Search Results (339)

Kaposi’s Sarcoma-associated herpesvirus (KSHV) and Epstein–Barr virus (EBV) are oncogenic gammaherpesviruses with high prevalence in sub-Saharan Africa. Both viruses are typically acquired during childhood, establishing lifelong latency. While viral reactivation into the lytic cycle has been mainly studied in adult HIV-infected populations—and more recently in the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) co-infection—the dynamics of KSHV and EBV infection in children remain poorly understood. Here, we characterize pediatric patients (n = 175; median age 4.6 years; IQR 2.0–8.3) presenting with inflammatory conditions during the COVID-19 pandemic in South Africa (from July 2020 to February 2024). Including a healthy, non-inflammatory control group, we found widespread exposure to SARS-CoV-2 (70.9% seropositivity), with 72.6% of the children being seropositive for EBV and 19.4% for KSHV. There were no significant differences in seroprevalence between children with inflammatory conditions and healthy controls for any of these viruses, although SARS-CoV-2 antibody titers were significantly higher in the inflammatory group, while EBV immune responses were lower in children presenting with inflammation. Among the KSHV-seropositive children, no active viremia was detected (as determined by the absence of viral DNA in the peripheral blood). In contrast, 34.4% of EBV-seropositive children had detectable EBV viral load, with a modestly higher proportion in the inflammatory group. However, EBV viral load levels were comparable between children diagnosed with Multisystem Inflammatory Syndrome in Children (MIS-C), Kawasaki Disease (KD), and other inflammatory conditions. Logistic regression analyses revealed that increasing age was significantly associated with higher risk of SARS-CoV-2 and EBV seropositivity, but not KSHV. Notably, the risk of EBV DNA detection in the peripheral blood decreased with age. In summary, this study suggests effective immunological control of gammaherpesvirus infections in HIV-negative paediatric patients, even in the presence of inflammatory conditions that might otherwise trigger viral reactivation. Full article

Introduction: The health care burden of chronic hepatitis B virus (CHB) infection can be reduced by appropriate workup, treatment, and monitoring. Methods: As a primary objective, we determined whether adequate initial hepatitis B virus (HBV) laboratory workup in CHB patients is associated with improved CHB complications risk. Secondary outcomes assessed included: mortality, hospitalization, emergency department, and liver specialist visits. We conducted a retrospective cohort study from 1 January 2012 to 31 December 2018. Participants were followed from 12 months post index event until outcome occurrence, death, loss of eligibility, or 31 March 2023. Health administrative data from Ontario, Canada was utilized. The study cohort included individuals with at least one positive result of either hepatitis B surface antigen, hepatitis B e antigen, or HBV DNA viral load documented during the study window. The exposure of interest was defined as adequate laboratory workup, defined as having subsequent quantitative HBV DNA, and alanine aminotransferase testing completed within 12 months of the index event. CHB-related complications were assessed using previously validated diagnostic codes. Modified Poisson regression modelling was used to estimate relative risks. Results: The study cohort consisted of 30,794 CHB patients, with a mean age 45.7 years. The majority were male (53.5%) and within the lowest two income quintiles (50.2%). In total, 68.0% underwent adequate workup. Individuals with adequate workup were more likely to be older, male, urban based, and of the highest racialized and newcomer populations quintile. The risk for CHB complications was 1.50 (95% CI 1.36–1.65) times greater among those with adequate workup. By multivariable analysis, adequate workup was associated with a lower risk of mortality (RR 0.78; 95% CI 0.69–0.87), all-cause hospitalizations (RR 0.77; 95% CI 0.74–0.80), all-cause (RR 0.77; 95% CI 0.75–0.78), and liver-related (RR 0.67; 95% CI 0.60–0.75) ED visits. Conclusions: Adequate CHB clinical workup is associated with improved patient outcomes. Our findings advocate for the comprehensive evaluation of CHB patients using key laboratory tests to optimize clinical management and improve long-term health outcomes. We identified gaps in the workup of young adults, females, and those residing in rural settings, which should be addressed to ensure equity of HBV care. Full article

