Viruses-Basel最新文献

Orf virus (ORFV), a member of the Parapoxvirus genus, is commonly associated with a highly infectious skin disease primarily affecting sheep and goats, with a reported zoonotic potential. Initially identified in the 18th century, ORFV has been sporadically reported in other species, including humans. The present study analyzed the genetic variability and phylodynamic patterns of ORFV using the highly variable VIR gene, focusing on global strains from multiple hosts, including various species of ruminants and humans. A dataset of 267 ORFV strains from around the world, including sequences from the understudied island of Cuba, was used for the analyses. Results revealed greater genetic variability for ORFV than previously reported. While the virus may be defined as a generalist pathogen, capable of infecting various ruminant species and less frequently humans, signs of host-specific specialization are emerging exclusively for sheep and goats. Other ruminant species and humans may be categorized as occasional hosts, with infections likely linked to habitat overlap with sheep and goats and sporadic transmission that appears influenced by specific risk factors. In conclusion, these findings contribute to a better understanding of the transmission risks posed by ORFV, highlighting the need for further investigations into its potential to infect a broader range of hosts, particularly humans.

Novel duck reovirus encodes a new nucleus-localized protein, p18. We aimed to investigate whether the nuclear entry of p18 is dependent on viral replication, identify the cellular proteins that interact with p18, and determine the transporters involved in the nuclear import. The subcellular localization of p18 was observed by confocal microscopy. Cellular proteins interacting with p18 were identified through data-independent acquisition qualitative proteomics. The interaction between p18 and importin α was determined by confocal microscopy, co-immunoprecipitation (Co-IP) and molecular docking. We observed that p18 was localized to the nucleus in transfected cells. Importin α1, α3, α4, α5, and α7 were colocalized and co-immunoprecipitated with p18. The importin α/β1 pathway inhibitor reduced the nuclear distribution of p18. The truncated form of p18, lacking the C-terminal region, was predominantly distributed in the cytoplasm. Collectively, our research suggests that the nuclear entry of p18 is independent of viral infection, importin α is implicated in the nuclear import of p18, and the C-terminal region of p18 is crucial for nuclear localization.

Background: Human parvovirus B19 causes a broad spectrum of clinical manifestations, ranging from the classic "fifth disease" to severe presentations. Clinical presentation varies considerably across age groups. In 2023-2024, a notable increase in parvovirus B19 cases was reported across Europe. Methods: We retrospectively analyzed pediatric patients with serum serology and/or plasma PCR-confirmed parvovirus B19 infection treated at the tertiary infectious diseases center (University Hospital for Infectious Diseases, Zagreb) in 2023 (January-August). Demographic, laboratory, viral load, and clinical characteristics were assessed, with emphasis on cutaneous manifestations. Results: A total of 102 patients were included (median age 10 years; 54.9% male), of whom 7.8% required hospitalization. Rash was present in 94 (92.2%) of the patients of whom 75 had erythema infectiosum and petechiae, while the rest had a combination of both. Patients with petechial rash were significantly older (p = 0.013) and exhibited lower platelet counts (p < 0.001) compared with those with erythema. A higher proportion of anti-B19V IgM (p = 0.027) and IgG (p < 0.001) antibodies was detected in patients with erythema. Petechial rash was associated with higher viral loads (p < 0.001). In univariate analysis, the presence of anti-B19V IgG antibodies was correlated with the absence of petechial rash (OR = 0.09; p < 0.001), whereas higher viral load was associated with its presence (OR = 1.7; p < 0.001). In multivariate analysis, viral load emerged as the only predictor of petechial rash (aOR = 1.4, p = 0.042). Conclusions: Parvovirus B19 remains a self-limiting illness in healthy children, despite frequent atypical presentations. Higher viremia is associated with atypical rash morphology and suggests age-related differences in immune clearance.

Hepatitis E virus (HEV) is an important cause of acute and chronic hepatitis worldwide, transmitted primarily through waterborne exposure and zoonotic foodborne pathways. In recent years, shellfish have attracted growing attention as a potential vehicle for HEV transmission. This interest is driven by epidemiological observations linking shellfish consumption to human HEV infection and by repeated detection of HEV RNA in bivalve mollusks across multiple geographic regions. This review critically evaluates the current evidence by integrating epidemiological data, environmental and food surveillance studies, and mechanistic insights into viral accumulation in shellfish. Signals from outbreak investigations, observational studies, seroepidemiological surveys, and case reports suggest that shellfish may contribute to HEV exposure. However, these findings are largely associative, methodologically heterogeneous, and limited by the absence of explicit documentation of raw or undercooked shellfish consumption in many cases. To date, no study has recovered infectious HEV from shellfish, nor has any established molecular epidemiological linkage between shellfish-derived HEV and human infections. Mechanistic knowledge from norovirus and hepatitis A virus demonstrates that bivalves can bioaccumulate enteric viruses through filter feeding, yet HEV-specific processes governing viral binding, persistence, and infectivity within shellfish remain poorly defined. Surveillance data reveal marked geographic variation in HEV RNA detection among shellfish species and production areas. Overall, existing evidence supports shellfish as a biologically plausible but unconfirmed source of HEV exposure. Addressing key knowledge gaps-particularly through direct infectivity assessments and high-resolution molecular linkage studies-will be essential to determine the public health significance of shellfish within the broader ecology of HEV transmission.

