimulated genes. Importantly, ASFV-ΔI7L exhibited reduced replication and virulence compared with ASFV-WT in pigs, likely due to the increased production of IFN-γ-stimulated genes, indicating that pI7L is involved in the virulence of ASFV. Taken together, our findings demonstrate that pI7L is associated with pathogenicity and antagonizes the IFN-γ-triggered JAK-STAT signaling pathway via inhibiting the phosphorylation and homodimerization of STAT1 depending on the Y98 residue of pI7L and the SH2 domain of STAT1, which provides more information for understanding the immunoevasion strategies and designing the live attenuated vaccines for ASF. Author summary: Deletion of pivotal virulence-associated genes to develop live attenuated African swine fever (ASF) vaccines is considered as a promising strategy. Our previous research demonstrated that the I7L gene of the HEK293T cells-adapted African swine fever virus (ASFV) strain was completely lost, and the deletion of the I7L-I11L genes resulted in ASFV attenuation, suggesting that the deletion of the I7L gene seemed to be related to the pathogenicity of ASFV in pigs. In this study, we investigated the function of the I7L protein (pI7L) in the ASFV replication cycle in vitro as well as evaluated the pathogenicity of the I7L gene-deleted ASFV mutant in vivo. Our results showed that the deletion of I7L gene does not influence the replication of ASFV in primary porcine alveolar macrophages (PAMs). However, pI7L is involved in the virulence of ASFV, and directly interacts with STAT1 and antagonizes the IFN-γ-triggered JAK-STAT signaling pathway via inhibiting the phosphorylation and homodimerization of STAT1 depending on the tyrosine at position 98 of pI7L and the SH2 domain of STAT1. This study not only facilitates the understanding of ASFV immunoevasion strategies, but also provides a novel target for the development of live attenuated vaccines against ASF. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) is a highly contagious and lethal disease of swine caused by African swine fever virus (ASFV), and the mortality rate caused by virulent stains can approach 100%. Many ASFV viral proteins suppress the interferon production to evade the host's innate immune responses. However, whether ASFV MGF360-4L could inhibit type I interferon (IFN-I) signaling pathway and the underlying molecular mechanisms remain unknown. Our study, indicated that ASFV MGF360-4L could negatively regulates the cGAS-STING mediated IFN-I signaling pathway. Overexpressing ASFV MGF360-4L could inhibit the cGAS/STING signaling pathway by inhibiting the interferon-b promoter activity, which was induced by cGAS/STING, TBK1, and IRF3-5D, and further reduced the transcriptional levels of ISG15, ISG54, ISG56, STAT1, STAT2, and TYK2. Confocal microscopy and immunoprecipitation revealed that MGF360-4L colocalized and interacted with IRF3, and WB revealed that ASFV MGF360-4L suppressed the phosphorylation of IRF3. 4L-F2 (75-162 aa) and 4L-F3 (146-387 aa) were the crucial immunosuppressive domains and sites. Altogether, our study reveals ASFV MGF360-4L inhibited cGAS-STING mediated IFN-I signaling pathways, which provides insights into an evasion strategy of ASFV involving in host's innate immune responses. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) is a highly fatal hemorrhagic disease affecting domestic pigs caused by African swine fever virus (ASFV). Genetic analysis of ASFV isolates to date has identified 24 geographically related genotypes with various subgroups, but only genotype I and II ASFVs have been reported outside Africa. ASFV genotype II and genotype I viruses were reported in China in 2018 and 2021, respectively. In this study, unique and highly conserved noncoding regions were found between MGF_505-9R and MGF_505-10R in the 188 genomes of ASFV genotypes I and II. A pair of primers was designed on the basis of this region. By optimizing the reaction system and conditions, a SYBR Green I fluorescence PCR assay that can distinguish between ASFV genotypes I and II was established, and the sensitivity, reproducibility and specificity were evaluated. The detection limit was 1 TCID50/0.1 mL for both genotypes, with no cross-reactivity observed with other common pig pathogens. The intra- and interbatch variation coefficients were both less than 1.2%. Clinical sample detection analysis revealed 47 positive cases out of 100, including 3 for genotype I and 44 for genotype II, aligning with results from the WOAH-recommended and national standard methods. The method developed in this study allows for the differentiation of ASFV genotypes I and II without the need for genome sequencing, offering a convenient and rapid approach for ASFV detection and genotype identification. [ABSTRACT FROM AUTHOR]

African swine fever virus (ASFV) poses serious threats to the global swine industry, food safety, and the economy. Since August 2018, different types of ASFVs have successively emerged in China, making ASF diagnostics more challenging. The highly virulent genotype I recombinant virus has gradually become the prevalent dominant strain and is identified by sequencing several of its genes, which is time‐consuming and expensive. Here, we developed a triplex real‐time quantitative PCR (qPCR) assay based on the ASFV B646L, X64R, and MGF_360‐14L genes to differentiate highly virulent genotype I recombinant viruses from low‐virulence genotype I and genotype II viruses in China. This method has high sensitivity and a limit of detection of 10 copies/reaction for standard plasmids, as well as good specificity without cross‐reactions with the viral nucleic acids of porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV), pseudorabies virus (PRV), porcine circovirus 2 (PCV 2), porcine circovirus 3 (PCV 3), porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), or porcine rotavirus (PoRV). Importantly, triplex qPCR can be used to quickly and accurately evaluate clinical samples and cell cultures infected with highly virulent genotype I virus, low‐virulence genotype I virus, or genotype II virus. Thus, triplex qPCR provides an alternative tool for ASF surveillance in China. [ABSTRACT FROM AUTHOR]

