Viruses

10 pages, 1491 KiB

Open AccessArticle

Development of a Point-of-Care Immunochromatographic Lateral Flow Strip Assay for the Detection of Nipah and Hendra Viruses

by Jianjun Jia, Wenjun Zhu, Guodong Liu, Sandra Diederich, Bradley Pickering, Logan Banadyga and Ming Yang

Viruses 2025, 17(7), 1021; https://doi.org/10.3390/v17071021 - 21 Jul 2025

Viewed by 462

Abstract

Nipah virus (NiV) and Hendra virus (HeV), which both belong to the genus henipavirus, are zoonotic pathogens that cause severe systemic, neurological, and/or respiratory disease in humans and a variety of mammals. Therefore, monitoring viral prevalence in natural reservoirs and rapidly diagnosing cases [...] Read more.

Nipah virus (NiV) and Hendra virus (HeV), which both belong to the genus henipavirus, are zoonotic pathogens that cause severe systemic, neurological, and/or respiratory disease in humans and a variety of mammals. Therefore, monitoring viral prevalence in natural reservoirs and rapidly diagnosing cases of henipavirus infection are critical to limiting the spread of these viruses. Current laboratory methods for detecting NiV and HeV include virus isolation, reverse transcription quantitative real-time PCR (RT-qPCR), and antigen detection via an enzyme-linked immunosorbent assay (ELISA), all of which require highly trained personnel and specialized equipment. Here, we describe the development of a point-of-care customized immunochromatographic lateral flow (ILF) assay that uses recombinant human ephrin B2 as a capture ligand on the test line and a NiV-specific monoclonal antibody (mAb) on the conjugate pad to detect NiV and HeV. The ILF assay detects NiV and HeV with a diagnostic specificity of 94.4% and has no cross-reactivity with other viruses. This rapid test may be suitable for field testing and in countries with limited laboratory resources. Full article

(This article belongs to the Section General Virology)

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21 pages, 3771 KiB

Open AccessArticle

Integrated Analysis of the 2022 SARS-CoV-2 Omicron Lineage Replacement Dynamics in Connecticut, US

by Nicholas F. G. Chen, Kien Pham, Chrispin Chaguza, Rafael Lopes, Fayette Klaassen, Chaney C. Kalinich, Yale SARS-CoV-2 Genomic Surveillance Initiative, Nicholas Kerantzas, Sameer Pandya, David Ferguson, Wade Schulz, Daniel M. Weinberger, Virginia E. Pitzer, Joshua L. Warren, Nathan D. Grubaugh and Anne M. Hahn

Viruses 2025, 17(7), 1020; https://doi.org/10.3390/v17071020 - 21 Jul 2025

Viewed by 475

Abstract

In 2022, consecutive sweeps of highly transmissible SARS-CoV-2 Omicron-derived lineages (B.1.1.529*) maintained viral transmission despite extensive antigen exposure from both vaccinations and infections. To better understand Omicron variant emergence in the context of the dynamic fitness landscape of 2022, we aimed to explore [...] Read more.

In 2022, consecutive sweeps of highly transmissible SARS-CoV-2 Omicron-derived lineages (B.1.1.529*) maintained viral transmission despite extensive antigen exposure from both vaccinations and infections. To better understand Omicron variant emergence in the context of the dynamic fitness landscape of 2022, we aimed to explore putative drivers behind SARS-CoV-2 lineage replacements. Variant fitness is determined through its ability to either outrun previously dominant lineages or more efficiently circumvent host immune responses to previous infections and vaccinations. By analyzing data collected through our local genomic surveillance program from Connecticut, USA, we compared emerging Omicron lineages’ growth rates, estimated infections, effective reproductive rates, average viral copy numbers, and likelihood for causing infections in recently vaccinated individuals. We find that newly emerging Omicron lineages outcompeted dominant lineages through a combination of enhanced viral shedding or advanced immune escape depending on the population-level exposure state. This analysis integrates individual-level sequencing data with demographic, vaccination, laboratory, and epidemiological data and provides further insights into host–pathogen dynamics beyond public aggregate data. Full article

(This article belongs to the Special Issue Emerging Variants of SARS-CoV-2)

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26 pages, 24138 KiB

Open AccessReview

Insights into the Landscape of Alphavirus Receptor and Antibody Interactions

by Shishir Poudyal, Abhishek Bandyopadhyay and Richard J. Kuhn

Viruses 2025, 17(7), 1019; https://doi.org/10.3390/v17071019 - 21 Jul 2025

Viewed by 561

Abstract

Alphaviruses engage a diverse array of attachment factors and receptors during viral entry, resulting in a broad host range and disease spectrum, and thus presenting them as a major global public health concern. The development of effective antivirals against these arboviruses relies on [...] Read more.

Alphaviruses engage a diverse array of attachment factors and receptors during viral entry, resulting in a broad host range and disease spectrum, and thus presenting them as a major global public health concern. The development of effective antivirals against these arboviruses relies on a comprehensive understanding of the molecular interplay between these viruses and host cell factors, as well as the wide range of immune responses that ensue following viral infection. In this review, we present the current understanding of the complex landscape of alphavirus interaction with attachment factors and entry receptors, some of which are characterized structurally, while others are characterized biochemically. Additionally, we provide an overview of the molecular bases of epitope recognition by neutralizing and non-neutralizing antibodies against alphaviruses, and how icosahedral symmetry influences these interactions, such as occupancy and neutralization potency. We further discuss the structural bases of epitope recognition of a few pan-alphavirus antibodies, their potential therapeutic implications, and offer future perspectives on the development of effective therapeutics against clinically relevant alphaviruses. Full article

(This article belongs to the Special Issue 15-Year Anniversary of Viruses)

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14 pages, 2669 KiB

Open AccessArticle

Glutamic Acid at Position 343 in PB2 Contributes to the Virulence of H1N1 Swine Influenza Virus in Mice

by Yanwen Wang, Qiu Zhong, Fei Meng, Zhang Cheng, Yijie Zhang, Zuchen Song, Yali Zhang, Zijian Feng, Yujia Zhai, Yan Chen, Chuanling Qiao and Huanliang Yang

Viruses 2025, 17(7), 1018; https://doi.org/10.3390/v17071018 - 20 Jul 2025

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Abstract

The H1N1 swine influenza viruses CQ91 and CQ445, isolated from pigs in China, exhibited distinct virulence in mice despite sharing similar genomic constellations. CQ91 demonstrated higher pathogenicity (MLD₅₀: 5.4 log₁₀ EID₅₀) and replication efficiency in mice compared to [...] Read more.

The H1N1 swine influenza viruses CQ91 and CQ445, isolated from pigs in China, exhibited distinct virulence in mice despite sharing similar genomic constellations. CQ91 demonstrated higher pathogenicity (MLD₅₀: 5.4 log₁₀ EID₅₀) and replication efficiency in mice compared to CQ445 (MLD₅₀: 6.6 log₁₀ EID₅₀). Through reverse genetics, we found that the attenuation of CQ445 was due to a single substitution of glutamic acid (E) with lysine (K) at position 343 in the PB2 protein. Introducing the CQ445-PB2 (343K) into CQ91 significantly reduced viral replication and pathogenicity in mice, while replacing CQ445-PB2 with CQ91-PB2 (343E) restored virulence. In vitro studies showed that the K343E mutation impaired viral replication in MDCK and A549 cells and reduced polymerase activity in minigenome assays. Mechanistically, the amino acid at position 343 in the PB2 affects the transcription stage of the viral replication process. Structural modeling indicated that the charge reversal caused by E343K altered local electrostatic interactions without major conformational changes. Phylogenetic analysis revealed that PB2-343E is highly conserved (>99.9%) in human and swine H1/H3 influenza viruses, suggesting that PB2-343E confers an adaptive advantage. This study identifies PB2-343E as a critical determinant of influenza virus pathogenicity in mammals, highlighting its role in host adaptation. Full article

(This article belongs to the Section General Virology)

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20 pages, 1791 KiB

Open AccessReview

Regulation of Bombyx mori–BmNPV Protein Interactions: Study Strategies and Molecular Mechanisms

by Dan Guo, Bowen Liu, Mingxing Cui, Heying Qian and Gang Li

Viruses 2025, 17(7), 1017; https://doi.org/10.3390/v17071017 - 20 Jul 2025

Viewed by 547

Abstract

As a pivotal model organism in Lepidoptera research, the silkworm (Bombyx mori) holds significant importance in life science due to its economic value and biotechnological applications. Advancements in proteomics and bioinformatics have enabled substantial progress in characterizing the B. mori proteome. [...] Read more.