Measles resurgence threatens elimination achievements in the Americas. We conducted a nationwide analysis of Mexico's 2025-2026 measles outbreak, integrating individual-level surveillance data from the Special Surveillance System for Febrile Exanthematous Diseases with municipal-level social determinants from eight national databases, complemented by molecular surveillance data. We analyzed 6892 confirmed cases using spatial autocorrelation (Moran's I and LISA), effective reproduction number estimation, logistic regression models for municipal case presence, and multivariable logistic regression for risk factors for complications. Cases concentrated in Chihuahua (65.2%), with 47 LISA hot-spot municipalities containing 64.4% of cases. Molecular surveillance confirmed two independent introductions: D8/MVs/Ontario.CAN/47.24 (98.1%), linked to the North American outbreak, and B3 (1.9%) in Oaxaca. Transmission followed a three-stage pattern: introduction through seasonal agricultural worker networks, amplification in undervaccinated communities, and diffusion to marginalized indigenous populations. A dual-model analysis revealed that school non-attendance among children aged 6-14 years may have mediated the effect of very high marginalization on municipal case presence (OR 1.26; p < 0.001), identifying a potentially actionable vaccination pathway. Vaccine effectiveness was 98.1%, confirming susceptible accumulation rather than vaccine failure. Wave-stratified analysis showed late outbreak phase as an independent risk factor for complications (aOR 1.68, 95% CI: 1.42-2.00), converging with an age of <1 year (aOR 3.36), indigenous status (aOR 1.89), and unvaccinated status (aOR 1.96) in the most marginalized communities. Indigenous individuals comprised 29.1% of cases but 76% of the 25 deaths. This outbreak demonstrates that national vaccination thresholds are insufficient when municipal pockets of susceptibility remain systematically underserved.

Viral hemorrhagic fevers (VHFs) are highly lethal diseases that often present non-specific, influenza-like symptoms in their early stages, making clinical recognition and differentiation from other febrile illnesses difficult. This overlap underscores the critical need for diagnostic tests that are both sensitive and specific. Point-of-care (POC) diagnostic tests are an invaluable tool for detecting and controlling the spread of pathogens that threaten public health, such as VHFs, as these require fast, accurate diagnostics to ensure biosafety and appropriate mobilization of resources during outbreaks. Current molecular and serological diagnostic tests, while efficient and effective, lack the characteristics required of a POC test (POCT) to quickly and easily respond to a VHF outbreak while maintaining a low cost. Clustered regularly interspaced short palindromic repeats (CRISPR)-based diagnostic tests have gained popularity as POCTs due to their inherent attractive qualities, including high sensitivity and specificity, adaptability, low cost, quick turnaround time, and ease of use. However, studies on the development of CRISPR-based POC diagnostic tests for VHFs are limited. This review summarizes the current CRISPR-based POCTs for VHFs, including Ebola virus (EBOV), Lassa virus (LASV), Dengue virus (DENV), and Crimean-Congo hemorrhagic fever virus (CCHF). The isothermal pre-amplification methods commonly paired with CRISPR-based tests, such as loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA), are also discussed.

Bacteriophages are promising antibacterial agents for managing acne vulgaris caused by Cutibacterium acnes, particularly given increasing antibiotic resistance. Here, we isolated and characterized two lytic Cutibacterium phages, NS-ph1 and NS-ph2, from acne lesions. Both bacteriophages exhibited a broad lytic spectrum, with a high activity against 27 C. acnes strains. Adsorption assays indicated rapid attachment and one-step growth experiments revealed latent periods of 4 h (NS-ph1) and 2 h (NS-ph2) and burst sizes of 70 and 59 PFU per infected cell, respectively. After long-term storage at room temperature, both phages retained infectivity for 3 months. Genome sequencing revealed linear dsDNA genomes of 29,490 bp (NS-ph1) and 29,189 bp (NS-ph2) with 51 and 46 predicted ORFs, respectively, and no tRNAs. No genes associated with lysogeny, toxins, or antibiotic resistance were detected. Comparative genomics placed both phages within the genus Pahexavirus. Together, these data expand the diversity of Pahexavirus and provide two well-characterized lytic candidates for further evaluation in anti-acne phage therapy.