Torque Teno Virus (TTV), a common and genetically diverse component of the human virome, is not linked to any known disease but reflects immune status. Its plasma viral load has shown clinical relevance in solid organ transplant recipients, correlating it with immunosuppression when present at high levels. However, the clinical significance of TTV viral load in hematopoietic stem cell transplantation (HSCT) recipients is less understood. This systematic review aims to evaluate whether plasma TTV DNA load directly correlates with the degree of T-cell immune reconstitution after HSCT, supporting its potential role as a biomarker for immune competence. The study protocol was registered in the PROSPERO International Prospective Register of Systematic Reviews (CRD420251116208) and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Twenty-one studies were included. The results showed concordant data about TTV kinetics with peak levels reaching approximately between +90 to +120 days after transplantation. Contradictory results have instead been found for the association of TTV load with immune parameters (lymphocyte counts, viral opportunistic infection, and development of acute graft versus host diseases). Even if a low-risk bias assessment was classified in most studies (67%), it was possible to identify important clinical and methodological differences between them, which might account for the different findings observed. Therefore, future larger studies with standardized protocols are needed to assess whether TTV viral load can serve as a reliable tool for guiding clinical decisions in the context of HSCT. Full article

Several studies have demonstrated that methionine supplementation in fish diets enhances immune status, inflammatory response, and resistance to bacterial infections by modulating for DNA methylation, aminopropylation, and transsulfuration pathways. However, the immunomodulatory effects of methionine in viral infections remain unexplored. This study aimed to evaluate the effect of methionine supplementation on immune modulation and resistance to the viral haemorrhagic septicaemia virus (VHSV) in rainbow trout (Oncorhynchus mykiss). Two diets were formulated and fed to juvenile rainbow trout for four weeks: a control diet (CTRL) with all nutritional requirements, including the amino acid profile required for the species, and a methionine-supplemented diet (MET), containing twice the normal requirement of DL-methionine. After feeding, fish were bath-infected with VHSV, while control fish were exposed to a virus-free bath. Samples were collected at 0 (after feeding trial), 24, 72, and 120 h post-infection for the haematological profile, humoral immune response, oxidative stress, viral load, RNAseq, and gene expression analysis. In both diets, results showed a peak in viral activity at 72 h, followed by a reduction in viral load at 120 h, indicating immune recovery. During the peak of infection, leukocytes, thrombocytes, and monocytes migrated to the infection site, while oxidative stress biomarkers (superoxide dismutase glutathione S-transferase, and glutathione redox ratio) suggested a compromised ability to manage cellular imbalance due to intense viral activity. At 120 h, immune recovery and homeostasis were observed due to an increase in the amount of nitric oxide, GSH/GSSG levels, leukocyte replacement, monocyte influx, and a reduction in the viral load. When focusing on the infection peak, gene ontology (GO) analysis showed several exclusively enriched pathways in the skin and gills of MET-fed fish, driven by the upregulation of several key genes. Genes involved in recognition/signalling, inflammatory response, and other genes with direct antiviral activity, such as TLR3, MYD88, TRAF2, NF-κB, STING, IRF3, -7, VIG1, caspases, cathepsins, and TNF, were observed. Notably, VIG1 (viperin), a key antiviral protein, was significantly upregulated in gills, confirming the modulatory role of methionine in inducing its transcription. Viperin, which harbours an S-adenosyl-L-methionine (SAM) radical domain, is directly related to methionine biosynthesis and plays a critical role in the innate immune response to VHSV infection in rainbow trout. In summary, this study suggests that dietary methionine supplementation can enhance a more robust fish immune response to viral infections, with viperin as a crucial mediator. The improved antiviral readiness observed in MET-fed fish underscores the potential of targeted nutritional adjustments to sustain fish health and welfare in aquaculture. Full article