The Ornithodoros moubata (Om) soft tick, a vector for diseases like tick‐borne human relapsing fever and African swine fever, poses challenges to conventional control methods. With diminishing insecticide efficacy, harnessing the tick's microbiota through innovative approaches like microbiota‐driven vaccination emerges as a promising strategy for sustainable and targeted disease control. This study investigated the intricate relationship between Pseudomonas, a keystone taxon in the Om microbiome, and its impact on tick fitness, microbiome structure and network dynamics. Utilizing in silico analyses and empirical vaccination experiments, the role of Pseudomonas within microbial networks in the tick midguts (MG) and salivary glands (SG) of Om was studied. Additionally, the consequences of anti‐microbiota vaccines targeting Pseudomonas and Lactobacillus on tick fitness, microbiome diversity and community assembly were explored. The result of the study shows that in Om, Pseudomonas plays a central role in microbial networks, influencing keystone species despite being categorized as peripheral (interacting with 47 different taxa, 13 of which are keystone species). Anti‐microbiota vaccination targeting Pseudomonas and Lactobacillus yields distinct effects on tick fitness, with Pseudomonas vaccination significantly impacting female tick survival, while Lactobacillus significantly reduced oviposition and fertility. Microbiome changes post‐vaccination reveal diversity alterations, emphasizing the impact of vaccine choice. Community assembly dynamics and network robustness analyses highlight Pseudomonas' pivotal role, in influencing topological features and network resilience. The findings of the study provide comprehensive insights into the intricate dynamics of Om microbial networks and the potential of targeted microbiota‐driven vaccines for tick control. [ABSTRACT FROM AUTHOR]

Simple Summary: Wildlife in human-dominated landscapes often faces a range of disturbances that can alter their natural behaviors. Wild boar (Sus scrofa) populations are increasing across Europe, raising concerns about ecological impacts and the spread of diseases such as African swine fever (ASF). This research focuses on the behavioral adaptations of wild boars in response to specific human disturbances. Utilizing advanced biologging technologies, specifically accelerometer and magnetometer combined with dead reckoning methods, fifteen wild boars in a suburban forest near Prague were monitored over a period from February 2020 to July 2021. This study provides insights into the wild boar's resilience, revealing that while the animals are inclined to flee when near disturbances, they predominantly remain in a resting state otherwise. Their most common reaction was to continue resting. These observations underscore the potential role of disturbance management in controlling the spread of zoonotic diseases such as African swine fever (ASF) within wild boar populations. Currently, African swine fever (ASF), a highly fatal disease has become pervasive, with outbreaks recorded across European countries, leading to preventative measures to restrict wild boar (Sus scrofa L.) movement, and, therefore, keep ASF from spreading. This study aims to detail how specific human activities—defined as "car", "dog", "chainsaw", and "tourism"—affect wild boar behavior, considering the disturbance proximity, and evaluate possible implications for wild boar management in ASF-affected areas. Wild boar behavior was studied using advanced biologging technology. This study tracks and analyzes wild boar movements and behavioral responses to human disturbances. This study utilizes the dead reckoning method to precisely reconstruct the animal movements and evaluate behavioral changes based on proximity to disturbances. The sound of specific human activities was reproduced for telemetered animals from forest roads from different distances. Statistical analyses show that wild boars exhibit increased vigilance and altered movement patterns in response to closer human activity, but only in a small number of cases and with no significantly longer time scale. The relative representation of behaviors after disruption confirmed a high instance of resting behavior (83%). Running was the least observed reaction in only 0.9% of all cases. The remaining reactions were identified as foraging (5.1%), walking (5.0%), standing (2.2%), and other (3.8%). The findings suggest that while human presence and activities do influence wild boar behavior, adherence to movement restrictions and careful management of human activity in ASF-infected areas is not a necessary measure if human movement is limited to forest roads. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigated the genetic attributes of the Jiangshan black pig conservation population, with a specific focus on genetic diversity, family structure, and levels of inbreeding. The results provide significant insights for the management and conservation of a pig population with limited numbers. The study proposes the use of genomic data by breeders to improve breeding practices, especially by taking into account familial relationships. Suggestions include maintaining an equitable distribution of male and female pigs within each family and choosing individuals with a kinship coefficient lower than 0.1 for breeding purposes. The Jiangshan black pig is an indigenous pig breed in China, renowned for its superior meat quality and adaptability to roughage. However, the population of Jiangshan black pigs has dwindled due to the introduction of cosmopolitan pig breeds and the outbreak of African swine fever, putting them at risk of extinction. To offer insights into the conservation and breeding of Jiangshan black pigs, this study involved 118 Jiangshan black pigs as the research subjects and employed the Zhongxin-1 Porcine Breeding Array PLUS chip to detect whole-genome SNPs. Additionally, various software tools were utilized to accurately analyze the genetic diversity, phylogenetic relationship, inbreeding coefficient, and pedigree structure of the Jiangshan black pig conservation population. The findings indicated that the effective population size (Ne) of the Jiangshan black pig was 4.9, with an average inbreeding coefficient of 0.253 within the population. A genetic relationship analysis identified that the 16 male pigs were clustered into four families, and the 100 female pigs were also assigned to these familial groups. Furthermore, two female pigs were classified as "other" due to their distant genetic relatedness to all the males. These results contribute to a better understanding of the current status of the conservation of the Jiangshan black pig population and offer a theoretical foundation for the development of conservation strategies. [ABSTRACT FROM AUTHOR]