As a pivotal model organism in Lepidoptera research, the silkworm (Bombyx mori) holds significant importance in life science due to its economic value and biotechnological applications. Advancements in proteomics and bioinformatics have enabled substantial progress in characterizing the B. mori proteome. Systematic screening and identification of protein–protein interactions (PPIs) have progressively elucidated the molecular mechanisms governing key biological processes, including viral infection, immune regulation, and growth development. This review comprehensively summarizes traditional PPI detection techniques, such as yeast two-hybrid (Y2H) and immunoprecipitation (IP), alongside emerging methodologies such as mass spectrometry-based interactomics and artificial intelligence (AI)-driven PPI prediction. We critically analyze the strengths, limitations, and technological integration strategies for each approach, highlighting current field challenges. Furthermore, we elaborate on the molecular regulatory networks of Bombyx mori nucleopolyhedrovirus (BmNPV) from multiple perspectives: apoptosis and cell cycle regulation; viral protein invasion and trafficking; non-coding RNA-mediated modulation; metabolic reprogramming; and host immune evasion. These insights reveal the dynamic interplay between viral replication and host defense mechanisms. Collectively, this synthesis aims to provide a robust theoretical foundation and technical guidance for silkworm genetic improvement, infectious disease management, and the advancement of related biotechnological applications. Full article

(This article belongs to the Section Invertebrate Viruses)

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15 pages, 2357 KiB

Open AccessArticle

Development of a Novel, Highly Sensitive System for Evaluating Ebola Virus Particle Formation

by Wakako Furuyama, Miako Sakaguchi, Hanako Ariyoshi and Asuka Nanbo

Viruses 2025, 17(7), 1016; https://doi.org/10.3390/v17071016 - 19 Jul 2025

Viewed by 533

Abstract

Ebola virus (EBOV) causes severe hemorrhagic fevers in humans, and effective countermeasures remain limited. The EBOV-encoded major matrix protein VP40 is essential for viral assembly, budding, and particle release, making it a promising target for antiviral drug development. However, no approved drugs currently [...] Read more.

Ebola virus (EBOV) causes severe hemorrhagic fevers in humans, and effective countermeasures remain limited. The EBOV-encoded major matrix protein VP40 is essential for viral assembly, budding, and particle release, making it a promising target for antiviral drug development. However, no approved drugs currently target the viral particle formation process. In this study, we established a simple and highly sensitive screening system to evaluate VP40-mediated virus-like particle (VLP) formation under biosafety level −2 conditions. The system uses the HiBiT luminescence-based reporter fused to VP40, allowing for the detection of VP40 release. Our results demonstrate that the HiBiT sequence fused at the N-terminus [HiBiT-VP40 (N)] retains VP40′s ability to form VLPs, supporting its use as a functional reporter. Furthermore, we validated the system by assessing the role of Rab11-dependent trafficking in VP40-mediated budding and by evaluating the effect of nocodazole, a microtubule depolymerizer, on VLP release. This novel screening system provides a convenient and reliable platform for screening potential inhibitors targeting the late stages of EBOV infection, including viral particle formation and release. Additionally, its potential adaptability to other filoviruses suggests wide applicability in the discovery and development of additional novel therapeutic agents. Full article

(This article belongs to the Special Issue BSL4 Viruses: Understanding and Controlling Highly Infectious Pathogens)

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12 pages, 1625 KiB

Open AccessArticle

Rift Valley Fever Outbreak Investigation Associated with a Dairy Farm Abortion Storm, Mbarara District, Western Uganda, 2023

by Luke Nyakarahuka, Shannon Whitmer, Sophia Mulei, Joanita Mutesi, Jimmy Baluku, Jackson Kyondo, Amy Whitesell, Carson Telford, Alex Tumusiime, Calvin Richie Torach, Dianah Namanya, Mariam Nambuya, Dominic Muhereza, Zainah Kabami, Annet Nankya, David Muwanguzi, Francis Mugabi, Nelson Wandera, Rose Muhindo, Joel M. Montgomery, Julius J. Lutwama, Stephen Karabyo Balinandi, John D. Klena and Trevor R. Shoemaker Show full author list Hide full author list

Viruses 2025, 17(7), 1015; https://doi.org/10.3390/v17071015 - 19 Jul 2025

Viewed by 555

Abstract

In Africa, Rift Valley Fever poses a substantial risk to animal health, and human cases occur after contact with infected animals or their tissues. RVF has re-emerged in Uganda after nearly five decades, with multiple outbreaks recorded since 2016. We investigated a unique [...] Read more.

In Africa, Rift Valley Fever poses a substantial risk to animal health, and human cases occur after contact with infected animals or their tissues. RVF has re-emerged in Uganda after nearly five decades, with multiple outbreaks recorded since 2016. We investigated a unique RVF outbreak associated with an animal abortion storm of 30 events and human cases on a dairy farm in Mbarara District, Western Uganda, in February 2023. Genomic analysis was performed, comparing animal and human RVF viruses (RVFV) circulating in the region. A cluster of thirteen human RVF cases and nine PCR-positive animals could directly be linked with the abortion storm. Overall, during the year 2023, we confirmed 61 human RVFV cases across Uganda, 88.5% of which were reported to have had direct contact with livestock, and a high case fatality rate of 31%. We recommend implementing extensive health education programs in affected communities and using sustainable mosquito control strategies to limit transmission in livestock, coupled with initiating animal vaccination trials in Uganda. Full article

(This article belongs to the Special Issue Emerging Highlights in the Study of Rift Valley Fever Virus)

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14 pages, 3463 KiB

Open AccessArticle

The Renin–Angiotensin System Modulates SARS-CoV-2 Entry via ACE2 Receptor

by Sophia Gagliardi, Tristan Hotchkin, Hasset Tibebe, Grace Hillmer, Dacia Marquez, Coco Izumi, Jason Chang, Alexander Diggs, Jiro Ezaki, Yuichiro J. Suzuki and Taisuke Izumi

Viruses 2025, 17(7), 1014; https://doi.org/10.3390/v17071014 - 19 Jul 2025

Viewed by 626

Abstract

The renin–angiotensin system (RAS) plays a central role in cardiovascular regulation and has gained prominence in the pathogenesis of Coronavirus Disease 2019 (COVID-19) due to the critical function of angiotensin-converting enzyme 2 (ACE2) as the entry receptor for severe acute respiratory syndrome coronavirus [...] Read more.

