Transboundary and Emerging Diseases最新文献

This study describes the first outbreaks with virulent avian paramyxovirus 1 (APMV-1) since 2005 in Denmark. Both outbreaks were caused by pigeon specific variants, denoted pigeon paramyxovirus 1 (PPMV-1). The first outbreak was in June 2022 and affected captive pigeons near Næstved, in southeast Denmark, where 1053 captive birds were housed, and hereof 851 pigeons. A second and separate outbreak occurred in June 2023 in Aalborg, northwest Denmark, involving 1851 captive birds, of which 40 were pigeons. In both outbreaks, pigeons were predominantly affected, characterised by high mortality, and presented with neurological signs, along with thin-shelled eggs. Pathological and virological assessment revealed multi-systemic infections in pigeons, including neuronal and vascular endothelial tropism. Chickens were affected only in the 2022 outbreak, with reported extended hatching periods and chicks dead at hatching, and with no apparent lesions detected at both macro- and microscopic investigations. Fusion protein (F) gene sequence classified the 2022 virus isolate as genotype VI.2.1.1.2.2 and the 2023 virus as genotype XXI.1.1, with polybasic cleavage sites ¹¹²RRQKRF¹¹⁷ (2022) and ¹¹²KRQKRF¹¹⁷ (2023). However, mean death time (MDT) tests categorised both virus isolates as mesogenic, and an intracerebral pathogenicity index (ICPI) test of the 2022 virus isolate showed an ICPI index of 0.65, categorising the virus as lentogenic. This is the first report of PPMV-1 isolates with polybasic cleavage site and associated mortality in captive pigeons in Denmark. The sudden resurgence of outbreaks in Denmark after nearly two decades without similar incidents highlight the potential threat posed by circulating viruses in wild birds, such as feral pigeons, and emphasise the importance of surveillance in wild bird populations for improved risk recognition and early detection of emerging threats.

Lumpy skin disease (LSD) is a transboundary emerging disease of cattle and water buffaloes that threatens the livestock industry globally. Japan experienced its first outbreak in November 2024. This study aimed to describe the spatial and temporal characteristics of this outbreak and estimate the transmissibility using a mathematical model for within-farm transmission. The first and second cases were confirmed on dairy farms in Itoshima City, Fukuoka Prefecture, southern Japan, on November 6, 2024. Twenty-two farms were confirmed during this outbreak, with 17 cases in Itoshima City and the other two municipalities in Fukuoka Prefecture. The third case occurred in Kumamoto Prefecture on November 8, 2024, and was linked to the long-distance movement of potentially infected cattle via the livestock market from the first case on October 18, 2024. Two additional cases were detected near the third case. Control measures included isolation and voluntary culling of infected cattle; voluntary movement restrictions on infected, suspected, and apparently healthy cattle on the same premises; and voluntary suspension of the raw milk and semen shipments from infected and suspected animals. These measures were voluntary; however, no violations were reported. Vector control was achieved with insecticides and insect-proof netting. Voluntary vaccination was conducted within a 20 km radius of affected farms in Fukuoka Prefecture. Mathematical modeling of within-farm transmission dynamics revealed a transmission rate of 0.0031 (95% CI: 0.002–0.0044) per day. The basic reproduction number was 3.51 (95% CI: 2.26–4.98) based on a herd size of 49 and an infectious period of 23.1 days. Although the outbreak was geographically limited, this study highlights key epidemiological features of LSD, including its high transmission rate and long-distance transmission via cattle movement. Japan has a persisting LSD virus (LSDV)incursion risk due to recent outbreaks in Asia. Strengthening preparedness, including awareness among farmers and veterinarians, emergency vaccination plans, vector control, traceability, and quarantine protocols for cattle movement, is essential to mitigate future outbreaks.