Background: African swine fever (ASF) poses a threat to the global pig industry, leading to significant economic losses and widespread disruptions in pig farming and associated sectors. In September 2023, the first case of ASF in Swedish wild boar triggered immediate responses from authorities, including the establishment of restricted zones and culling measures. A new ASF certification programme for pig herds was initiated to improve biosecurity and proactive disease management. This survey aimed to assess the sentiments and actions of Swedish pig farmers six months post-outbreak, particularly regarding biosecurity measures. Such information is important to improve preparedness for future disease threats. A questionnaire was distributed to members of the Swedish pig producers' organisation. Results: A total of 113 farmers responded (response rate 27%), with the majority considering the risk of ASF reappearing in Sweden as high. The estimated cost for connecting the farms to the ASF certification programme varied greatly, with a majority identifying cost as a substantial hurdle. While many farmers sought biosecurity advice from veterinarians, 43% had not implemented suggested measures. Over one third had not received concrete measures that would fit their farms, and 14% had not received any biosecurity advice from veterinarians at all. Discussions among farmers emphasized concerns about ASF outbreaks, transmission mechanisms, and regulatory compliance, highlighting the importance of ongoing communication and knowledge exchange to address the challenges posed by ASF effectively. Additionally, participants also mentioned the role of dense wild boar populations and shortcomings in municipal food waste management as important risk factors. Conclusions: The responding farmers expressed widespread concern about new ASF outbreaks. A majority identified cost as a substantial hurdle for joining the ASF certification programme. While many farmers consulted veterinarians for advice on biosecurity, a significant number had yet to implement suggested measures and one third had not received specific guidance suitable for their farms. Stakeholder conversations highlighted concerns about ASF outbreaks, transmission, and compliance. They also discussed the role of dense wild boar populations and issues with municipal food waste management as significant risk factors for ASF. [ABSTRACT FROM AUTHOR]

Introduction: African swine fever (ASF) is a lethal and highly contagious transboundary animal disease with the potential for rapid international spread. In the absence of a widely available and definitively proven vaccine, rapid and early detection is critical for ASF control. The quick and user-friendly lateral flow assay (LFA) can easily be performed by following simple instructions and is ideal for on-site use. This study describes the development and validation of two LFAs for the rapid detection of ASF virus (ASFV) in pig serum. Methods: The highly immunogenic antigens (p30 and p72) of ASFV Georgia 2007/1 (genotype II) were expressed in plants (Nicotiana benthamiana) and were used to immunize BALB/c mice to generate specific monoclonal antibodies (mAbs) against the p30 and p72 proteins. mAbs with the strongest binding ability to each protein were used to develop p30_LFA and p72_LFA for detecting the respective ASFV antigens. The assays were first evaluated using a spike-in test by adding the purified p30 or p72 protein to a serum sample from a healthy donor pig. Further validation of the tests was carried out using serum samples derived from experimentally infected domestic pigs, field domestic pigs, and feral pigs, and the results were compared with those of ASFV real-time PCR. Results: p30_LFA and p72_LFA showed no cross-reaction with common swine viruses and delivered visual results in 15  min. When testing with serially diluted proteins in swine serum samples, analytical sensitivity reached 10  ng/test for p30_LFA and 20  ng/test for p72_LFA. Using real-time PCR as a reference, both assays demonstrated high sensitivity (84.21% for p30_LFA and 100% for p72_LFA) with experimentally ASFV-infected pig sera. Specificity was 100% for both LFAs using a panel of PBS-inoculated domestic pig sera. Excellent specificity was also shown for field domestic pig sera (100% for p30_LFA and 93% for p72_LFA) and feral pig sera (100% for both LFAs). Conclusion: The results obtained in this study suggest that p30_LFA and p72_ LFA hold promise as rapid, sensitive, user-friendly, and field-deployable tools for ASF control, particularly in settings with limited laboratory resources. [ABSTRACT FROM AUTHOR]

The French National Animal Health Surveillance Platform (NAHSP) was created in 2011. This network of animal health stakeholders was set up to improve surveillance efficiency for all health risks that threaten animal health, as well as zoonoses affecting human health. The NAHSP steering committee decides on the strategies and program of activities. It is composed of 11 institutions from both public and private sectors (policy-makers, scientific institutions, and representatives of farmers, veterinarians, hunters, and laboratories). A coordination teamguarantees the implementation of the programand facilitates the activities of different working groups (WGs). Each WG is composed of technical experts with scientific, legal, and field knowledge from the sectors of animal health (livestock, companion animals, and wildlife), human health, and environmental health. Some WGs focus on a specific disease or health indicator, such as African swine fever or cattle mortality, while others cover cross-cutting topics, such as epidemic intelligence (EI), or specialize in aiding epidemiological investigations, such as the Q fever WG. The NAHSP stands out for its innovative approach because it is based on the concepts of consensus-building among participants, fostering collaboration, and embracing interdisciplinarity. Each proposal designed to improve surveillance is jointly developed by all the stakeholders involved, thereby ensuring its sustainability and acceptability among stakeholders. This process also has added value for decision-makers. As a pioneer platform, the NAHSP inspired the creation of two additional national surveillance platforms in 2018, one for plant health and the other for food chain safety. Both are organized in the same way as the NAHSP, which created a framework to place the emphasis on a One Health approach. For instance, four WGs are common to the three national surveillance platforms. This article aims to present this innovative approach to improve surveillance efficiency that could be of interest to other European countries or that could be rolled out at the European level. [ABSTRACT FROM AUTHOR]

Objective: This study validates a direct multiplex real-time reverse transcription polymerase chain reaction (rRT-PCR) assay which was previously established for enabling rapid and simultaneous detection of African swine fever (ASF) virus (ASFV) and classical swine fever virus. The assay eliminates the need for viral nucleic acid purification using a buffer system for crude extraction and an impurity-tolerant enzyme. However, the assay had not yet been validated using field samples of ASFV-infected pigs. Therefore, to address this gap, we tested 101 samples collected from pigs in Vietnam during 2018 and 2021 for validation. Results: The rRT-PCR assay demonstrated a diagnostic sensitivity of 98.8% and a specificity of 100%. Remarkably, crude samples yielded results comparable to those of purified samples, indicating the feasibility of using crude samples without compromising accuracy in ASFV detection. Our findings emphasize the effectiveness of the rRT-PCR assay for the prompt and accurate diagnosis of both swine fever viruses, which is essential for effective disease prevention and control in swine populations. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) is one of the deadliest swine diseases, causing significant economic losses, threatening food security, and limiting pig production in affected countries. In the absence of an effective ASF vaccine, prevention and control of ASF depend mainly on effective biosecurity measures. In this study, the efficacy of SAFER®, a powdered disinfectant containing clay, an acid complex, and the active ingredient thyme essential oil, was tested against the ASF virus. The results showed that ASFV isolate (VNUA/HY/ASF1/Vietnam/2019) was inactivated by 3.5 and 5 Log10HAD50/ml after 20 and 120  min of treatment with SAFER®, respectively. When body fluids contaminated with ASFV, such as blood, saliva, urine, and feces, were treated with SAFER® for 20  min, the ASFV titer was reduced by 1.6, 2.2, 2.0, and 2.2 Log10HAD50/ml, respectively. [ABSTRACT FROM AUTHOR]