The renin–angiotensin system (RAS) plays a central role in cardiovascular regulation and has gained prominence in the pathogenesis of Coronavirus Disease 2019 (COVID-19) due to the critical function of angiotensin-converting enzyme 2 (ACE2) as the entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Angiotensin IV, but not angiotensin II, has recently been reported to enhance the binding between the viral spike protein and ACE2. To investigate the virological significance of this effect, we developed a single-round infection assay using SARS-CoV-2 viral-like particles expressing the spike protein. Our results demonstrate that while angiotensin II does not affect viral infectivity across concentrations ranging from 40 nM to 400 nM, angiotensin IV enhances viral entry at a low concentration but exhibits dose-dependent inhibition at higher concentrations. These findings highlight the unique dual role of angiotensin IV in modulating SARS-CoV-2 entry. In silico molecular docking simulations indicate that angiotensin IV was predicted to associate with the S1 domain near the receptor-binding domain in the open spike conformation. Given that reported plasma concentrations of angiotensin IV range widely from 17 pM to 81 nM, these levels may be sufficient to promote, rather than inhibit, SARS-CoV-2 infection. This study identifies a novel link between RAS-derived peptides and SARS-CoV-2 infectivity, offering new insights into COVID-19 pathophysiology and informing potential therapeutic strategies. Full article

(This article belongs to the Section Human Virology and Viral Diseases)

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17 pages, 334 KiB

Open AccessArticle

Maternal Obesity Modifies the Impact of Active SARS-CoV-2 Infection on Placental Pathology

by Francisca Carmo, Carla Ramalho, Susana Guimarães and Fátima Martel

Viruses 2025, 17(7), 1013; https://doi.org/10.3390/v17071013 - 18 Jul 2025

Viewed by 375

Abstract

Background: Obesity during pregnancy is associated with an elevated risk of severe COVID-19, including higher rates of maternal complications, intensive care admission, and adverse neonatal outcomes. The impact of combination of SARS-CoV-2 infection and maternal obesity in placental pathology has not been properly [...] Read more.

Background: Obesity during pregnancy is associated with an elevated risk of severe COVID-19, including higher rates of maternal complications, intensive care admission, and adverse neonatal outcomes. The impact of combination of SARS-CoV-2 infection and maternal obesity in placental pathology has not been properly investigated. Aim: To compare the histopathological changes in the placenta induced by active SARS-CoV-2 infection in obese and non-obese patients. Methods: This retrospective cohort study included human placentas from non-obese women and pre-gestationally obese women with active SARS-CoV-2 infection (SARS and OB+SARS, respectively), and placentas from non-obese women and pre-gestationally obese women without SARS-CoV-2 infection (control and OB, collected in the post- and pre-pandemic periods, respectively). Results: A higher (50%) occurrence of ischemic injury and subchorionic fibrin deposits and a 15× higher risk of occurrence of these lesions were found in the OB+SARS group, in relation to control. In contrast, a 10% lower risk of developing chorangiosis in the OB+SARS group than the OB group was observed. Conclusions: An increased risk of lesions related to both maternal and fetal malperfusion and ischemic injury and a lower risk for chorangiosis exist in placentas from obese women affected by SARS-CoV-2 infection. Importantly, these differences were not observed in placentas from non-obese women. Full article

(This article belongs to the Special Issue SARS-CoV-2, COVID-19 Pathologies, Long COVID, and Anti-COVID Vaccines)

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12 pages, 1313 KiB

Open AccessArticle

CrAssphage as a Human Enteric Viral Contamination Bioindicator in Marketed Bivalve Mollusks

by Isabella Rodrigues Negreiros, Natália Lourenço dos Santos, Bruna Barbosa de Paula, Bruna Lopes Figueiredo, Marcelo Luiz Lima Brandão, José Paulo Gagliardi Leite, Marize Pereira Miagostovich and Carina Pacheco Cantelli

Viruses 2025, 17(7), 1012; https://doi.org/10.3390/v17071012 - 18 Jul 2025

Viewed by 385

Abstract

CrAssphage, a bacteriophage that infects human gut-associated Bacteroides spp., has emerged as a potential anthropogenic fecal pollution indicator in environmental matrices. This study investigated the presence and concentration of crAssphages in bivalve mollusks (oysters and mussels) marketed in three cities in the state [...] Read more.

CrAssphage, a bacteriophage that infects human gut-associated Bacteroides spp., has emerged as a potential anthropogenic fecal pollution indicator in environmental matrices. This study investigated the presence and concentration of crAssphages in bivalve mollusks (oysters and mussels) marketed in three cities in the state of Rio de Janeiro, Brazil, sampled from January to December 2022. CrAssphages were detected during the study period in 66.7% (48/72) of sampled oysters and 54.8% (34/62) of sampled mussels, at median concentrations of 1.9 × 10⁴ and 4.2 × 10⁴ genome copies (GC)/g, respectively. These levels were 1–2 log₁₀ higher than those observed for major human enteric viruses, including norovirus genogroups GI and GII, sapovirus, human mastadenovirus (HAdV), rotavirus A, human astrovirus (HAstV), and hepatitis A virus. CrAssphage specificity and sensitivity were calculated for all viruses. Moderate correlations between crAssphage (log₁₀ GC/g) and norovirus GI and GII, HAdV, SaV, and HAstV (Spearman’s rho = 0.581–0.464, p < 0.001) were observed in mussels. Altogether, the data support the use of crAssphage as a molecular indicator of human viral contamination in shellfish, with potential application in routine environmental and food safety monitoring in production areas. Full article

(This article belongs to the Special Issue Role of Bacteriophage in Intestine Microbial Communities)

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14 pages, 1708 KiB

Open AccessArticle

Investigation of the Mouse Infection Model for Echovirus 18

by Lei Xiang, Linlin Zhai, Guanyong Ou, Wei Zhao, Yang Yang and Chenguang Shen

Viruses 2025, 17(7), 1011; https://doi.org/10.3390/v17071011 - 18 Jul 2025

Viewed by 382

Abstract

Echovirus 18, a member of the B group of enteroviruses, is a significant etiological agent of aseptic meningitis and viral encephalitis in children. In this study, we investigated the pathogenicity of E18 by establishing a mouse infection model after comparing various mouse strains [...] Read more.

Echovirus 18, a member of the B group of enteroviruses, is a significant etiological agent of aseptic meningitis and viral encephalitis in children. In this study, we investigated the pathogenicity of E18 by establishing a mouse infection model after comparing various mouse strains and injection methods. Two-day-old IFNAR1 knockout mice infected with clinical isolates of E18 exhibited symptoms such as lethargy, hind limb paralysis, and even mortality. Similarly, some two-day-old C57BL/6J mice displayed comparable symptoms; however, the incidence was lower than that observed in IFNAR1 knockout mice. No similar symptoms were noted in any Balb/c mice. Significant pathological changes were observed in skeletal muscle, brain tissue, and other organs of symptomatic mice; among these tissues, skeletal muscle demonstrated the highest viral load. The established infection model using two-day-old IFNAR1 knockout mice provides valuable insights into further investigations regarding its pathological injury mechanisms as well as the protective effects conferred by antibodies. Full article

(This article belongs to the Section Animal Viruses)

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16 pages, 2780 KiB

Open AccessArticle

Impact of Wheat Resistance Genes on Wheat Curl Mite Fitness and Wheat Streak Mosaic Dynamics Under Single and Mixed Infections

by Saurabh Gautam and Kiran R. Gadhave

Viruses 2025, 17(7), 1010; https://doi.org/10.3390/v17071010 - 18 Jul 2025

Viewed by 404

Abstract

The wheat curl mite (WCM, Aceria tosichella Keifer), a complex of eriophyid mite species, transmits wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV), which in single or mixed infections cause wheat streak mosaic (WSM) disease—a major threat to wheat production across [...] Read more.

