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The African swine fever virus (ASFV) causes African swine fever (ASF), a highly lethal disease affecting domestic pigs and wild boars. Since its initial outbreak in October 2019 in Yeoncheon, Gyeonggi Province, ASF has continued to spread in South Korea. This study aimed to differentiate closely related ASFV strains through the analysis of the intergenic region (IGR) between I73R and I329L genes. In 2019, genetic analysis confirmed one IGR I type case and two IGR III type cases in Paju, followed by two more IGR III type cases in 2020. After a period of detecting only the IGR II type, IGR III type cases re‐emerged in Pohang and Cheong‐song in November and December 2023. Genetic analysis using B646L, CP204, B602L, and EP402R genes confirmed that the IGR III strains belong to genotype II and serogroup 8, similar to the Georgia/2007/1 strain but differing in IGR type. Since the first occurrence of ASF in wild boars in South Korea, we have continuously monitored the introduction and variation of ASFV. As a result, we reconfirmed the presence of the IGR III type ASFV in 2023, 3 years and 8 months later, in a different area from where it was last detected. This finding would not have been possible without the continuous monitoring of ASFV introduction and genetic variation. We emphasize the critical role of regular monitoring based on molecular markers and comprehensive genomic analysis in enhancing the effectiveness of ASFV control and prevention. [ABSTRACT FROM AUTHOR]

Porcine reproductive and respiratory syndrome virus (PRRSV), known for causing reproductive disorders in sows and respiratory issues in piglets, poses a significant threat to the global swine industry. Since its initial report in 2013, the L1C (lineage 1.8/NADC30‐like) PRRSV has drawn significant attention in China due to its high recombination potential and diverse pathogenicity. This study focuses on a naturally occurring recombinant L1C variant, SCABTC‐202302, characterized by an restriction fragment length polymorphism (RFLP) pattern of 1‐4‐3. We investigate the strain's genetic evolution, recombination, pathogenicity, and immune and antibody responses. Phylogenetic analysis of the ORF5 (open reading frame) gene classified the SCABTC‐202302 strain as lineage 8.7, while whole‐genome analysis categorized it as L1C. Notably, a discontinuous deletion of 131 amino acids (AAs) was observed in the NSP2 gene, along with specific AA mutations in ORF5. Recombination analysis revealed the NADC30 strain as the primary parent, with contributions from the JXA1 strain in the ORF2‐ORF7 region. The strain caused lung and lymph node damage, sustained high‐level viremia, and elevated inflammatory factors in infected piglets. Our study provides valuable insights into the genetic characteristics, pathogenicity, and immunological profile of L1C strains, contributing to the development of vaccines and control measures for PRRSV. [ABSTRACT FROM AUTHOR]

Background: Although the rate of emerging infectious diseases that originate in wildlife has been increasing globally in recent decades, there is currently a lack of epidemiological data from wild animals. Methodology: We used serology to determine prior exposure to foot‐and‐mouth disease virus (FMDV), Brucella spp., and Coxiella burnetii and used genetic testing to detect blood‐borne parasitic infections in the genera Ehrlichia, Anaplasma, Theileria, and Babesia from wildlife in two national parks, Kruger National Park (KNP), South Africa, and Etosha National Park (ENP), Namibia. Serum and whole blood samples were obtained from free‐roaming plains zebra (Equus quagga), greater kudu (Tragelaphus strepsiceros), impala (Aepyceros melampus), and blue wildebeest (Connochaetes taurinus). Risk factors (host species, sex, and sampling park) for infection with each pathogen were assessed, as well as the prevalence and distribution of co‐occurring infections. Results: In KNP 13/29 (45%; confidence interval [CI]: 26%–64%) kudus tested positive for FMD, but none of these reacted to SAT serotypes. For brucellosis, seropositive results were obtained for 3/29 (10%; CI: 2%–27%) kudu samples. Antibodies against C. burnetii were detected in 6/29 (21%; CI: 8%–40%) kudus, 14/21 (67%; CI: 43%–85%) impalas, and 18/39 (46%; CI: 30%–63%) zebras. A total of 28/28 kudus tested positive for Theileria spp. (100%; CI: 88%–100%) and 27/28 for Anaplasma/Ehrlichia spp. (96%; CI: 82%–100%), whereas 12/19 impalas (63%) and 2/39 zebra (5%) tested positive for Anaplasma centrale. In ENP, only 1/29 (3%; CI: 0%–18%) wildebeest samples tested positive for FMD. None of the samples tested positive for brucellosis, while C. burnetii antibodies were detected in 26/30 wildebeests (87%; CI: 69%–96%), 16/40 kudus (40%; CI: 25%–57%), and 26/26 plains zebras (100%; CI: 87%–100%). A total of 60% Anaplasma/Ehrlichia spp. and 35% Theileria/Babesia spp. in kudu and 37% wildebeest tested positive to Theileria sp. (sable), 30% to Babesia occultans, and 3%–7% to Anaplasma spp. The seroprevalence of Q fever was significantly higher in ENP, while Brucella spp., Anaplasma, Ehrlichia, Theileria, and Babesia species were significantly higher in KNP. Significant coinfections were also identified. Conclusion: This work provided baseline serological and molecular data on 40+ pathogens in four wildlife species from two national parks in southern Africa. [ABSTRACT FROM AUTHOR]