African Swine Fever (ASF) is a devastating viral hemorrhagic disease that causes high morbidity and mortality in domestic pigs and wild boars, severely impacting the swine industry. The etiologic agent, African Swine Fever virus (ASFV), mainly infects myeloid cells of the swine mononuclear phagocytic system (MPS). For other porcine viruses, in vitro culture models with primary cells are widely used as they mimic the in vivo viral replication behavior better compared to continuous cell lines. Our study validates this possible correlation for ASFV using cell culture models established for three different porcine macrophages, isolated from the lungs (porcine alveolar macrophages), blood (monocyte-derived macrophages) and spleen (spleen macrophages). The cells were infected with two genotype I and two genotype II strains with different pathogenic potential in vivo. The highly virulent strains replicated better in general than the low-virulent strains. This was most pronounced in monocyte-derived macrophages, although only statistically significant 18 h post-infection (hpi) in the intracellular genomic ASFV copies between E70 and the low-virulent strains. For this reason, we conclude that the different replication characteristics between the strains with different virulence do not proportionally represent the differences in pathology seen between the strains in vivo. Additionally, ASFV-positive cells were observed earlier in monocyte-derived macrophages (MDMs) compared to the alveolar and spleen macrophages, subsequently leading to an earlier rise in extracellular virus, and, ultimately, more MDMs were infected at the end of sampling. For these reasons, we propose MDMs as the best-suited cell type to study ASFV. [ABSTRACT FROM AUTHOR]

African swine fever virus (ASFV) is the causative agent of an often lethal disease in domestic pigs, African swine fever (ASF). ASF is currently a pandemic disease challenging pig production in Eurasia. While the ASFV genome encodes for over 160 proteins, the function of most of them are still not characterized. Among those ASF genes with unknown functions is the E111R gene. It has been recently reported that the deletion of the E111R gene from the genome of the virulent Chinese field isolate SY18 strain produced a reduction of virus virulence when pigs were inoculated at relatively low doses. Conversely, we report here that deletion of the ASFV gene E111R in the Georgia 2010 isolate does not alter the virulence of the parental virus in experimentally inoculated pigs. A recombinant virus lacking the E111R gene, ASFV-G-∆E111R was intramuscularly (IM) inoculated in domestic pigs at a dose of 102 HAD50 of ASFV-G-∆E111R and compared with animals that received a similar dose of virulent ASFV-G. Both, animals inoculated with either the recombinant ASFV-G-∆E111R or the parental virus developed a fatal form of the disease and were euthanized around the 6th–7th day post-inoculation (dpi). [ABSTRACT FROM AUTHOR]

African swine fever virus (ASFV) is endemic to African wild pigs (Phacochoerus and Potamochoerus), in which viral infection is asymptomatic, and Ornithodoros soft ticks. However, ASFV causes a lethal disease in Eurasian domestic pigs (Sus scrofa). While Sub-Saharan Africa is believed to be the original home of ASFV, publicly available whole-genome ASFV sequences show a strong bias towards p72 Genotypes I and II, which are responsible for domestic pig pandemics outside Africa. To reduce this bias, we hereby describe nine novel East African complete genomes in p72 Genotype IX and present the phylogenetic analysis of all 16 available Genotype IX genomes compared with other ASFV p72 clades. We also document genome-level differences between one specific novel Genotype IX genome sequence (KE/2013/Busia.3) and a wild boar cell-passaged derivative. The Genotype IX genomes clustered with the five available Genotype X genomes. By contrast, Genotype IX and X genomes were strongly phylogenetically differentiated from all other ASFV genomes. The p72 gene region, on which the p72-based virus detection primers are derived, contains consistent SNPs in Genotype IX, potentially resulting in reduced sensitivity of detection. In addition to the abovementioned cell-adapted variant, eight novel ASFV Genotype IX genomes were determined: five from viruses passaged once in primary porcine peripheral blood monocytes and three generated from DNA isolated directly from field-sampled kidney tissues. Based on this methodological simplification, genome sequencing of ASFV field isolates should become increasingly routine and result in a rapid expansion of knowledge pertaining to the diversity of African ASFV at the whole-genome level. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) is an acute infectious disease with a high mortality rate in both domestic and wild boars. Commercial vaccines or antiviral drugs for ASF were not available due to the complex diversity of the structure and genome of its pathogen African swine fever virus (ASFV). In recent years, there have been many reports on candidate strains of attenuated vaccines for ASFV. In this study, we obtained a recombinant virus named SY18ΔL60LΔCD2v by simultaneously deleting the L60L gene and CD2v gene from highly virulent strain SY18. In vitro, SY18ΔL60LΔCD2v displayed a decreased growth kinetic compared to that of parental SY18. In vivo, high doses (105 TCID50) of SY18ΔL60LΔCD2v can protect pigs (5/5) from attacks by the parental SY18 strain (102 TCID50). Low doses (102 TCID50) of SY18ΔL60LΔCD2v only protected 20% of pigs (1/5) from attacks by the parental SY18 strain (102 TCID50). The results indicated that the absence of these two genes in SY18 could induce protection against the homologous parental strain, and there were no obvious clinical symptoms or viremia. These results indicate that the SY18ΔL60LΔCD2v strain can serve as a new live attenuated vaccine candidate for the prevention and control of ASFV infection. [ABSTRACT FROM AUTHOR]