The wheat curl mite (WCM, Aceria tosichella Keifer), a complex of eriophyid mite species, transmits wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV), which in single or mixed infections cause wheat streak mosaic (WSM) disease—a major threat to wheat production across the U.S. Great Plains. Resistant wheat cultivars bearing Cmc3 and Cmc4 (targeting WCM), Wsm1 and Wsm2 (targeting WSMV), and Wsm1 (targeting TriMV) are widely used to manage this pest–pathogen complex. However, comprehensive studies investigating how these resistance mechanisms influence both vector biology and virus transmission remain scarce. To address this gap, we evaluated disease development and WCM fitness across nine wheat cultivars with differential resistance profiles under single and mixed infections of WSMV and TriMV. We found strong viral synergy in co-infected plants, with TriMV accumulation markedly enhanced during mixed infections, irrespective of host genotype. Symptom severity and virus titers (both WSMV and TriMV) were highest in the cultivars carrying Wsm2, suggesting a potential trade-off in resistance effectiveness under mixed infection pressure. While mite development time (egg to adult) was unaffected by host genotype or infection status, mite fecundity was significantly reduced on infected plants carrying Wsm1 or Wsm2, but not on those with Cmc3 and Cmc4. Notably, virus accumulation in mites was reduced on the cultivars with Cmc3 and Cmc4, correlating with virus titers in the host tissues. Our findings highlight the complex interplay between host resistance, virus dynamics, and vector performance. Cultivars harboring Cmc3 and Cmc4 may offer robust field-level protection by simultaneously suppressing mite reproduction and limiting virus accumulation in both plant and vector. Full article

(This article belongs to the Special Issue Molecular and Biological Virus-Plant-Insect Vector Interactions)

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15 pages, 1064 KiB

Open AccessArticle

Overexpression of Interleukin-17 Modulates Responses to Marek’s Disease Virus Infection and Tumor Formation in Chickens

by Nitish Boodhoo, Katherine Blake, Fatemeh Fazel, Janan Shoja Doost and Shayan Sharif

Viruses 2025, 17(7), 1009; https://doi.org/10.3390/v17071009 - 18 Jul 2025

Viewed by 408

Abstract

Marek’s Disease Virus (MDV) is a highly contagious pathogen in chickens, resulting in immunosuppression and T-cell lymphomas. Understanding the role of host cytokines in MDV pathogenesis is crucial for developing effective interventions. This study investigated the in vivo effects of overexpressing avian interleukin-17 [...] Read more.

Marek’s Disease Virus (MDV) is a highly contagious pathogen in chickens, resulting in immunosuppression and T-cell lymphomas. Understanding the role of host cytokines in MDV pathogenesis is crucial for developing effective interventions. This study investigated the in vivo effects of overexpressing avian interleukin-17 (IL-17) in Marek’s disease virus infection model and its impact on T-cell populations. We utilized a recombinant pCDNA3.1 plasmid that expresses IL-17 at days 4 and 10 post-MDV infection in chickens. Our findings demonstrate that IL-17 overexpression significantly enhanced MDV replication. However, treatment with the plasmid expressing IL-17 led to a reduction in MD disease severity. Additionally, IL-17 treatment markedly altered the frequency of CD4+ and CD8α+ αβ T-cells. Specifically, at 21-dpi, there was an increase in CD3+ CD8α+ αβ T cells and a decrease in CD3+ CD4+ αβ T-cells within the spleen of chickens treated with the plasmid expressing IL-17. These modulatory effects suggest a possible mechanism by which IL-17 facilitates immune system cell activation and enhances viral persistence. This study underscores the pivotal role of IL-17 in MDV infection dynamics and offers. Full article

(This article belongs to the Special Issue Marek's Disease Virus)

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22 pages, 3860 KiB

Open AccessArticle

Spatiotemporal Dynamics of Emerging Foot-and-Mouth Disease, Bluetongue, and Peste Des Petits Ruminants in Algeria

by Ilhem Zouyed, Sabrina Boussena, Nacira Ramdani, Houssem Eddine Damerdji, Julio A. Benavides and Hacène Medkour

Viruses 2025, 17(7), 1008; https://doi.org/10.3390/v17071008 - 17 Jul 2025

Viewed by 630

Abstract

Foot-and-mouth disease (FMD), bluetongue (BT), and Peste des Petits Ruminants (PPR) are major emerging and re-emerging viral infections affecting ruminants. These diseases can threaten livestock health, food security, and economic stability in low- and middle-income countries, including Algeria. However, their dynamics remain mostly [...] Read more.

Foot-and-mouth disease (FMD), bluetongue (BT), and Peste des Petits Ruminants (PPR) are major emerging and re-emerging viral infections affecting ruminants. These diseases can threaten livestock health, food security, and economic stability in low- and middle-income countries, including Algeria. However, their dynamics remain mostly unknown, limiting the implementation of effective preventive and control measures. We analyzed outbreak data reported by Algerian veterinary authorities and the WAHIS database from 2014 to 2022 for FMD; from 2006 to 2020 for BT; and from 2011 to 2022 for PPR to investigate their spatiotemporal patterns and environmental drivers. Over these periods, Algeria reported 1142 FMD outbreaks (10,409 cases; 0.16/1000 incidence), 167 BT outbreaks (602 cases; 0.018/1000), and 222 PPR outbreaks (3597 cases; 0.096/1000). Small ruminants were the most affected across all diseases, although cattle bore the highest burden of FMD. BT primarily impacted sheep, and PPR showed a higher incidence in goats. Disease peaks occurred in 2014 for FMD, 2008 for BT, and 2019 for PPR. Spatial analyses revealed distinct ecological hotspots: sub-humid and semi-arid zones for FMD and BT, and semi-arid/Saharan regions for PPR. These patterns may be influenced by species susceptibility, animal movement, trade, and climatic factors such as temperature and rainfall. The absence of consistent temporal trends and the persistence of outbreaks suggest multiple drivers, including insufficient vaccination coverage, under-reporting, viral evolution, and environmental persistence. Our findings underscore the importance of targeted species- and region-specific control strategies, including improved surveillance, cross-border coordination, and climate-informed risk mapping. Strengthening One Health frameworks will be essential to mitigate the re-emergence and spread of these diseases. Full article

(This article belongs to the Special Issue Emerging Microbes, Infections and Spillovers, 2nd Edition)

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8 pages, 764 KiB

Open AccessCommunication

A Strand-Specific Quantitative RT-PCR Method for Detecting vRNA, cRNA, and mRNA of H7N9 Avian Influenza Virus in a Mouse Model

by Bo Wang, Guangwen Wang, Yi-han Wang, Xuwei Liu, Manman Li, Huihui Kong, Hualan Chen, Li Jiang and Chengjun Li

Viruses 2025, 17(7), 1007; https://doi.org/10.3390/v17071007 - 17 Jul 2025

Viewed by 449

Abstract

Avian influenza virus (AIV) remains a persistent threat to both the poultry industry and human health. Among the AIV subtypes posing public health threats, H7N9 AIV is responsible for five epidemic waves of human infection in China. Here, a detection system based on [...] Read more.

Avian influenza virus (AIV) remains a persistent threat to both the poultry industry and human health. Among the AIV subtypes posing public health threats, H7N9 AIV is responsible for five epidemic waves of human infection in China. Here, a detection system based on a mouse model was established, which can simultaneously and quantitatively analyze the dynamic changes in the viral genomic RNA (vRNA), complementary RNA (cRNA), and messenger RNA (mRNA) of H7N9 AIV by using reverse transcription primers with tag sequences to reverse transcribe the three species of RNAs into corresponding cDNA templates, which are then absolutely quantified using the TaqMan quantitative PCR method. This system specifically targets the PB2 and NA genes and, for the first time, enables a spatiotemporal analysis of all three viral RNA species within an animal model. Our results revealed that H7N9 AIV exhibits characteristic replication kinetics, with all three species of viral RNAs showing a rapid increase followed by a certain degree of decline. This system offers a powerful tool for us to further advance our understanding of the replication dynamics of AIV in mice. Full article

(This article belongs to the Special Issue Influenza and Other Respiratory Viruses: Prevention, Diagnosis, Treatment: 2nd Edition)

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34 pages, 2326 KiB

Open AccessReview

Non-Coding RNAs and Immune Evasion in Human Gamma-Herpesviruses

by Tablow S. Media, Laura Cano-Aroca and Takanobu Tagawa

Viruses 2025, 17(7), 1006; https://doi.org/10.3390/v17071006 - 17 Jul 2025

Viewed by 457

Abstract

Herpesviruses are DNA viruses that evade the immune response and persist as lifelong infections. Human gamma-herpesviruses Epstein–Barr virus (EBV) and Kaposi’s sarcoma herpesvirus (KSHV) are oncogenic; they can lead to cancer. Oncogenic viruses are responsible for 10–15% of human cancer development, which can [...] Read more.