Background: In 2022, Romania experienced a sharp increase in hepatitis A virus (HAV) infections, with evidence of predominant fecal-oral transmission through sexual contact, raising concern for an outbreak among men who have sex with men (MSM). Methods: We conducted a prospective multicenter study between 1 March 2022 and 1 March 2023 in two tertiary hospitals in Bucharest. HAV infection was defined by a compatible clinical presentation, elevated liver enzymes, and positive anti-HAV IgM serology. Clinical and laboratory characteristics were compared by transmission route and HIV status. Results: A total of 191 patients were diagnosed with HAV, including 105 MSM and 86 with foodborne transmission. All were unvaccinated. Most patients were male (82.2%), with a median age of 30 years (IQR 24-38). MSM were significantly younger and reported higher-risk sexual behaviors, including chemsex and multiple or occasional partners (p < 0.0001). Among MSM, 48 (25.1%) were living with HIV, most with preserved immune status and undetectable viral loads. Clinical manifestations were similar across groups, with jaundice being most frequent (89.5%). However, MSM exhibited more severe hepatocellular injury, reflected by higher ASAT and ALAT levels and lower prothrombin concentration, independent of HIV status. MSM were also more likely to have concomitant sexually transmitted infections, including syphilis and mpox (p < 0.001). Disease was predominantly mild, although MSM had longer hospital stays. Conclusions: The 2022 HAV surge in Romania was driven by both sexual and foodborne transmission. Targeted HAV vaccination, along with integrated sexual health services and harm-reduction strategies, is essential to prevent future outbreaks.

Influenza (flu) is a common respiratory virus with seasonal global spread. Zoonotic viruses can occasionally cross species, leading to pandemic-level spread, and for flu viruses, this is considered an "antigenic shift". The flu can be particularly severe during pregnancy due to immune system adaptations that occur during pregnancy, with prior global pandemics causing excess hospitalizations, deaths, and other complications in the mothers and the neonates. We aim to review the current literature with respect to novel avian H5N1 and the potential impact of infection with flu during pregnancy. A systematic literature search was conducted. Here we provide a rapid summary of epidemiology and understanding of viral spread, published risks of H5N1 in pregnancy, the unique physiologic, cellular, and molecular adaptations making H5N1 infection unique in pregnancy, implementation of an effective vaccine program in event of a pandemic specific to pregnant individuals, optimizing peripartum care for infected individuals, and direction for future research to direct vaccine strategy and mitigate risks in a future flu pandemic.

Background/objectives: Miller-Fisher syndrome (MFS) is a rare Guillain-Barré variant defined by ophthalmoplegia, ataxia, and areflexia. Pediatric MFS is uncommon, and infectious triggers remain underrecognized. Human herpesvirus 6 (HHV-6) is neurotropic but rarely linked to immune-mediated neuropathies. In this paper, we describe a child with MFS associated with HHV-6 detected in cerebrospinal fluid (CSF) and review reported pediatric infections related to MFS.

Methods: A 5-year-old girl presented with acute ophthalmoplegia, ataxia, and diminished reflexes. Neuroimaging, ophthalmologic tests, CSF analyses, and serologic andpolymerase chain reaction (PCR) assays were performed, including multiplex reverse transcription-PCR of cerebrospinal fluid using the BioFire^® Meningitis/Encephalitis panel. A literature search was performed on Pubmed to identify pediatric (0-18 years) MFS cases with infectious triggers. Two reviewers independently screened and summarized the literature, and a PRISMA-style flow diagram was used to transparently report the study selection process.

Results: HHV-6 DNA was detected via CSF PCR twice, while tests for other pathogens were negative. Anti-GQ1b and related antibodies were negative or borderline. The patient received intravenous immunoglobulin and corticosteroids, with full recovery after one month. Among 20 published pediatric cases (1997-2021), Campylobacter jejuni was most frequent, followed by Mycoplasma pneumoniae and influenza viruses. Anti-GQ1b IgM positivity and favorable outcomes were commonly reported, including cases managed conservatively.

Conclusions: This case raises the hypothesis that HHV-6 may represent a potential post-infectious association in pediatric MFS. The review findings indicate that pediatric MFS generally follows infection, responds well to immunotherapy, and has an excellent prognosis. Viral testing may be considered in selected, hypothesis-generating contexts in atypical or seronegative pediatric MFS presentations.