Antimicrobial resistance (AMR) of brucellosis major causative bacteria Brucella abortus and Brucella melitensis is complicating human treatment strategies in the Mediterranean basin, where the disease was first reported and is still endemic. The current meta-analysis examines the prevalence and patterns of AMR in 119 Brucella abortus and 1344 Brucella melitensis isolates across Mediterranean countries, highlighting significant geographical disparities in resistance data. The E-test and disc diffusion were mostly used for measuring antimicrobial susceptibility, which was validated by the CLSI guidelines of Haemophilus spp. or bacteria of bioterrorism. Genotypic detection of resistance was conducted in a few studies. Despite the documented burden of brucellosis, studies on AMR remain scarce, particularly in North Africa, the Middle East, and several European Mediterranean nations. Comparative phenotypic–genotypic resistograms were reported in only a few studies, yet they are essential for understanding the mechanisms of AMR in this serious zoonotic pathogen. The analysis revealed a high overall AMR proportion (32%, 95% confidence interval [CI]: 16%–51%) with considerable heterogeneity (I² = 97%, p < 0.01). Notable differences in resistance were observed between regions, with African Mediterranean countries exhibiting the highest resistance rates (71%, 95% CI: 44%–94%) and European Mediterranean countries the lowest (9%, 95% CI: 0%–42%). Eastern Mediterranean countries exhibited higher resistance rates than their western counterparts (p = 0.11). Brucella abortus showed higher resistance (63%, 95% CI: 25%–95%) than Brucella melitensis (24%, 95% CI: 8%–43%). Isolates of bovine origin displayed the highest percentage of resistance (89%, 95% CI: 69%–100%) compared to isolates of other origins. Resistance to rifampicin and trimethoprim–sulfamethoxazole was generally low, but macrolide resistance, especially to azithromycin, was notably higher in African countries (p < 0.01). This study underscores the need for standardized AMR surveillance based on Brucella-specific validation criteria, which are lacking, improved testing methodologies, and region-specific interventions to address AMR in brucellosis, particularly in livestock, where resistance is more prevalent. The findings highlight the importance of targeted antibiotic stewardship and monitoring to mitigate the spread of resistant Brucella strains and protect public health.

Waterfowl parvoviruses (WPVs), including classical goose parvovirus (cGPV), Muscovy duck parvovirus (MDPV), Muscovy duck-origin goose parvovirus (MDGPV), and short beak and dwarfism syndrome virus (SBDSV), are significant pathogens that affect waterfowl flocks worldwide. Due to their high genetic similarity and frequent coinfections, rapid and accurate differentiation of these viruses remains challenging. In this study, we developed a multiplex TaqMan-minor groove binder (MGB) real-time PCR assay for the simultaneous detection and differentiation of cGPV, MDPV, MDGPV, and SBDSV. Specific primers and TaqMan-MGB probes were designed based on sequence alignments of the VP gene. This assay exhibited high specificity, with no cross-reactivity to other main waterfowl viruses. The detection limits of this assay were 10² copies/μL for cGPV, 10¹ copies/μL for MDPV, 10² copies/μL for MDGPV, and 10³ copies/μL for SBDSV, respectively. The standard curves exhibited strong linearity (R²≥0.995) and high amplification efficiency (89%–108%), with intra- and interassay coefficients of variation below 2.0%, indicating high repeatability and stability. Clinical testing of 337 clinical samples suspected of WPV infection demonstrated that the developed assay outperformed conventional PCR, achieving higher overall detection rates (58% vs 54%) and enhanced identification of coinfections. Epidemiological analysis revealed MDGPV as the predominant circulating strain in Muscovy ducks, with 27 samples identified as coinfected with both MDGPV and MDPV, while SBDSV showed higher prevalence in mule ducks and Pekin ducks. Notably, MDGPV was detected for the first time in goslings. These findings provide clear evidence of ongoing host restriction and potential cross-species transmission of WPVs among duck flocks. In conclusion, the multiplex TaqMan-MGB quantitative PCR (qPCR) assay developed in this study provides a rapid, sensitive, and reliable tool for the simultaneous detection and differentiation of cGPV, MDPV, MDGPV, and SBDSV. Its application is expected to enhance disease surveillance, facilitate outbreak control, and contribute to more effective control of waterfowl parvoviral diseases.

H. Zhang, F. Han, X. Shu et al., “Co-Infection of Porcine Epidemic Diarrhoea Virus and Porcine Deltacoronavirus Enhances the Disease Severity in Piglets,” Transboundary and Emerging Diseases, 2021, vol. 69: 1715–1726, https://onlinelibrary.wiley.com/doi/10.1111/tbed.14144.