Herpesviruses are DNA viruses that evade the immune response and persist as lifelong infections. Human gamma-herpesviruses Epstein–Barr virus (EBV) and Kaposi’s sarcoma herpesvirus (KSHV) are oncogenic; they can lead to cancer. Oncogenic viruses are responsible for 10–15% of human cancer development, which can have poor prognoses. Non-coding RNAs (ncRNAs) are RNAs that regulate gene expression without encoding proteins, and are being studied for their roles in viral immune evasion, infection, and oncogenesis. ncRNAs are classified by their size, and include long non-coding RNAs, microRNAs, and circular RNAs. EBV and KSHV manipulate host ncRNAs, and encode their own ncRNAs, regulating host processes and immune responses. Viral ncRNAs regulate host functions by post-transcriptionally modifying host RNAs, and by serving as mimics of other host RNAs, promoting immune evasion. ncRNAs in gamma-herpesvirus infection are also important for tumorigenesis, as dampening immune responses via ncRNAs can upregulate pro-tumorigenic pathways. Emerging topics such as RNA modifications, target-directed miRNA degradation, competing endogenous RNA networks, and lncRNA/circRNA–miRNA interactions provide new insights into ncRNA functions. This review compares ncRNAs and the mechanisms of viral immune evasion in EBV and KSHV, while also expanding on recent developments in the roles of ncRNAs in immune evasion, viral infection, and oncogenesis. Full article

(This article belongs to the Special Issue Understanding the Oncogenesis of Human Herpesviruses through Their Critical Comparisons)

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14 pages, 958 KiB

Open AccessArticle

Serum sICAM-1 and Galectin-3 Levels in Diabetic Patients with COVID-19

by Busra Karahan, Dogan Nasir Binici, Omer Karasahin, Sibel İba Yilmaz, Ahmet Kiziltunc and Filiz Mercantepe

Viruses 2025, 17(7), 1005; https://doi.org/10.3390/v17071005 - 17 Jul 2025

Viewed by 403

Abstract

Introduction: This study aimed to evaluate the diagnostic and prognostic value of soluble intercellular adhesion molecule-1 (sICAM-1) and galectin-3 in patients with type 2 diabetes mellitus (T2D) diagnosed with coronavirus disease 2019 (COVID-19). Participants and Method: This prospective observational study included 45 adult [...] Read more.

Introduction: This study aimed to evaluate the diagnostic and prognostic value of soluble intercellular adhesion molecule-1 (sICAM-1) and galectin-3 in patients with type 2 diabetes mellitus (T2D) diagnosed with coronavirus disease 2019 (COVID-19). Participants and Method: This prospective observational study included 45 adult patients (≥18 years) with T2D and confirmed COVID-19 who were followed in the Infectious Diseases and Clinical Microbiology departments between May and June 2022. The control group consisted of 45 healthy volunteers without chronic illness who were presented to the internal medicine outpatient clinic. In addition to routine laboratory biomarkers assessed at hospital admission, the serum levels of sICAM-1 and galectin-3 were measured via ELISA kits. Results: The median age of the patients was 66 years (range: 41–77), and 23 (51.1%) were male. Hypertension was the most common comorbidity in addition to diabetes. Compared with those in the control group, the serum levels of both galectin-3 and sICAM-1 were significantly elevated in patients with COVID-19 and T2D (p < 0.001). However, there was no significant difference in galectin-3 or sICAM-1 levels between survivors and nonsurvivors (p = 0.240 and p = 0.266, respectively). Conclusion: Galectin-3 and sICAM-1 demonstrated stronger diagnostic utility than conventional biomarkers in T2D patients with COVID-19. The elevated levels of these markers may reflect the underlying systemic inflammation observed in diabetic patients with COVID-19. The strong correlation between galectin-3 and sICAM-1 suggests a potential link in their inflammatory regulation, although causality cannot be inferred. Full article

(This article belongs to the Special Issue COVID-19 Complications and Co-infections)

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9 pages, 207 KiB

Open AccessArticle

Innovating Quality Control and External Quality Assurance for HIV-1 Recent Infection Testing: Empowering HIV Surveillance in Lao PDR

by Supaporn Suparak, Kanokwan Ngueanchanthong, Petai Unpol, Siriphailin Jomjunyoung, Wipawee Thanyacharern, Sirilada Pimpa Chisholm, Nitis Smanthong, Pojaporn Pinrod, Thitipong Yingyong, Phonepadith Xangsayarath, Sinakhone Xayadeth, Virasack Somoulay, Theerawit Tasaneeyapan, Somboon Nookhai, Archawin Rojanawiwat and Sanny Northbrook

Viruses 2025, 17(7), 1004; https://doi.org/10.3390/v17071004 - 17 Jul 2025

Viewed by 861

Abstract

Quality assurance programs are critical to ensuring the consistency and reliability of point-of-care surveillance test results. In 2022, we launched Laos’ inaugural quality control (QC) and external quality assessment (EQA) program for national HIV recent infection surveillance. Our study aims to implement the [...] Read more.

Quality assurance programs are critical to ensuring the consistency and reliability of point-of-care surveillance test results. In 2022, we launched Laos’ inaugural quality control (QC) and external quality assessment (EQA) program for national HIV recent infection surveillance. Our study aims to implement the first QC and EQA program for national HIV recent infection surveillance in Laos, utilizing non-infectious dried tube specimens (DTS) for quality control testing. This initiative seeks to monitor and assure the quality of HIV infection surveillance. We employed the Asante HIV-1 Rapid Test for Recent Infection (HIV-1 RTRI) point-of-care kit, using plasma specimens from the Thai Red Cross Society to create dried tube specimens (DTS). The DTS panels, including HIV-1 negative, HIV-1 recent, and HIV-1 long-term samples, met ISO 13528:2022 standards to ensure homogeneity and stability. These panels were transported from the Thai National Institute of Health (Thai NIH) to the Laos National Center for Laboratory and Epidemiology (NCLE) and subsequently shipped to 12 remote laboratories at ambient temperature. The laboratory results were electronically transmitted to Thai NIH 15 days after receiving the panel for performance analysis. The concordance results with the sample types were scored, and laboratories that achieved 100% concordance across all sample panels were considered to have satisfactorily met the established standards. Almost all laboratories demonstrated satisfactory results with 100% concordance across all sample panels during all three rounds of QC: 11 out of 12 (92%) in June, 10 out of 12 (83%) in July, and 11 out of 12 (91%) in August. The two rounds of EQA performed in June and August 2022 were satisfied by 8 out of 11 (72%) and 5 out of 10 (50%) laboratories, respectively. QC and EQA monitoring identified errors such as testing protocol mistakes and insufficient DTS panel dissolution, leading to improvements in HIV recency testing quality. Laboratories that reported errors were corrected and implemented further preventive actions. The QC and EQA program for HIV-1 RTRI identified errors in HIV recent infection testing. Implementing a specialized QC and EQA program for DTS marks a significant advancement in improving the accuracy and consistency of HIV recent infection surveillance. Continuous assessment is vital for addressing recurring issues. Full article

(This article belongs to the Section Human Virology and Viral Diseases)

22 pages, 652 KiB

Open AccessReview

Laboratory Diagnosis of Hendra and Nipah: Two Emerging Zoonotic Diseases with One Health Significance

by Shaun van den Hurk, Aurelle Yondo and Binu T. Velayudhan

Viruses 2025, 17(7), 1003; https://doi.org/10.3390/v17071003 - 17 Jul 2025

Viewed by 551

Abstract

Hendra virus (HeV) and Nipah virus (NiV) are two highly pathogenic RNA viruses with zoonotic potential, which can cause severe diseases with high mortality rates (50–100%) in humans and animals. Given this context, these viruses are classified as Biosafety Level 4 (BSL-4) pathogens, [...] Read more.