Background and Objectives: Kidney transplant recipients (KTRs) face increased susceptibility to persistent viral infections due to prolonged immunosuppression. While high-risk human papillomavirus (HR-HPV) infection is known to be more prevalent in this population, little is known about the co-occurrence of HPV with human herpesviruses (HHVs) infection in the female genital tract. This study aimed to investigate the presence, dynamics, and potential interactions between HR-HPV and HHVs infections—including HSV-1, HSV-2, EBV, CMV, HHV-6, and HHV-7—in female KTRs during the first year after transplantation. Materials and Methods: A total of 39 female KTRs and 79 age-matched healthy controls were enrolled in the study. Cervicovaginal swabs from recipients were obtained at three time points: two weeks, six months, and one year post-transplantation. HPV DNA was screened using PCR, followed by high-risk HPV genotyping and quantitative viral load assessment using two commercial PCR kits. HHVs were detected using a multiplex PCR assay. Results: HPV DNA was detected in 98% of the KTRs at least once during follow-up, which was significantly greater than in the controls (38%). HR-HPV was identified in 46% of the recipients over the study period, with the highest viral load at one year post-transplantation. HHVs were detected in 72% of the KTRs but not in 43% of the controls (p < 0.01), with EBV and CMV being the most common. Coinfection with HR-HPV and HHVs occurred in 46% of the recipients but not in the controls. Samples containing both EBV and CMV had significantly higher HR-HPV viral loads than samples with no HHVs or with single/other HHV combinations (p < 0.01). All cervical intraepithelial neoplasia patients were found to have combined HPV and HHV infection. Conclusions: Female KTRs present a high burden of both HR-HPV and herpesviruses infections, with increased HPV viral loads. These findings suggest a potential synergistic interaction between HR-HPV and herpesviruses in the immunosuppressed setting. Full article

Background: Efficient nucleic acid extraction is essential for reliable viral load testing, yet performance can differ widely depending on the extraction system and sample type. We compared three automated platforms, QIAcube, EZ1 Advanced, and Maxwell RSC, for their ability to recover cytomegalovirus (CMV) DNA and West Nile virus (WNV) RNA from common clinical matrices. Methods: Mock specimens were prepared using whole blood, plasma, serum, and urine collected from two donors. Samples were spiked with CMV or WNV culture material and extracted in triplicate on each platform according to the manufacturers’ protocols. Viral loads were measured using ELITech ELITE MGB assays on the InGenius system. Whole blood samples were also tested after a 1:4 dilution. Matrix-specific standard curves were applied, and viral loads were compared using Wilcoxon rank-sum tests with false-discovery rate adjustment. Results: Extraction efficiency differed substantially by platform and specimen type. For CMV, QIAcube consistently produced the highest DNA recovery across all matrices, with particularly large differences in plasma and serum, where EZ1 and Maxwell RSC yielded significantly lower loads. The WNV results varied by matrix: EZ1 and QIAcube performed similarly in plasma, while Maxwell RSC achieved the highest RNA recovery in whole blood. While the QIAcube exhibited reduced WNV recovery in blood, it achieved the best performance in serum, as specified by the kit. No significant platform differences were observed for urine. Diluting whole blood reduced variability between platforms. Conclusions: Both sample matrix and extraction system strongly influence nucleic acid recovery. These results highlight the need for matrix-specific validation and standardized extraction approaches in molecular diagnostics. Full article

Background: Parvovirus B19 (B19V; Erythroparvovirus primate 1) is now the most commonly detected virus in human endomyocardial biopsies from patients with myocarditis or dilated cardiomyopathy; however, its true causal role remains uncertain. By contrast, Protoparvovirus carnivoran 1, also known as canine parvovirus type 2 (CPV-2), is an apparent cause of myocarditis in neonatal puppies, where it replicates in cardiomyocytes, induces extensive cell death, and often leaves fibrotic scars in survivors. Conclusions: This review compares B19V and CPV-2 from basic biology to clinical expression. Divergent tropism and replication kinetics produce distinct injury patterns: predominantly endothelial and microvascular dysfunction with immune-mediated damage in adult human B19V infection versus direct, age-restricted cardiomyocyte lysis in neonatal CPV-2 infection, often followed by fibrosis. Because parvoviral DNA can persist in cardiac tissue, detection alone does not prove causality. We advocate an “evidence bundle” integrating viral load by quantitative polymerase chain reaction (qPCR), detection of viral transcripts and/or proteins when feasible, spatial co-localization with histological injury, and concordant clinical markers (cardiac troponins and advanced imaging, including cardiac magnetic resonance imaging [CMR]) to support etiologic attribution and guide management in human and veterinary cardiology. Full article