In the article, there is an error in Figure 5b, introduced during the preparation of the figure. Specifically, the PDCoV and PEDV treated Ileum tissue panels contain repeated elements. The correct Figure 5b is shown below:

We apologise for this error.

Migratory birds, because of their migration and roosting characteristics, can serve as major vectors for long-distance transmission, recombination, and evolution of adenoviruses. China is one of the countries possessing the widest variety of birds in the world, with the global migration routes covering almost the entire territory. However, avian adenoviruses haven’t been systematically studied. In the current study, PCR-based molecular methods were used to characterize the adenoviruses in 38 migratory bird species from nine provinces in China from October 2020 to March 2021. Aviadenoviruses (11.4%, 79/690) were predominantly detected, followed by siadenoviruses (6.2%, 43/690) and barthadenoviruses (1.3%, 9/690). Phylogenetic analysis demonstrated about half of the aviadenoviruses clustered with Duck adenovirus 2, revealing potential association with poultry animals. A high portion (67.2%, 88/131) of the DNA polymerase sequences had <85% identity to any known sequences, indicating the potential presence of novel species, particularly in bar-headed goose where adenoviruses of all three genera were detected for the first time. The clustering of adenovirus sequences from different birds and regions in the same branch of the phylogenetic analysis suggested their close genetic relationships, indicating the transmission of adenoviruses across bird species. Host exchange and recombination events were observed, which might reflect the plasticity of these viruses and the mechanism for the emergence of novel viruses. The prevalence and characteristics of the adenoviruses in migratory birds demonstrated the wide distribution of novel adenovirus species and possible transmission between wild birds and domestic animals.

Porcine reproductive and respiratory syndrome virus (PRRSV) represents one of the major threats to the global swine industry, with its rapid evolution and antigenic variation posing persistent challenges to disease control. Based on 328 clinical samples collected from PRRSV symptomatic (respiratory disorders, reproductive failures, and high fever) pigs across 27 provinces in China during 2024–2025, this study employed open reading frame (ORF) 5 gene sequencing, complete genome sequencing of representative strains from key lineages (including a rapidly spreading NADC30-like Lineage 1.8 strain, a vaccine-related Lineage 8.7 strain, and a genetically distinct Lineage 3 strain), phylogenetic analysis, transmission dynamics analysis, intrahost single nucleotide variant (iSNV) analysis, and recombination detection to systematically reveal the molecular epidemiological characteristics and evolutionary dynamics of type II PRRSV currently circulating in China. The results demonstrated a complex pattern of coexistence among five major lineages of type II PRRSV in China, including Lineage 1.5, Lineage 1.8, Lineage 3, Lineage 5, and Lineage 8.7, with Lineage 1.8 emerging as the predominant circulating strain (48.5% of positive samples), followed by Lineage 1.5 (23.2%), while Lineages 3, 5, and 8.7 showed more restricted geographical distribution. Spatial transmission analysis identified Guangdong and Henan as key transmission nodes, forming “viral exchange centers” connecting northern and southern regions, while Hubei, Shanxi, and Jiangsu have become new viral aggregation sites. Genetic diversity analysis revealed high haplotype diversity (Hd) across all lineages except Lineage 5, with Lineage 5 showing a remarkable 106.6% increase in nucleotide diversity within 1 year, indicating rapid adaptive evolution. Tajima’s D test results revealed negative values for most lineages, with Lineage 5 and 8.7 reaching statistical significance, suggesting these viral populations have undergone recent population expansion or directional selection. Multidimensional scaling (MDS) analysis based on genetic distance revealed a potential antigenic divergence between the predominant circulating lineages (1.8 and 3) and current vaccine strains, which may compromise vaccine efficacy. In-depth analysis of three representative genomes revealed complex recombination patterns involving vaccine-related strains and identified the ORF2-ORF3 region as a potential recombination hotspot. The findings of this study provide a scientific basis for understanding the evolutionary mechanisms of type II PRRSV in China and offer important references for formulating targeted control strategies and optimizing vaccine design, which has significant value for ensuring the healthy development of China’s swine industry in the post-African swine fever era.