Hedgehog (Erinaceus europaeus) declines in western Europe have been associated with the emergence of Hedgehog diphtheric disease (HDD), with a probable multifactorial, yet unidentified etiology. We used metagenomic sequencing of cell‐free DNA (cfDNA) in hedgehog blood to identify possible causes of HDD. We detected a novel circovirus species in the European hedgehog, providing the first record of a circovirus within the mammalian order Eulipotyphla. The novel circovirus genome exhibits the characteristic circovirus structure, including a functional replicase (REP) and capsid (CAP) gene. Phylogenetic analysis placed all four detected genomes in a monophyletic clade, most closely related to sequences isolated from dogs. Subsequent PCR‐based screening of 188 hedgehog liver samples demonstrated a high prevalence (61%) of this circovirus in hedgehogs brought to wildlife rescue centers, however, without any significant association with HDD. Since circoviruses are well known to interfere with host immunity across mammalian and avian taxa, the high level of circovirus detection in hedgehogs warrants further research into the role of this novel virus in hedgehog health. [ABSTRACT FROM AUTHOR]

Rabbit hemorrhagic disease is a highly contagious and acute fatal disease caused by rabbit hemorrhagic disease virus (RHDV). The first outbreak of RHDV2 in 2020 has posed a serious threat to the rabbit breeding industry in China. An effective and specific detection strategy for RHDV GI.1 (RHDV1) and GI.2 (RHDV2) is urgently needed. In this study, we established a reverse transcription loop‐mediated isothermal amplification (RT‐LAMP)‐CRISPR/Cas12a‐based dual readout portable detection platform. The platform showed excellent specificity to identify RHDV1 and RHDV2 strains and no cross‐reaction with other prevalent pathogens of rabbit. The detection limit for RHDV1 and RHDV2 by RT‐LAMP‐CRISPR/Cas12a could reach 10 copies/μl of the VP60 gene per reaction. Furthermore, 74 clinical samples were detected for both RHDV1 and RHDV2. RT‐LAMP‐CRISPR/Cas12a‐based dual readout portable detection platform showed 25.68% (19/74) RHDV1‐positive samples, 43.24% (32/74) RHDV2‐positive samples, and 8.11% (6/74) RHDV1/RHDV2 double positive samples, respectively. The coincidence rates of detection RHDV1 and RHDV2 between RT‐LAMP‐CRISPR/Cas12a and quantitative real‐time‐polymerase chain reaction (qPCR) were both 97.30%. RT‐LAMP‐CRISPR/Cas12a showed higher sensitivity and detection rate compared with qPCR. Moreover, the results were visible to the naked eye within 1.5 h combined with lateral flow strips (LFSs) and visual fluorescence. The RT‐LAMP‐CRISPR/Cas12a portable platform has the advantages of high sensitivity, specificity, fast, low equipment requirements, which can be used in clinical practice in rural areas and resource‐limited settings. [ABSTRACT FROM AUTHOR]

To date, seven novel parvoviruses have been identified in pigs and designated as porcine parvovirus 2–7 (PPV2–7). The presence of these emerging viruses has been reported in several countries around the world, although their pathogenic role and clinical and economical relevance are largely unknown. Here, we report the estimated prevalence and genetic diversity of novel PPV2–7 in Hungarian pig herds and the detection of these viruses in two Slovakian pig farms. For the comparative prevalence estimation, 2505 serum samples from different age groups, 218 oral fluid samples, and 111 processing fluid samples were collected from 26 large‐scale Hungarian farms according to a systematic, cross‐sectional sampling protocol. All samples were tested by real‐time quantitative polymerase chain reaction (qPCR), and the presence of at least one PPV was detected in 24 of the 26 (92%) Hungarian and both Slovakian farms, suggesting high levels of subclinical circulation in most herds. The estimated PPV2–7 prevalence in Hungary varied from 50% to 89%, with PPV4 being the least and PPV2 being the most prevalent virus. The highest detection rates were observed in oral fluid samples, indicating that this sample type is most suitable for screening PPVs, but all viruses were also detected in serum samples and processing fluids. All novel PPVs were most frequently detected in the serum samples of weaned pigs and fatteners, with slightly higher viral burden in the younger age groups. These results may suggest an age‐related susceptibility, which could play a significant role in the epidemiology of these viruses, impacting herd health and productivity. [ABSTRACT FROM AUTHOR]