Cytomegalovirus (CMV) is the most common infectious cause of congenital malformations, often presenting with atypical clinical findings. Fetal damage is most severe following primary maternal infection during the first trimester of pregnancy, with the likelihood of transmission increasing with pregnancy advancement. CMV damage may continue to intensify during the early postnatal years. In this narrative review we summarized publications from the last 30 years addressing the epidemiology, diagnosis, prevention and treatment of CMV in pregnancy, with a special emphasis on embryonic and fetal damage. Substantial progress has been made in the diagnosis and treatment of CMV infection during pregnancy, warranting a reconsideration of current clinical approaches. Assessment of viral load enables prediction of fetal infection; its reduction by maternal treatment with valacyclovir may lower both the rate and severity of transmission. Confirmed fetal infection can be diagnosed by amniocentesis and viral DNA detection. Clinical manifestations in infants may be evident at birth (cCMV) or gradually emerge during the first years. The most common fetal damage is hearing loss alongside a variety of brain lesions resulting in significant neurological deficits, including intellectual impairment. Brain involvement is diagnosed by ultrasound or magnetic resonance imaging (MRI). Pharmacological treatment with ganciclovir or valganciclovir, if initiated early after birth, can slow the progression of hearing loss and may ameliorate other neurological and neurodevelopmental deficits. As of today, there is no approved CMV vaccine for prevention. The mRNA-1647’s vaccine, currently in phase 3 clinical trial, appears promising. These advances underscore the need for screening pregnant women in the first trimester and newborn infants of mothers suspected of having CMV infection. Neurodevelopmental follow up for several years, including hearing and visual assessment, is advised in all infants positive for CMV. Infants with clinical manifestations should be offered treatment as early as possible following diagnosis of cCMV. Full article

Background: Cervical cancer remains a major global health challenge, ranking fourth among malignancies in women, with an estimated 660,000 new cases and 350,000 deaths in 2022. Despite advances in vaccination and screening, incidence and mortality remain disproportionately high in low- and middle-income countries. The disease is strongly linked to persistent infection with high-risk human papillomavirus (HPV) types, predominantly HPV 16 and 18, whose E6 and E7 oncoproteins drive cervical intraepithelial neoplasia (CIN) and invasive cancer. This review summarizes current evidence on clinically relevant biomarkers in HPV-associated CIN and cervical cancer, emphasizing their role in screening, risk stratification, and disease management. Methods: We analyzed the recent literature focusing on validated and emerging biomarkers with potential clinical applications in HPV-related cervical disease. Results: Biomarkers are essential tools for improving early detection, assessment of progression risk, and personalized management. Established markers such as p16 immunostaining, p16/Ki-67 dual staining, and HPV E6/E7 mRNA assays increase diagnostic accuracy and reduce overtreatment. Prognostic indicators, including squamous cell carcinoma antigen (SCC-Ag) and telomerase activity, provide information on tumor burden and recurrence risk. Novel approaches—such as DNA methylation panels, HPV viral load quantification, ncRNAs, and cervico-vaginal microbiota profiling—show promise in refining risk assessment and supporting non-invasive follow-up strategies. Conclusions: The integration of validated biomarkers into clinical practice facilitates more effective triage, individualized treatment decisions, and optimal use of healthcare resources. Emerging biomarkers, once validated, could further improve precision in predicting lesion outcomes, ultimately reducing the global burden of cervical cancer and improving survival. Full article