Simple Summary: African swine fever is a deadly disease affecting pigs worldwide, causing major economic losses. The virus strain causing the current outbreak in Europe and Asia, known as genotype II, was first identified in Georgia in 2007. This study aimed to analyze the genetic makeup of a strain found in Thailand to better understand its characteristics and how it compares to other strains in Asia. The viral DNA from an infected pig was analyzed and was found to be almost identical to strains from Georgia and China. The Thai strain had eight unique genetic changes, including small mutations in specific genes and deletions in others. This detailed genetic analysis helps track the spread and evolution of the virus, providing important information for developing strategies to control future outbreaks. By understanding these genetic differences, improved measures to protect pig populations can be implemented, thereby reducing the economic impact on the agricultural industry. African swine fever virus (ASFV) has been responsible for the globally devastating epidemics in wild and domesticated pigs. Of the 24 identified ASFV genotypes, genotype II is the primary cause for the pandemic occurring in Europe and Asia since its emergence in Georgia in 2007. The current study aimed to characterize the full-length genomic pattern of the ASFV strain from Thailand, TH1_22/CR (Accession No. PP915735), which was then compared with genomic diversity across other Asian isolates using Georgia 2007/1 (Accession No. FR682468) as the reference. Viral DNA was isolated from the pig spleen sample following library preparation and paired-end sequencing using the MiSeq Illumina platform. The sequenced TH1_22/CR isolate spanned 189,395 nucleotides encoding 193 open reading frames (ORFs), exhibiting maximum nucleotide similarity (99.99%) with Georgian (Georgia 2007/1) and Chinese (Wuhan 2019-1 and China HLJ) isolates. Based on phylogenetic analysis, the TH1_22/CR isolate (Accession No. PP915735) was characterized as genotype II, serogroup 8, and IGR-II due to the presence of three tandem repeat sequences (TRSs). Genetic variations including SNPs and single and polynucleotide indels were identified in TH1_22/CR in agreement with other Asian isolates. For comprehensive analysis, the genome was divided into four regions (I–IV) based on gene location. Overall, the TH1_22/CR isolate demonstrated eight SNPs and indels in its genome. Two unique SNPs were reported in the coding regions of the TH1_22/CR isolate, out of which, a C-591-T substitution was seen in MGF 360-4L and a C-297-T was found in A238L, and four unique SNPs were reported in non-coding regions (NCRs). Furthermore, a 29 bp deletion was observed in the IGR between MGF 110-13La and MGF 110-13Lb, as well as 52 bp deletion in the ASFV G ACD 00350 gene. This comparative analysis establishes the foundational information for future studies on the diversity and phylogeography of this regionally significant genetic sub-group of ASFV. [ABSTRACT FROM AUTHOR]

Simple Summary: The rapidly growing wild boar population has resulted in an increasing rate of human–wildlife conflicts, including economic damage to crops or spreading African swine fever (ASF), which affects the pork industry. This situation necessitates the adoption of various measures to prevent wild boar movement, mitigate spreading of diseases, and protect crops. We evaluated the impact of commonly used odor fences (Wildschwein Stopp) using GPS telemetry of tagged individuals. The telemetry of free-ranging wild boars demonstrated no effect on their crossing of the odor fence lines compared to before the installation. Moreover, no difference was found when comparing the home range size of monitored individuals during the 22 days before and after odor fence installation. Therefore, our findings do not support using odor fences to prevent wild boar movement as a mitigation measure of ASF transmission or line protection against the damage caused by wild boars to crops. Wild boars are an opportunistic wildlife species that has successfully colonized the human-modified landscape in Europe. However, the current population boom has negative consequences, which result in a rapid increase in human–wildlife conflicts and disease transmission, including African swine fever (ASF). The increasing frequency of conflicts requires adequate solutions for these issues through various measures. Application of deterrents is a common non-lethal measure whose effects have been insufficiently verified until recently. Thus, this study aims to evaluate the effectiveness of odor fences, often applied as a barrier against wild boar movement. For this purpose, 18 wild boars were marked with GPS collars. After 22 days of initial monitoring, 12 sections of odor fences were installed on their home ranges. The monitored wild boars crossed the area 20.5 ± 9.2 times during the pre-installation period and 19.9 ± 8.4 times after the odor fence installation. Moreover, the average home range varied between 377.9 ± 185.0 ha before and 378.1 ± 142.2 ha after the odor fence installation. Based on GPS telemetry results, we do not support using odor repellent lines for crop protection or for limiting wild boar movement to lessen ASF outbreaks. [ABSTRACT FROM AUTHOR]

Simple Summary: The Danish pig industry, in collaboration with the authorities, has implemented several risk-reducing measures to prevent the introduction of African Swine Fever into Danish pig production. Ongoing risk assessments are conducted to adjust or establish new measures. The first outbreaks in a new area in Northern Europe often occur in wild boar, likely due to discarded food waste at rest areas and in forested areas. A fence has been established on the Danish–German border to limit the migration of wild boar from Germany to Denmark, and the limited population of wild boar in Denmark has been culled. All trucks that transport pigs or cattle are cleaned and disinfected at the border if they have been abroad, according to the DANISH Transportstandard. Through continuous contact with the feed industry, changes in the importation of feedstuffs and other auxiliaries are analyzed, and risk assessments for each feed item are conducted. Based on this, according to the Danish Product Standard, it is not permitted to store or use feed items such as hay, straw, silage, or bedding imported from areas with outbreaks of African Swine Fever on Danish properties with pigs. These types of feed items can contain parts of dead animals in which the virus can survive for a long time. Oil cakes, fats, and oils imported from countries with African Swine Fever may only be used after heat treatment. African Swine Fever poses a significant threat to pig production. An outbreak in Denmark would have severe economic consequences, potentially resulting in a loss between 335 million and 670 million euros. To mitigate the major risk factors, the Danish authorities and the Danish pig industry have implemented several risk-reducing measures. The small wild boar population in Danish nature has been culled, and a fence between Denmark and Germany has been constructed to stop or reduce the risk of migrating wild boar from Germany. All trucks arriving from abroad, intended for the transport of Danish pigs, are inspected, washed, and disinfected at facilities near the border before being allowed to transport pigs between herds or from herds out of Denmark. Cross-border trade of feedstuffs and potentially risky materials is continuously monitored. Based on risk assessments, feed types or bedding materials from countries with African Swine Fever that could contain parts of wild boar are banned from Danish pig herds. Certain types of fats and oils from countries with African Swine Fever can only be used after heat treatment. The import of whole kernels of corn, wheat, or barley is not considered a risk. [ABSTRACT FROM AUTHOR]