A high pathogenicity avian influenza (HPAI) subtype H7N6 virus emerged in South African poultry in 2023 and later spread to Mozambique, the first documented emergence of H7 HPAI in the African continent. A total of 6.82 million birds succumbed to the disease or were culled, representing about 20% of the South African egg‐laying flock and almost 30% of the broiler breeder flock. The complete genomes of 68 outbreak viruses were sequenced and analyzed, tracing the phylogenetic origins of the ancestral H7N6 virus to a reassortment of various subtypes that circulated in southern African wild birds. Molecular clock analysis determined that the virus emerged in the first week of May 2023, probably in a smallholder chicken flock, before spreading to commercial farms, where the disease was first reported in early June. The multibasic hemagglutinin protein cleavage site (HA0) was derived from a nonhomologous recombination event with chicken 28S ribosomal ribonucleic acid (RNA). Few genetic markers associated with an increased risk to humans were present in the translated viral proteins. The intravenous pathogenicity index (IVPI) value of the index case isolate was 1.67, reflecting that 50% of the specific pathogen‐free chickens died within 4 days of infection. Surviving birds showing mostly mild clinical signs and recovered by day 10 postinfection. Prior to death, chickens shed the virus primarily through the respiratory route, with lower amounts shed from the cloaca, but in the survivors, the virus was still being shed from the cloaca on day 10. Fomites were the likely source of disease spread between farms, and the amount of H7N6 HPAI virus per gram of feces was calculated at ~383,193 (5.58 log10) egg infectious dose 50 (EID50) equivalents, chicken feather follicles contained on average 739,712.43 (5.87 log10) EID50 equivalents, and 20 µg of feather dust contained 14,976.96 (4.175 log10) EID50 equivalents. [ABSTRACT FROM AUTHOR]

Wild rodents and their ectoparasites are known reservoirs for various zoonotic pathogens, highlighting the need for detailed studies into their roles in disease transmission. Our research investigated the spatial distribution of rodents and their ectoparasites to better understand the epidemiology of vector‐borne zoonotic diseases (VBZDs), including severe fever with thrombocytopenia syndrome (SFTS), Lyme disease, Q fever, and scrub typhus. We analyzed samples from 540 rodents and 6785 mites, detecting the presence of Borrelia spp., the causative agent of Lyme disease, in 0.9% of rodents and SFTS virus (SFTSV) in 1.0%. In mites, Borrelia spp. and Orientia tsutsugamushi, the bacteria causing scrub typhus, were detected in 0.3% of samples each. Phylogenetic analysis identified the SFTSV sequence as type B3, the Borrelia spp. sequence as B. afzelii, and the O. tsutsugamushi sequence as Karp‐related. Notably, SFTSV was detected for the first time in mites in South Korea, and B. afzelii was found in mites for the first time globally. These findings emphasize the critical need for continuous analysis of VBZDs to anticipate future trends and develop a comprehensive monitoring system. Further research into the rodent and mite populations in South Korea is essential to fully assess the potential risks of VBZDs. [ABSTRACT FROM AUTHOR]