Background/Objectives: The aim of this study was to evaluate the cycle threshold (Ct) values of self-collected vaginal samples as a triage method to colposcopy for high-risk (hr) HPV-positive women. Methods: We analyzed data from GRECOSELF, a nationwide observational cross-sectional study on HPV primary cervical cancer screening in Greece. Self-collected vaginal samples were tested with the cobas^® HPV test (Roche^® Molecular Systems, Pleasanton, CA, USA). The Ct value, i.e., the number of cycles needed until DNA amplification occurs exponentially in a PCR, reflects the viral load, and it was evaluated as a triage method to colposcopy for hrHPV-positive women. Results: For CIN2 and more advanced lesions, the Ct value, as a dichotomous variable at a cut-off of 29.7, had 54.8% (95%CI: 38.7–70.2) sensitivity, 35.4% (23.9–48.2) Positive Predictive Value (PPV), 74.2% (66.8–80.8) specificity, and 86.4% (73.6–91.6) Negative Predictive Value (NPV) for HPV16/18, while for other hrHPV types, sensitivity was 26.7% (12.3–45.9), PPV 6.7% (2.9–12.8), specificity 78.8% (75.1–82.2), and NPV 95.0% (92.5–96.8). For CIN3 and more advanced lesions, the NPV for non-HPV16/18 was 97.9 (96.1–99.1). Conclusions: For self-collected vaginal samples of hrHPV-positive women, the Ct value may be used as a triage method to colposcopy. As Ct values inversely reflect the viral loads, they are lower in high-grade CIN and/or carcinoma. Full article

Occult hepatitis B virus infection (OBI), characterized by extremely low viral loads and the persistent intrahepatic presence of cccDNA, poses a profound challenge to global public health security. With a prevalence ranging from 0.06% to over 15% in different donor populations, OBI maintains a risk of transmission and can progress to hepatocellular carcinoma. Its prevention and control have long been limited by the sensitivity constraints of conventional detection methods, highlighting the urgent need for more sensitive diagnostic innovations. Emerging technologies offer distinct breakthroughs: ddPCR facilitates absolute quantification; CRISPR-Cas systems coupled with isothermal amplification enable rapid, point-of-care testing; third-generation sequencing resolves viral integration and mutations; and nanomaterials enhance the signal detection. This review synthesises advancements in OBI diagnostic technologies and provides a comparative overview of their strengths, limitations, and transfusion safety implications, as well as their potential applications in blood transfusion. Recommendations are also proposed to inform the advancement of OBI risk control in blood transfusion and to guide the development of novel diagnostic technologies, particularly relevant to regions with high HBV endemicity, such as China. Full article

Beak and feather disease virus (BFDV) is a small, icosahedral, non-enveloped virus with a circular single-stranded DNA genome, that belongs to the Circoviridae family. BFDV is globally distributed and poses a major threat to susceptible avian populations. This underscores the urgent need for rapid and reliable molecular detection methods to monitor and control the spread of the virus. Quantitative PCR assays offer several advantages, including high sensitivity, specificity, and the ability to quantify viral load. Here, we report the development and validation of a quantitative real-time PCR assay using a TaqMan probe targeting the replicase gene to detect BFDV in psittacine blood samples. The assay demonstrates high sensitivity, specificity, and suitability for routine diagnostic use with an LOD and an LOQ of 10 and 30 plasmid copies, respectively, determined using a recombinant plasmid containing a BFDV genomic fragment. The assay achieved 98.8% sensitivity and 100% specificity. The method also demonstrated strong repeatability and reproducibility, with intra- and inter-assay coefficients of variation of 4.14% and 4.44%, respectively. Both values are well below the acceptance threshold. Overall, this TaqMan-based real-time PCR assay is a reliable, sensitive, and efficient diagnostic tool for detecting BFDV in psittacine samples. Full article