Hendra virus (HeV) and Nipah virus (NiV) are two highly pathogenic RNA viruses with zoonotic potential, which can cause severe diseases with high mortality rates (50–100%) in humans and animals. Given this context, these viruses are classified as Biosafety Level 4 (BSL-4) pathogens, thus limiting research studies. Despite the high case fatalities, there are currently no human vaccines available for either virus, owing in part to the limitations in research and hesitancy in funding. In the absence of widespread vaccination, diagnostic tests are crucial for the rapid identification of cases and disease surveillance. This review synthesizes current knowledge on the epidemiology, transmission dynamics, and pathogenesis of NiV and HeV to contextualize a detailed assessment of the available diagnostic tools. We examined molecular and serological assays, including RT-PCR, ELISA, and LAMP, highlighting sample sources, detection windows, and performance. Diagnostic considerations across human and animal hosts are discussed, with emphasis on outbreak applicability and field-readiness, given the need for diagnostic assays that are suitable for use in low-income areas. Further development of diagnostic assays, including isothermal amplification tests and other next-generation approaches, is recommended to fill the gap in rapid, point-of-care diagnostics. Full article

(This article belongs to the Section Human Virology and Viral Diseases)

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18 pages, 1324 KiB

Open AccessReview

Age Matters: Key Contributors to Interferon Toxicity in Infants During Influenza Virus Infection

by Abigail P. Onufer and Alison J. Carey

Viruses 2025, 17(7), 1002; https://doi.org/10.3390/v17071002 - 17 Jul 2025

Viewed by 616

Abstract

Respiratory viral infections are a leading cause of early childhood hospitalizations in the United States. Neonatal immune responses are reliant on innate mechanisms during the first few months of life. Interferons (IFNs) are a key component of this response. These antiviral cytokines are [...] Read more.

Respiratory viral infections are a leading cause of early childhood hospitalizations in the United States. Neonatal immune responses are reliant on innate mechanisms during the first few months of life. Interferons (IFNs) are a key component of this response. These antiviral cytokines are produced early in infection and aid in viral control and clearance. Although generally considered protective in the setting of respiratory viral infections, the recent literature has suggested that IFNs may exacerbate disease. In the process of promoting an antiviral environment, IFNs impede cell proliferation, contribute to pulmonary barrier disruption, and generate reactive oxygen species. This is not tolerated in the rapidly developing neonatal lung. Therefore, IFNs contribute to pathogenesis in the influenza-infected neonate. This review focuses on the potential mechanisms that drive IFN-induced toxicity in neonates and prospective therapeutics to mitigate this toxicity. Full article

(This article belongs to the Special Issue Interferon Signaling in Viral Pathogenesis)

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12 pages, 2134 KiB

Open AccessArticle

Genomic Epidemiology of SARS-CoV-2 in Ukraine from May 2022 to March 2024 Reveals Omicron Variant Dynamics

by Anna Iaruchyk, Jason Farlow, Artem Skrypnyk, Serhii Matchyshyn, Alina Kovalchuk, Iryna Demchyshyna, Mykhailo Rosada, Aron Kassahun Aregay and Jarno Habicht

Viruses 2025, 17(7), 1000; https://doi.org/10.3390/v17071000 - 17 Jul 2025

Viewed by 823

Abstract

In Ukraine, SARS-CoV-2 detection and national genomic surveillance have been complicated by full-scale war, limited resources, and varying levels of public health infrastructure impacted across the country. Following the Spring of 2022, only a paucity of data have been reported describing the prevalence [...] Read more.

In Ukraine, SARS-CoV-2 detection and national genomic surveillance have been complicated by full-scale war, limited resources, and varying levels of public health infrastructure impacted across the country. Following the Spring of 2022, only a paucity of data have been reported describing the prevalence and variant dynamics of SARS-CoV-2 in the country. Comparative whole genome analysis has overtaken diagnostics as the new gold standard for detecting and tracing emerging variants while showing utility to rapidly inform diagnostics, vaccine strategies, and health policy. Herein, we provide an updated report characterizing the dynamics and prevalence of SARS-CoV-2 in Ukraine from 1 May 2022 to 31 March 2024. The present study extends previous reports for disease incidence Waves 1–4 in Ukraine with the addition herein of Waves 5, 6, and 7, occurring from August to November 2022 (Wave 5), February to May 2023 (Wave 6), and October 2023 to January 2024 (Wave 7). During the study period, the national Case Fatality Rate (CFR) fluctuated between 0.46% and 1.74%, indicating a consistent yet modest rate when compared to the global average. The epidemiological dynamics of Variants of Concern (VOCs) in Ukraine reflected global patterns over this period, punctuated by the rise of the BA.5 lineage and its subsequent replacement by the Omicron subvariants XBB and JN.1. Our analysis of variant dispersal patterns revealed multiple potential spatiotemporal introductions into Ukraine from Europe, Asia, and North America. Our results highlight the importance of ongoing genomic surveillance to monitor variant dynamics and support global efforts to control and mitigate COVID-19 disease risks as new variants arise. Full article

(This article belongs to the Section Coronaviruses)

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13 pages, 489 KiB

Open AccessArticle

Seroprevalence of Equine Influenza Virus Antibodies in Horses from Four Localities in Colombia

by Juliana Gonzalez-Obando, Jeiczon Jaimes-Dueñez, Angélica Zuluaga-Cabrera, Jorge E. Forero, Andrés Diaz, Carlos Rojas-Arbeláez and Julian Ruiz-Saenz

Viruses 2025, 17(7), 999; https://doi.org/10.3390/v17070999 - 16 Jul 2025

Viewed by 522

Abstract

Equine influenza is a highly contagious disease caused by the equine influenza virus (EIV). The occurrence of EIV outbreaks in America is associated with low levels of vaccination coverage. In Colombia, no seroprevalence evaluation has been carried out to estimate the distribution of [...] Read more.

Equine influenza is a highly contagious disease caused by the equine influenza virus (EIV). The occurrence of EIV outbreaks in America is associated with low levels of vaccination coverage. In Colombia, no seroprevalence evaluation has been carried out to estimate the distribution of the virus within the country. Our aim was to perform a sero-epidemiological survey of equine influenza infections and to identify associated risk factors in horses from four departments of Colombia. Serological testing was carried out by using an ELISA for the detection of IgG antibodies against the influenza A virus. The evaluation of epidemiological variables, clinical manifestations, and vaccination history was carried out through the application of a data collection instrument. Among the 385 horses analyzed, 27% of the samples tested positive, with a higher prevalence in Study 1 from horses with respiratory symptoms (40.4%) than in Study 2 from horses without clinical signs (16.1%). Only horses housed in stables had higher odds of testing positive. The study also revealed that unvaccinated horses were 68% less likely to test positive than vaccinated horses were. This research highlights a significant gap in vaccination coverage and the presence of antibodies even in asymptomatic horses. Management factors such as activity type and housing should be considered when strategies for EIV prevention are developed. Full article

(This article belongs to the Special Issue Viral Diseases of Livestock and Diagnostics, 2nd Edition)

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14 pages, 4342 KiB

Open AccessReview

Spatiotemporal Distribution and Risk Factors of African Swine Fever Outbreak Cases in Uganda for the Period 2010–2023

by Eddie M. Wampande, Robert Opio, Simon P. Angeki, Corrie Brown, Bonto Faburay, Rose O. Ademun, Kenneth Ssekatawa, David D. South, Charles Waiswa and Peter Waiswa

Viruses 2025, 17(7), 998; https://doi.org/10.3390/v17070998 - 16 Jul 2025

Viewed by 361

Abstract

This paper describes the spatiotemporal distribution and risk factors of African Swine Fever (ASF) in Uganda for the period of 2010 through 2023. The study utilized a comprehensive dataset from monthly reports (2010–2023) from District Veterinary Officers (DVOs), the Ministry of Agriculture, Animal [...] Read more.