Simple Summary: African swine fever (ASF) presents a significant challenge in Asia, where outbreaks have devastated the pork industry and threatened food security due to high mortality rates in pigs. The disease, caused by the ASF virus genotype II, has spread rapidly across the region since its emergence in China in 2018. This paper discusses the introduction and implications of vaccines such as NAVET-ASFVAC and AVAC ASF Live in Vietnam, emphasizing the necessity for rigorous testing and regulatory oversight. Despite the potential use of vaccines to control the disease, concerns about the safety of live attenuated vaccines (LAVs), including their ability to revert to virulence or create new recombinant strains, highlight the complexity of ASF management. Effective vaccine strategies, alongside strict biosecurity measures, and rapid diagnostics are essential to mitigate the economic and social impacts of ASF and ensure the stability of pig populations in Asia. This paper explores the significance of quality vaccines in managing ASF in Asia, where it poses a substantial threat to the pork industry. It emphasizes the risks associated with substandard vaccines, including the emergence of new virus strains that complicate disease control. Highlighting recent advancements in vaccine deployment in Vietnam, the paper calls for rigorous testing and regulations to guarantee vaccine effectiveness and safety. The authors advocate for the implementation of vaccines with the inclusion of differentiating infected from vaccinated animals (DIVA), which enhances disease management strategies in both endemic and non-endemic regions. The conclusion underscores the necessity of stringent standards in vaccine development and strict adherence to regulatory guidelines to ensure successful ASF management and maintain public trust in the vaccines. [ABSTRACT FROM AUTHOR]

Simple Summary: African swine fever (ASF) causes serious economic losses to the global pig industry. Although several commercial vaccines have been registered in some Asian countries, the development of ASF vaccines is still actively continuing. One of the current trends is the development of a safe DIVA vaccine against ASF, the use of which will allow differentiating between infected or vaccinated pigs. To date, commercial ASF vaccines are live vaccines based on the ASFV attenuated strains with the deletion of the viral genes responsible for virulence. However, some recombinant strains with the deletions of virulence genes may have residual virulence and be unsafe. In our work, we have shown that the infection of animals with the ASFV A137R-deletion mutant with a dose 10 times higher than the described safe dose leads to the death of 87.5% of the infected animals. We assume that the deletion of the A137R gene may be additionally introduced into the genomes of candidate vaccine strains in order to reduce their reactogenicity and as an antigenic and genetic marker for the differentiation of infected and vaccinated animals (DIVA strategy). African swine fever (ASF) is an emerging disease caused by the African swine fever virus (ASFV), which is a great threat to the swine industry worldwide. Currently registered vaccines that have demonstrated protection against the homologous ASFV strains are live attenuated vaccines based on recombinant ASFV strains with the deletions of virulence-associated genes. In this study, we evaluated the deletion of the A137R gene in the ASFV virulent Stavropol_01/08 strain isolated in Russia in 2008. Our animal experiment results demonstrated that the deletion of the A137R gene did not lead to the full attenuation of this strain, and increasing the dose of the A137R-deletion mutant during infection led to the death of 87.5% of the infected animals. In this report, we also demonstrated that immunofluorescence (IFA) and Western blotting assays based on the recombinant p11.5 protein can be used to detect antibodies in animals infected with the attenuated ASFV variants of several genotypes/serotypes. Both assays were specific to ASFV p11.5 protein and showed negative results when examining the sera of the non-infected animals or those infected with the A137R-deletion mutant. Therefore, we propose to use the p11.5 protein along with other previously proposed ASFV proteins, such as CD2v, as negative antigenic DIVA markers for an attenuated ASF vaccine. [ABSTRACT FROM AUTHOR]

In early 2022, the confirmed presence of African swine fever (ASF) circulating in wild boars in mainland Italy and subsequently found in domestic pigs led to several changes regarding the export of pork and pork products to countries outside the European Union (non-EU). The sector suffered the complete and immediate closure of the markets of some countries, often without the measure being communicated in the forms stipulated by international agreements. Indeed, compliance with the current EU regulations does not guarantee the possibility of exporting to non-EU countries. Knowledge of the animal health status requirements of the country (Italy in this case) is essential for food business operators (FBOs) wishing to enter markets outside the EU according to the 'Agreement on the Application of Sanitary and Phytosanitary Measures'. In cases where a sanitary protocol and a model of an official certificate with the importing country exist, the market is officially accessible according to the agreed sanitary requirements. Where no agreement exists, requirements are detailed in the 'import permit' issued to individual FBOs or may be known by directly accessing national regulations through the client/importer. Therefore, the purpose of this work is to briefly outline the conditions imposed by the main non-EU countries for pork products, especially in light of the new epidemiological situation created by the spread of the ASF into a country previously free of the disease. [ABSTRACT FROM AUTHOR]

Owing to the lack of effective vaccines, current control measures and eradication strategies for the African swine fever virus (ASFV) rely on early detection and stringent stamping-out procedures. In the present study, we developed two independent isothermal amplification assays, namely, loop-mediated isothermal amplification (LAMP) and polymerase spiral reaction (PSR), for quick visualization of the ASFV genome in clinical samples. Additionally, a quantitative real-time PCR (qRT-PCR)-based hydrolysis probe assay was developed for comparative assessment of sensitivity with the developed isothermal assays. The analytical sensitivity of the LAMP, PSR, and qRT-PCR was found to be 2.64 ×105 copies/µL, 2.64 ×102 copies/µL, and 2.64 ×101 copies/µL, respectively. A total of 165 clinical samples was tested using the developed visual assays. The relative accuracy, relative specificity, and relative diagnostic sensitivity for LAMP vs PSR were found to be 95.37% vs 102.48%, 97.46% vs 101.36%, and 73.33% vs 113.33%, respectively. [ABSTRACT FROM AUTHOR]