Porcine reproductive and respiratory syndrome virus (PRRSV) is a significant pathogen in the worldwide swine industry. The virus shows high genetic variation coupled with a broad range of virulence in pigs. Although multiple lineages of the virus have been prevalent throughout in Korea, the characteristics of lineage‐wise pathogenicity are largely unknown. Therefore, this study was designed to analyze and compare the pathogenicity of 11 representative Korean PRRSV‐2 isolates selected from PRRSV‐2 lineages circulating in Korea, NADC30‐like, VR2332‐like, and three nation‐specific lineages (lineage KOR A (LKA), lineage KOR B (LKB), and lineage KOR C (LKC)), which have been continuously prevalent in the nation. Eleven groups of pigs were experimentally infected with one Korean PRRSV‐2 isolate through four consecutive animal experiments. Body weight and body temperature were recorded during each 4‐week challenge experiment period, and virological, serological, and histopathological tests were performed on the collected samples. The data from the animal experiments were integrated into two indicators—excretion and clinical signs—through correlation and principal component analysis (PCA). Meta‐analysis was used to compare PRRSV‐2 isolates using each indicator. Based on these analyses, while L1C viruses used in this study (JB15‐N‐P31‐GB and JB15‐N‐PJ73‐GN, similar to NADC30‐like strains) exhibited low or moderate levels of excretion and clinical signs, lineage 5 (L5) or modified live vaccine (MLV)‐variant strains exhibited high levels of excretion compared to other PRRSV‐2 isolates. However, the L5 variants all caused mild clinical signs, except for JB15‐N‐PJ4‐GN, which showed the 4th highest clinical sign indicator. Among the Korean lineages (LKA, LKB, and LKC), two LKB strains (GGYC45 and JB15‐N‐PJ10‐GN) were the most virulent as they showed the highest mortality after the challenge. On the other hand, the LKA and LKC viruses displayed lower excretion indicators than L5 strains, but they had higher‐ranked clinical sign indicators than low‐virulence L5 MLV variants. In conclusion, PRRSV prevalent in Korea has diverse excretion and clinical characteristics, and certain lineage is highly pathogenic. These results will offer useful insights to prevent spread of PRRSV and improve the efficacy of vaccines in the future. [ABSTRACT FROM AUTHOR]

Porcine reproductive and respiratory syndrome virus (PRRSV), encompassing PRRSV‐1 and PRRSV‐2, significantly impacts the global pig industry by causing reproductive disorders and respiratory difficulties. In this paper, we isolated a novel PRRSV‐1 strain, named SCPJ2023, from weaned piglets in Sichuan. Utilizing primary macrophages, we isolated SCPJ2023 and performed complete genome sequencing through metagenomic analysis. Phylogenetic analysis classified SCPJ2023 as pan‐European subtype 1. SCPJ2023 showed a 95.3% similarity to SC2020‐1. Amino acid analysis identified differences in Nsp2, GP3, and GP4 between SCPJ2023 and other representative strains. In vivo challenge experiments demonstrated that SCPJ2023 induced clinical symptoms in piglets, including coughing, fever, reduced appetite, and depression. Pathological examinations revealed hemorrhage and congestion, increased inflammatory cells, thickening of the alveolar wall, and collapse of the alveolar cavity in SCPJ2023‐infected piglets. Altogether, our study identified a novel pathogenic isolate of PRRSV‐1, expanding the newly named SC2020‐1‐like subgroup by identifying additional strains beyond the initial SC2020‐1 isolate. [ABSTRACT FROM AUTHOR]

Eimeria stiedae is one of the few eukaryotic pathogens that exclusively infect the liver and serves as a good model to study the host–pathogen interactions in this vital organ. In this study, we show that rabbits infected with E. stiedae develop severe but self‐healing cholangitis. RNA‐seq analysis of the liver gene expression landscapes over the long course of E. stiedae infection identified 912 differentially expressed genes (DEGs) in the prepatent period (794 up‐ and 118 downregulated genes), 2889 DEGs in the early oocyst shedding period (1870 up‐ and 1019 downregulated genes), 2859 DEGs in the peak oocyst shedding period (1923 up‐ and 936 downregulated genes), and 327 DEGs in the recovery period (164 up‐ and 163 downregulated genes). Combined with pathological observations, we identified dynamic changes in host–parasite interactions involving multiple pathways. They showed that E. stiedae infection induced full‐blown inflammatory, Th1 and Th17 immune responses at all time points. This was associated with the strong innate immune responses during the prepatent period, including increased Toll‐like and NOD‐like receptor signaling. Despite mounting several damage control and repair responses, such as PI3K‐Akt signaling, Ras signaling, and extracellular matrix‐receptor interactions, the liver underwent severe metabolic dysfunction, oxidative damage, and coagulopathy after patency and at peak infection, possibly as a result of suppressed peroxisome activities and downregulated PPAR signaling. These responses largely disappeared during late infection, suggesting that the liver self‐heals after severe cholangitis. These data provide new insights into host–pathogen interactions during Eimeria infection and improve our understanding of the pathogenesis of parasitic cholangitis. [ABSTRACT FROM AUTHOR]