This paper describes the spatiotemporal distribution and risk factors of African Swine Fever (ASF) in Uganda for the period of 2010 through 2023. The study utilized a comprehensive dataset from monthly reports (2010–2023) from District Veterinary Officers (DVOs), the Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), and the Food and Agriculture Organization, Uganda. Using GPS coordinates, ASF cases were mapped using QGIS to show ASF distribution and spread in Uganda. Moran’s I analysis was used to delineate clusters of ASF. A total of 1521 ASF cases were recorded. The data show that cases of ASF were disseminated throughout the country, with more cases of ASF documented in the central region and border districts (hotspots for ASF), and few cases were reported in Acholi, Karamoja, and Lango, Ankole, West Nile, and Kigezi sub-regions. The time series analysis revealed incidences of ASF disease occurring year-round; notable peak cases were observed in some districts, and districts with ≥30,000 pigs reported higher cases of ASF. The Moran’s I (≥1) analysis showed that ASF is either aggregated (p = 0.01), especially in central districts bordering Tanzania and lake shores, or sporadic in occurrence. The disease was present in 66% of the districts, with ASF occurring throughout the year. More cases were aggregated in central and border districts and districts with large pig populations (≥30,000). Sporadic cases were reported in districts bordering the DRC, Sudan, Kenya, the lake shores, Karamoja, Acholi, and Lango sub-regions. Full article

(This article belongs to the Section Animal Viruses)

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10 pages, 405 KiB

Open AccessArticle

Soluble Neuropilin-1 as a Marker for Distinguishing Bacterial and Viral Sepsis in Critically Ill Patients—A Prospective, Multicenter, Observational Study

by Fabian Perschinka, Georg Franz Lehner, Timo Mayerhöfer, Frank Hartig, Birgit Zassler, Johannes Bösch, Dietmar Fries, Romuald Bellmann and Michael Joannidis

Viruses 2025, 17(7), 997; https://doi.org/10.3390/v17070997 - 16 Jul 2025

Viewed by 359

Abstract

Sepsis causes millions of deaths each year. Rapid, targeted therapy can reduce mortality rates. Both bacterial and viral pathogens can trigger sepsis, but the utility of commonly used inflammatory markers for differentiation remains controversial. Moreover, little is known about the time courses of [...] Read more.

Sepsis causes millions of deaths each year. Rapid, targeted therapy can reduce mortality rates. Both bacterial and viral pathogens can trigger sepsis, but the utility of commonly used inflammatory markers for differentiation remains controversial. Moreover, little is known about the time courses of alternative inflammatory parameters. The aim of this prospective, two-center observational study was to investigate the differences in the course of soluble Neuropilin-1 (sNRP-1) levels between bacterial and viral sepsis over a 7-day period. To be included, adult patients had to meet the SEPSIS-3 criteria and be diagnosed with either a bacterial or viral pathogen. Immunosuppressed patients were excluded. While IL-6, PCT, and CRP levels decreased consistently over time, sNRP-1 levels remained elevated in the bacterial group throughout the entire ICU stay. PCT (p < 0.001) and CRP (p = 0.016) levels were significantly associated with the course of sNRP-1. The AUC of sNRP-1 was 0.777 for discriminating between bacterial and viral infections on day 1. sNRP-1 remained stable and significantly higher in bacterial than in viral infections. Furthermore, the AUC values for discrimination ranged from acceptable to good, depending on the day of the ICU stay. sNRP-1 may serve as a potential tool to differentiate between bacterial and viral pathogens in sepsis. Full article

(This article belongs to the Special Issue Viral Sepsis: Pathogenesis, Diagnostics and Therapeutics)

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27 pages, 31745 KiB

Open AccessArticle

Characterization of a STAT-1 Knockout Mouse Model for Machupo Virus Infection and Pathogenesis

by Stephanie R. Monticelli, Ana I. Kuehne, Russell R. Bakken, Susan R. Coyne, Kenise D. Lewis, Jo Lynne W. Raymond, Xiankun Zeng, Joshua B. Richardson, Zebulon Lapoint, Jennifer L. Williams, Christopher P. Stefan, Jeffrey R. Kugelman, Jeffrey W. Koehler and Andrew S. Herbert

Viruses 2025, 17(7), 996; https://doi.org/10.3390/v17070996 - 16 Jul 2025

Viewed by 689

Abstract

Machupo virus (MACV), a member of the Arenaviridae family and causative agent of Bolivian hemorrhagic fever, results in lethality rates of 25–35% in humans. Mice lacking the signal transducer and activator of transcription 1 (STAT-1^−/−) have previously been shown to succumb [...] Read more.

Machupo virus (MACV), a member of the Arenaviridae family and causative agent of Bolivian hemorrhagic fever, results in lethality rates of 25–35% in humans. Mice lacking the signal transducer and activator of transcription 1 (STAT-1^−/−) have previously been shown to succumb to MACV infection within 7–8 days via the intraperitoneal route. Despite these reports, we observed partial lethality in STAT-1^−/− mice following challenge with wild-type MACV. Serial sampling studies to evaluate the temporal progression of infection and pathologic changes after challenge revealed a two-phase disease course. The first phase was characterized by viral load and pathological lesions in the spleen, liver, and kidney followed by a second, lethal phase, defined by high viral titers and inflammation in the brain and spinal cord resulting in neurological manifestations and subsequent mortality. Tissue adaptation in the brains of challenged STAT-1^−/− mice resulted in a fully lethal model in STAT-1^−/− mice (mouse-adapted; maMACV). A similar two-phase disease course was observed following maMACV challenge, but more rapid dissemination of the virus to the brain and overall pathology in this region was observed. The outcome of these studies is a lethal small rodent model of MACV that recapitulates many aspects of human disease. Full article

(This article belongs to the Section Human Virology and Viral Diseases)

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17 pages, 1237 KiB

Open AccessArticle

Biological, Molecular, and Physiological Characterization of Four Soybean Mosaic Virus Isolates Present in Argentine Soybean Crops

by Mariel Maugeri, Marianela Rodríguez, Nicolas Bejerman, Irma G. Laguna and Patricia Rodríguez Pardina

Viruses 2025, 17(7), 995; https://doi.org/10.3390/v17070995 - 16 Jul 2025

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Abstract

Soybean mosaic virus (SMV) causes systemic infections in soybean plants, leading to chlorotic mosaic and significant yield losses. In Argentina, during the 1990s, three isolates were collected in Marcos Juárez (MJ), Manfredi (M), and Northwestern Argentina (NOA), along with the “Planta Vinosa” (PV) [...] Read more.