Simple Summary: The spread of the African swine fever virus (ASFV) poses a great threat to the global pig industry and new measures for prevention and control are urgently needed. With no effective vaccines, drug development against ASFV is crucial. This study screened 536 antiviral compounds and identified that punicalagin, from pomegranate peel, significantly inhibited ASFV replication in various cell lines in vitro. Punicalagin acted on early viral replication stages, including attachment and internalization, and directly inactivated the virus. Finally, it was found that punicalagin could modulate the NF-κB/STAT3/NLRP3 signaling pathway, reducing ASFV-induced inflammation. These results provide an experimental basis for the use of punicalagin in developing anti-ASFV candidate drugs. African swine fever (ASF), caused by the African swine fever virus (ASFV), has resulted in significant losses in the global pig industry. Considering the absence of effective vaccines, developing drugs against ASFV may be a crucial strategy for its prevention and control in the future. In this study, punicalagin, a polyphenolic substance extracted from pomegranate peel, was found to significantly inhibit ASFV replication in MA-104, PK-15, WSL, and 3D4/21 cells by screening an antiviral compound library containing 536 compounds. Time-of-addition studies demonstrated that punicalagin acted on early viral replication stages, impinging on viral attachment and internalization. Meanwhile, punicalagin could directly inactivate the virus according to virucidal assay. RT-qPCR and Western blot results indicated that punicalagin modulated the NF-κB/STAT3/NLRP3 inflammasome signaling pathway and reduced the levels of inflammatory mediators induced by ASFV. In conclusion, this study reveals the anti-ASFV activity of punicalagin and the mechanism of action, which may have great potential for developing effective drugs against ASFV. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, pigs were inoculated with the ASFV strain HB31A via intramuscular and oronasal routes to investigate the viral dynamics and pathogenicity of ASFV. Pigs in the intramuscular group exhibited more reproducible clinical disease with a high consistency in disease outcomes. In contrast, pigs in the oronasal group had a longer incubation period, a prolonged course of disease, and a delayed onset of viral shedding. Additionally, one pig in the oronasal group that survived the infection exhibited chronic disease and persistent infection, intermittently excreting the virus and developing low-level viremia. This phenomenon indicates that pigs infected with ASFV in the field can develop non-lethal chronic disease and persistent infection, with intermittent viral excretion, even when infected with a highly virulent strain. These findings suggest that the survival of ASFV-infected pigs in the field poses a significant threat to uninfected pigs and can lead to severe economic losses in the pig industry. African swine fever is an extremely infectious viral disease that can cause nearly 100% mortality in domestic pigs. In this study, we isolated an ASFV strain HB31A and characterized it using hemadsorption assay, immunofluorescence assay, and electron microscopy. We then performed animal experiments on 20-day-old pigs through intramuscular and oronasal inoculations with HB31A. Pigs in the intramuscular group exhibited more consistent clinical disease, with an incubation period of 4.33 ± 0.47 days and a 100% mortality rate within 6.67 (±0.47) days post-inoculation (dpi). In contrast, the oronasal group experienced a longer course of disease, with an incubation period of 6.00 ± 0.82 days. Two out of three pigs in the oronasal group died at 8 and 10 dpi, while the surviving pig exhibited chronic disease and persistent infection, intermittently excreting ASFV through the oral, nasal, and rectal pathways. Virus DNA was found in oral, nasal, and rectal swabs at 1–3 dpi in the intramuscular group and at 3–5 dpi in the oronasal group. In summary, HB31A is highly lethal to domestic pigs, and field-infected pigs have the potential to develop non-lethal, chronic disease and persistent infection, with intermittent viral shedding, even when infected with a highly virulent strain. These findings offer a valuable understanding of the viral dynamics and pathogenicity of ASFV and highlight the difficulties in diagnosing, preventing, and controlling African swine fever. [ABSTRACT FROM AUTHOR]

African Swine Fever (ASF) is a severe viral disease that has significantly impacted the pig farming industry in China. It first broke out in China in 2018 and quickly spread to multiple provinces, significantly affecting the production efficiency of the pig farming industry. This study utilized pig production data from 17 provinces in China from 2010 to 2022 and applied the Malmquist production efficiency index and panel regression methods to assess the impact of the ASF epidemic on the efficiency of the pig farming industry. The results indicated that the outbreak of ASF significantly reduced overall production efficiency, which magnified the vulnerabilities of the production system. Although there was a general decline in technological change and pure technical efficiency, the increase in scale efficiency suggested effective resource optimization by farmers under resource-constrained conditions. In light of these findings, it is recommended to strengthen biosecurity education and epidemic prevention measures in the pig farming industry and to enhance technological innovation and the application of smart technologies to improve production efficiency and disease response capabilities. Additionally, timely adjustments in farming scale and resource optimization will be key to addressing future challenges. Through these strategies, the pig farming industry can maintain stable production efficiency during future epidemics and push towards a more efficient and refined production model. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) first broke out in China in August 2018 and triggered a substantial shock to the Chinese hog industry. Based on daily data from August 3, 2018, to May 30, 2020, we construct ASF news textual sentiment as a measurement indicator for the ASF epidemic and use a quantile regression model to examine the impacts of ASF news textual sentiment on the stock returns of hog firms. To assess the sentiment effect across periods, we divide the whole sample into three periods according to the trend in hog prices. Our results indicate that ASF news textual sentiment has a significant positive effect on stock returns across the period, but the effect varies across the three periods. In the stationary period, the sentiment has a significant positive effect on stock returns; the effect is reversed in rising and fluctuating periods. In addition, the sentiment effect varies across quantiles. The sentiment has asymmetric effects on stock returns, with a greater impact on higher returns. Our results suggest that opportunities to expand in scale and upgrade biological prevention and control on Chinese hog firms have long-term positive impacts on the development of the hog industry by ASF. [ABSTRACT FROM AUTHOR]