Leishmaniasis is a chronic global arthropod‐borne zoonotic disease produced by several species of Leishmania with cutaneous, mucocutaneous, and visceral clinical manifestations. In Spain, only Leishmania infantum has been reported so far, although other species of Leishmania, such as L. tropica and L. major, are present in surrounding countries. The aim of this work is to analyze the occurrence of Leishmania spp. infection in European wildcats (Felis silvestris) as sentinels, including their genotypic characterization. Necropsies of 18 road‐killed wildcats were conducted. Samples of ear skin and spleen were taken for DNA isolation and PCR of the highly sensitive SSU-rDNA target. Subsequent PCR tests were performed using more specific targets for the determination of Leishmania species: hsp70 and ITS1. Positive samples were sequenced, and phylogenetic trees were constructed. Seven wildcats were found positive for Leishmania spp. Based on the hsp70 and ITS1 sequences, an animal was found to be infected only with L. tropica in ear skin samples, while two cats were found to be infected with L. infantum in both the ear skin and the spleen. In one animal, a clear sequence of L. infantum ITS1 and a sequence of L. tropica hsp70 were obtained from the ear skin. Since hsp70 and ITS1 sequencing was not possible in three cats, the species of Leishmania infecting them was not determined. This is the first report of autochthonous infection with L. tropica in the Iberian Peninsula. Health care professionals, including physicians, dermatologists, and veterinarians, must be aware of this for a correct diagnosis, treatment, and management of possible coinfections. [ABSTRACT FROM AUTHOR]

Seneca Valley virus (SVV) and foot‐and‐mouth disease virus (FMDV) belong to the Picornaviridae family, which can cause similar symptoms. After infection, pigs will develop fever; loss of appetite; blister lesions on the skin and mucous membrane of the mouth, nose, and hoof; and other similar diseases, and the spread is very fast, causing major economic losses to the pig industry. Therefore, a rapid, accurate, and sensitive diagnostic method is necessary to enable rapid prevention and control measures for preventing the spread of these diseases. Here, a fluorescent immunochromatography test strip, using Eu‐doped fluorescence beads and monoclonal antibody, was developed for the simultaneous determination of FMDV and SVV. The test process for the assay could be completed in 12 min, which avoided the time cost of the current methods for FMDV/SVV detection. Under optimized conditions, the limit of detection of SVV is 5 × 104 PFU/mL, and that of FMDV is 5 × 104 PFU/mL under the Fluorescence Immunoassay Analyzer. Our assay results showed a good linear correlation with RT‐PCR installed in the clinical laboratory. The species design has a promising application prospect in the surveillance and control of the outbreak of idiopathic blister. [ABSTRACT FROM AUTHOR]

Streptococcus suis is a significant bacterial pathogen in the swine industry and represents a zoonotic threat to human health. This study aimed to investigate the prevalence, serotype distribution, and pathotypic characteristics of S. suis isolates obtained from nasopharyngeal swabs of slaughtered pigs in the high‐density swine farming region of Thailand. Among 322 swab samples, 194 samples (60.25%) were found to harbor S. suis. The most prevalent serotype was serotype 8 (7.98%), followed by 19 (7.56%), 29 (6.72%), 3 (5.88%), and 2 (5.04%), with 39.92% of isolates classified as non‐typeable. Molecular characterization revealed the presence of various clonal complexes (CCs), with CC221/234 being the most prevalent (19.15%). Human‐associated clades (HAC) were identified in 29.79% of isolates, including serotypes 2 (two isolates), 1/2 (two isolates), and 4 (four isolates) in CC233/379. Additionally, several isolates exhibited a high potential for zoonotic transmission, particularly within the CC233/379 clade, which emerged exclusively in Thailand. Molecular pathotyping uncovered challenges in differentiating pathogenic and commensal S. suis strains in healthy pigs. Despite this, surveillance and monitoring of S. suis populations are essential to track dynamics and mitigate the risk of human infections. [ABSTRACT FROM AUTHOR]

A reliable distributed covariance intersection (CI) fusion integrated navigation algorithm with information feedback during the Mars atmospheric entry is proposed to meet robust, reliable, and high-precision Mars atmospheric entry navigation strategy. A distributed integrated navigation scheme includes four independent subsystems consisting of an IMU and one radio beacon, but each subsystem is weakly observable under limited Mars entry measurements. The scalar weights are fast obtained by maximizing the information contribution of the corresponding estimate. The distributed framework based upon the CI fusion algorithm is designed by using dynamic information distribution coefficients and information feedback strategy. This distributed fusion approach could meet the lower computation cost and robust and reliable capacity and especially is beneficial to the weakly observable or unobservable subsystems during the Mars entry navigation scheme. Numerical simulations show that the proposed distributed CI fusion integrated navigation algorithm can provide consistent navigation accuracy for the Mars entry vehicle and improve the entry navigation robustness under the weakly observable navigation subsystems. [ABSTRACT FROM AUTHOR]