Soybean mosaic virus (SMV) causes systemic infections in soybean plants, leading to chlorotic mosaic and significant yield losses. In Argentina, during the 1990s, three isolates were collected in Marcos Juárez (MJ), Manfredi (M), and Northwestern Argentina (NOA), along with the “Planta Vinosa” (PV) isolate, which causes severe necrosis in some cultivars. These isolates were freeze-dried and stored at −70 °C for several years. They were recovered by mechanical inoculation and biologically, molecularly, and physiologically characterized for the first time. Three of the four isolates showed low genetic divergence in the P1, CI, and CP genes. Although SMV-NOA and SMV-PV had high nucleotide sequence identity, they differed in pathogenicity, seed mottling, and transmission efficiency by seeds or aphids. SMV-NOA caused early changes in photosystem II quantum efficiency (ɸPSII) and malondialdehyde (MDA) content before symptom expression (BS). After symptom development (LS), SMV-M significantly increased MDA, total soluble sugars, and starch compared to the other isolates. Thus, early changes in ɸPSII and sugars may influence late viral symptoms. Likewise, SMV-MJ induced more severe symptoms in the susceptible Davis cultivar than in Don Mario 4800. Therefore, our results demonstrate genomic, biological, and physiological differences among SMV isolates and variable interactions of SMV-MJ with two soybean cultivars. Full article

(This article belongs to the Special Issue Viral Diseases of Major Crops)

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16 pages, 2021 KiB

Open AccessArticle

The Cytoplasmic Tail of Ovine Herpesvirus 2 Glycoprotein B Affects Cell Surface Expression and Is Required for Membrane Fusion

by Colleen M. Lynch, Maria K. Herndon, McKenna A. Hull, Daniela D. Moré, Katherine N. Baker, Cristina W. Cunha and Anthony V. Nicola

Viruses 2025, 17(7), 994; https://doi.org/10.3390/v17070994 - 16 Jul 2025

Viewed by 397

Abstract

Ovine herpesvirus 2 (OvHV-2) causes the fatal veterinary disease malignant catarrhal fever (MCF). Fusion is an essential step in the host cell entry of enveloped viruses and is an important target for vaccine development. OvHV-2 cannot be propagated in vitro, so a robust [...] Read more.

Ovine herpesvirus 2 (OvHV-2) causes the fatal veterinary disease malignant catarrhal fever (MCF). Fusion is an essential step in the host cell entry of enveloped viruses and is an important target for vaccine development. OvHV-2 cannot be propagated in vitro, so a robust virus-free cell–cell membrane fusion assay is necessary to elucidate its entry mechanism. OvHV-2 cell–cell fusion requires three conserved herpesviral envelope glycoproteins: gB, gH, and gL. OvHV-2 fusion activity is detectable but low. We hypothesize that enhancing the cell surface expression of gB, which is the core herpesviral fusogen, will increase cell–cell fusion. We generated C-terminal truncation mutants of gB and determined their cell surface expression, subcellular distribution, and fusion activity. Two mutants, including one that lacked the entire cytoplasmic tail domain, failed to function in the cell–cell fusion assay, despite wild-type levels of surface expression. This suggests that the OvHV-2 gB cytoplasmic tail is critical for fusion. A gB mutant truncated at amino acid 847 showed increased surface expression and fusion relative to the wild type. This suggests that the robust fusion activity of gB847 is the result of increased surface expression. gB847 may be used in place of wild-type gB in an improved, more robust OvHV-2 fusion assay. Full article

(This article belongs to the Section Animal Viruses)

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14 pages, 317 KiB

Open AccessArticle

Barriers and Facilitators of Implementation of the Non-Hospital-Based Administration of Long-Acting Cabotegravir Plus Rilpivirine in People with HIV: Qualitative Data from the HOLA Study

by Diana Hernández-Sánchez, Juan M. Leyva-Moral, Julian Olalla, Eugènia Negredo and on behalf of the HOLA Study Group

Viruses 2025, 17(7), 993; https://doi.org/10.3390/v17070993 - 16 Jul 2025

Viewed by 411

Abstract

Long-acting (LA) antiretroviral therapies for human immunodeficiency virus (HIV), such as injectable formulations of cabotegravir and rilpivirine (CAB+RPV LA), are now available. Considering the limited data on the out-of-hospital administration of this combination, evaluating the implementation strategies needed is essential to support future [...] Read more.

Long-acting (LA) antiretroviral therapies for human immunodeficiency virus (HIV), such as injectable formulations of cabotegravir and rilpivirine (CAB+RPV LA), are now available. Considering the limited data on the out-of-hospital administration of this combination, evaluating the implementation strategies needed is essential to support future clinical efforts. To gather data on barriers and facilitators of implementation for CAB+RPV LA in alternative outpatient facilities, this study used qualitative interviews informed by the Consolidated Framework for Implementation Research (CFIR), with 13 staff participating in the HOLA study (NCT06185452). Data analysis followed qualitative descriptive methods, assisted by Atlas.ti software version 22. The study adhered to the COREQ guidelines. Findings reveal five main factors to consider for implementation: operational and infrastructure adaptations, integrated management of human and organizational resources, need for coordination and follow-up, professional attitudes and work environment, and patient experience and patients’ needs perceived by professionals. This study emphasizes the comprehensive operational and infrastructure adaptations, adequate staff training, and supportive professional environment required for the successful implementation of CAB+RPV LA, while considering patients’ needs throughout the externalization process (trial registration number: NCT06643897). Full article

(This article belongs to the Special Issue Cascade of Care for HIV, Hepatitis and Sexually Transmitted Infections)

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1 pages, 148 KiB

Open AccessRetraction

RETRACTED: Branda et al. Zoonotic Paramyxoviruses: Evolution, Ecology, and Public Health Strategies in a Changing World. Viruses 2024, 16, 1688

by Francesco Branda, Grazia Pavia, Alessandra Ciccozzi, Angela Quirino, Nadia Marascio, Giovanni Matera, Chiara Romano, Chiara Locci, Ilenia Azzena, Noemi Pascale, Daria Sanna, Marco Casu, Giancarlo Ceccarelli, Massimo Ciccozzi and Fabio Scarpa

Viruses 2025, 17(7), 992; https://doi.org/10.3390/v17070992 - 16 Jul 2025

Viewed by 371

Abstract

The journal retracts the article “Zoonotic Paramyxoviruses: Evolution, Ecology, and Public Health Strategies in a Changing World” [...] Full article

(This article belongs to the Special Issue Emerging Zoonotic Paramyxoviruses)

10 pages, 645 KiB

Open AccessArticle

Enterovirus Detection Trends Based on Respiratory Specimens from a Single Tertiary Hospital in Korea (2018–2024): A Retrospective Study Using Multiplex PCR Data

by Jeong Su Han, Sung Hun Jang, Jae-Sik Jeon and Jae Kyung Kim

Viruses 2025, 17(7), 991; https://doi.org/10.3390/v17070991 - 16 Jul 2025

Viewed by 491

Abstract

Enteroviruses (EVs) cause broad clinical manifestations, particularly in children. Certain serotypes have been implicated in respiratory infections; however, epidemiological studies analyzing EV circulation based on clinical respiratory specimens are limited in Korea. This retrospective study evaluates EV detection patterns in respiratory specimens to [...] Read more.

Enteroviruses (EVs) cause broad clinical manifestations, particularly in children. Certain serotypes have been implicated in respiratory infections; however, epidemiological studies analyzing EV circulation based on clinical respiratory specimens are limited in Korea. This retrospective study evaluates EV detection patterns in respiratory specimens to demonstrate their clinical and epidemiological significance as respiratory pathogens in Korea. Respiratory samples collected from outpatient and hospitalized patients with respiratory symptoms at Dankook University Hospital between 2018 and 2024 were analyzed. EV detection patterns were analyzed by year, season, sex, and age. EVs were detected in 303/6292 respiratory specimens. The highest and lowest positivity rates were in 2018 (8.2%) and 2020 (1.6%), likely due to non-pharmaceutical interventions during the COVID-19 pandemic. The highest positivity rates were in summer and autumn, and in children aged 2–11 years and infants aged 0–1 years. EV positivity did not differ significantly between sexes. Significant differences were identified across years, seasons, and age groups. EVs can be detected in respiratory specimens from symptomatic patients and exhibit a marked seasonal distribution and elevated positivity rates in pediatric populations. Hence, EVs may act as atypical respiratory pathogens, underscoring the need for integrated public health surveillance and seasonal prevention strategies. Full article

(This article belongs to the Special Issue An Update on Enterovirus Research, 2nd Edition)

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