Examining the dissemination dynamics of foot-and-mouth disease (FMD) is critical for revising national response plans. We developed a stochastic susceptible-exposed-infected-recovered (SEIR) metapopulation model to simulate FMD outbreaks in Bolivia and explore how the national response plan impacts the dissemination among all susceptible species. We explored variations in the control strategies, mapped high-risk areas, and estimated the number of vaccinated animals during the reactive ring vaccination. Initial outbreaks ranged from 1 to 357 infected farms, with control measures implemented for up to 100 days, including control zones, a 30-day movement ban, depopulation, and ring vaccination. Combining vaccination (50–90 farms/day) and depopulation (1–2 farms/day) controlled 60.3% of outbreaks, while similar vaccination but higher depopulation rates (3–5 farms/day) controlled 62.9% and eliminated outbreaks 9 days faster. Utilizing depopulation alone controlled 56.76% of outbreaks, but had a significantly longer median duration of 63 days. Combining vaccination (25–45 farms/day) and depopulation (6–7 farms/day) was the most effective approach, eliminating all outbreaks within a median of 3 days (with a maximum of 79 days). Vaccination alone controlled only 0.6% of outbreaks and had a median duration of 98 days. Ultimately, results showed that the most effective strategy involved ring vaccination combined with depopulation, requiring a median of 925,338 animals to be vaccinated. Outbreaks were most frequent in high-density farming areas, such as Potosí, Cochabamba, and La Paz. Our results suggest that emergency ring vaccination alone cannot eliminate FMD if reintroduced in Bolivia, and combining depopulation with vaccination significantly shortens the outbreak duration. These findings provide valuable insights to inform Bolivia’s national FMD response plan, including vaccine requirements and the role of depopulation in controlling outbreaks.

Vaccine immunization is the most cost-effective way for preventing infectious diseases, and the development of safe and effective adjuvants is crucial for ensuring vaccine efficacy. Due to the advantages of high safety profile, excellent stability, and significant immune-enhancing properties, nanoemulsions have become widely used adjuvants in animal vaccines. In this study, a novel astragalus polysaccharide nanoemulsion (APSN) was developed using pseudo-ternary phase diagram method combined with phase inversion technique. The resulting nanoemulsion exhibited a hydrated diameter of approximately 78.82 nm, with favorable stability and biocompatibility. A vaccine based on FMDV virus-like particles (VLPs) was formulated using APSN as an adjuvant and was used to immunize mice and pigs. Mouse immunization results demonstrated that APSN significantly enhanced the levels of specific antibodies, IgG1, IgG2a, IFN-γ, and IL-4 induced by FMDV VLPs. Comparing with ISA-206, immunization in pigs showed that APSN paired with FMDV VLPs induced higher levels of specific antibodies, neutralizing antibodies, IL-1β, IL-4, and IFN-γ. The above results indicate that APSN is a new type of nanoemulsion adjuvant with strong potential to enhance vaccine immunogenicity, contributing valuable insights to the development of nanoadjuvant-based vaccine formulations.

Autochthonous cases of dengue in Europe are increasing. In 2023 (Lodi province) and 2024 (Fano, Pesaro and Urbino province), Italy saw the largest modern dengue outbreaks to date. Public health measures were adopted to mitigate transmission. The efficacy of these measures is unknown. We model the 2023 and 2024 dengue outbreaks to estimate the likely date of introduction of the primary case and efficacy of control measures, exploring explanations for the patterns of dengue cases for the two outbreaks. We apply a climate-driven mathematical model for Aedes albopictus and dengue virus transmission to the 2023 and 2024 outbreaks, comparing outputs to case data. The model accurately predicts the initial timeline of the Lodi dengue outbreak (R² = 0.83), with a peak in cases in late August 2023, after which the control efforts reduced transmission. The model also accurately predicts the Fano dengue outbreak (R² = 0.65), showing an increase in cases, peaking in mid-September 2024, after which there was an abrupt fall in cases. Our results suggest this can be attributed to substantial rainfall, and that public health measures may have latterly prevented a second peak in cases. The high predictive and explanatory ability of the model when applied to the Lodi and Fano outbreaks indicates that this framework may be of high value for public health decision-making for predicting the frequency and magnitude of future dengue outbreaks when coupled with real-time case data.