Abstract Objective This study validates a direct multiplex real-time reverse transcription polymerase chain reaction (rRT-PCR) assay which was previously established for enabling rapid and simultaneous detection of African swine fever (ASF) virus (ASFV) and classical swine fever virus. The assay eliminates the need for viral nucleic acid purification using a buffer system for crude extraction and an impurity-tolerant enzyme. However, the assay had not yet been validated using field samples of ASFV-infected pigs. Therefore, to address this gap, we tested 101 samples collected from pigs in Vietnam during 2018 and 2021 for validation. Results The rRT-PCR assay demonstrated a diagnostic sensitivity of 98.8% and a specificity of 100%. Remarkably, crude samples yielded results comparable to those of purified samples, indicating the feasibility of using crude samples without compromising accuracy in ASFV detection. Our findings emphasize the effectiveness of the rRT-PCR assay for the prompt and accurate diagnosis of both swine fever viruses, which is essential for effective disease prevention and control in swine populations.

As part of extensive molecular and genetic research into African swine fever virus isolates circulating in Russia, a recombinant variant with a mosaic genome structure has been identified. The one that caused an outbreak on a pig farm in the Primorsky Krai, in 2023. The characterized strain ASFV/Primorsky_2023/DP-4560.Recdemonstrates hemadsorption, active propagation in porcine primary macrophage cell culture, 99.9917% identity with the first recombinant isolates from the People’s Republic of China, recovered in 2021. Recombination sites included 79 open reading frames homologous to genotype II isolates; 49 ones homologous to genotype I and 12 mixed ones. Testing biomaterial from dead pigs in real-time polymerase chain reaction showed no changes in sensitivity or specificity, despite significant genetic distinctions between the recombinant and genotype II isolates that are enzootic to the Russian Federation. However, in 2023, D. Zhao et al. reported on high virulence of the virus related variants as revealed by the challenge tests in domestic pigs. Given the accelerating rates of AFSV molecular evolution in the East Asian countries (China, Vietnam and the Far Eastern regions of Russia), it is required to improve control measures, general and specific prevention, national and international surveillance over the economically significant animal disease.

African swine fever is a viral disease that causes hemorrhagic fever in domestic pigs and wild swine worldwide. The first case of ASF in Indonesia was reported in North Sumatra Province in September 2019. A total of 20 archival samples of positive ASF collected from the Animal Disease Investigation Center of Medan during the outbreak investigation took place from 2019 to 2023, were used in this study. The partial B646L gene (p72), the full sequence of the E183L gene (p54) and the central variable region (CVR) of the B602L gene were amplified, purified, then sequenced. Web-based BLAST program and MEGA XI software were used to analyze the nucleotide sequencing results. The results of molecular and phylogenetic characterization analysis revealed that the ASF virus that infected pigs in North Sumatra Province in 2019-2023 was belonged to genotype II. Analysis of the three genes (B646L, E183L and B602L) did not show changes in the nucleotide and amino acid sequences in the isolates in the last 5 years. No novel variants were found in the CVR gene B602L. CVR analysis showed that these ASF virus strain belonged to subgroup XXXII. The results of this study revealed that the ASF virus in North Sumatra Province has high homology with ASF virus isolates previously detected in China, Vietnam and East Leste in 2019.

Abstract The 2018 African swine fever (ASF) outbreak highlighted the importance of biosecurity in food production systems. Despite the significant economic impacts, the sociopsychological consequences on decision-making have been overlooked. Previous studies have focused on algebraic models and simulation-based models without considering the complex psychological and social factors that influence farmers' biosecurity behaviors and decision-making processes. This study aims to classify livestock producers into distinct subgroups based on their attitudes towards biosecurity. We conducted a survey presenting producers with three scenarios to assess their willingness to report suspected ASF cases, trust in government agencies, risk perception, biosecurity knowledge, willingness to purchase livestock insurance, motivation to invest in biosecurity, readiness to report suspected infections, and intention to contact a veterinarian. Using latent class analysis, we identified three distinct classes: Biosecurity Sceptics, Biosecurity Compliant, and Biosecurity Ultra-Compliant. Our results show that producer characteristics significantly influence biosecurity attitudes and class membership, with small-scale producers less likely to adopt ultra-compliant biosecurity practices. Attending at least one eradication program encouraged biosecurity compliance. This research informs the design of targeted food policy and risk communication strategies that account for attitudes of livestock producers to encourage biosecurity adoption and reduce the likelihood of Tier 1 disease incursion.

Abstract Background Soft ticks of the genus Ornithodoros are responsible for the maintenance and transmission of the African swine fever (ASF) virus in the sylvatic and domestic viral cycles in Southern Africa. They are also the main vectors of the Borrelia species causing relapsing fevers. Currently, no genetic markers are available for Afrotropical Ornithodoros ticks. As ASF spreads globally, such markers are needed to assess the role of ticks in the emergence of new outbreaks. The aim of this study is to design microsatellite markers that could be used for ticks of the Ornithodoros moubata complex, particularly Ornithodoros phacochoerus, to assess population structure and tick movements in ASF endemic areas. Methods A total of 151 markers were designed using the O. moubata and O. porcinus genomes after elimination of repeated sequences in the genomes. All designed markers were tested on O. phacochoerus and O. porcinus DNA to select the best markers. Results A total of 24 microsatellite markers were genotyped on two populations of O. phacochoerus and on individuals from four other Ornithodoros species. Nineteen markers were selected to be as robust as possible for population genetic studies on O. phacochoerus. Conclusions The microsatellite markers developed here represent the first genetic tool to study nidicolous populations of O. phacochoerus. Graphical Abstract