Background/Objectives: Atypical cytological findings in cervical screening, such as ASC-US, ASC-H, and AGC, present a clinical challenge due to their variable risk of underlying high-grade lesions. The precise stratification of this risk is crucial for effective patient management. This study aimed to correlate Bethesda cytology categories with HPV genotyping, including viral load, and histological follow-up to improve risk prediction for cervical intraepithelial neoplasia grade 2 or worse (CIN2+). Materials and Methods: In this retrospective single-center study, we analyzed 407 patients with cytological reports of ASC-US, ASC-H, or AGC. All patients underwent HPV DNA testing with genotyping for 21 types, with viral load quantification for HPV16/18, and subsequent histological verification. Statistical analyses included non-parametric tests, correlation analysis, and multivariate logistic regression to identify independent predictors of CIN2+. Results: The prevalence of CIN2+ differed significantly among the cytological categories: 23.2% in ASC-US, 47.3% in ASC-H, and 19.5% in AGC. ASC-H and a high HPV16 viral load were identified as independent predictors of CIN2+ in the multivariate analysis. An ASC-H result increased the probability of CIN2+ by 2.5 times (aOR = 2.51; 95% CI: 1.28–4.94). For each 1 log10 increase in HPV16 viral load, the risk of CIN2+ increased by 30% (aOR = 1.30; 95% CI: 1.16–1.46). Stratification of ASC-US cases by HPV16 status revealed a dramatically higher positive predictive value (PPV) for CIN2+ in HPV16-positive patients (66%) compared to HPV16-negative patients (12.6%). The AGC category showed the strongest association with glandular pathology, including adenocarcinoma in situ. Conclusions: The combination of cytological findings and HPV16 viral load provides a powerful model for risk stratification. An ASC-H result is a strong independent risk marker, while the clinical significance of ASC-US is fundamentally determined by HPV16 status. These findings advocate for a risk-based management algorithm that integrates liquid-based cytology with extended HPV genotyping and viral load assessments to optimize patient triage and follow-up. Full article

Piscine orthoreovirus genotype 1 (PRV-1) is an emerging viral pathogen in salmon aquaculture that causes Heart and Skeletal Muscle Inflammation (HSMI), with high prevalence in salmon-producing countries such as Chile. A significant obstacle in PRV-1 vaccine development is the inability to culture the virus in vitro, which limits the scalability and production of traditional inactivated or DNA-based vaccine strategies. This study describes the development of a novel virus-like particle (VLP)-based vaccine against PRV-1. Recombinant VLP were produced by co-expressing the six structural proteins of PRV-1 (λ1, λ2, μ1, σ1, σ2, σ3) using a baculovirus-based expression system in insect cells. In addition, to enable differentiating infected from vaccinated animals (DIVA) strategies, the σ1 protein was modified by adding of a cmyc epitope tag. The results demonstrated that the native VLP vaccine (VLP6n) significantly reduced viral loads in Atlantic salmon challenged with PRV-1. Moreover, in rainbow trout, the cmyc-tagged VLP-like vaccine (VLP6c) elicited a specific antibody response against the cmyc epitope, allowing differentiation between vaccinated and naturally infected fish. Overall, this VLP-based vaccine platform represents a promising strategy for controlling PRV-1 prevalence in salmon-producing counties, supporting the implementation of serological surveillance programs. Full article

Viruses, like influenza and Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remain major causes of upper respiratory tract infections worldwide, with symptoms ranging from asymptomatic to lethal outcomes. While antivirals and vaccines have helped ameliorate disease morbidity and mortality, these infections still pose significant challenges. Probiotics, including Lactococcus lactis strain plasma (LC-Plasma), have recently shown antiviral effects by activating plasmacytoid dendritic cells (pDCs), though their detailed mechanism remains unclear. In this study, we stimulated peripheral blood mononuclear cells (PBMCs) collected from healthy participants with LC-Plasma and conducted immunological analyses to investigate the immunomodulatory mechanisms of LC-Plasma. The supernatant derived from LC-Plasma-stimulated PBMCs (LCP Sup) exhibited dose-dependent inhibition of replication in Influenza A virus subtype H1N1 (H1N1) and SARS-CoV-2. LCP Sup significantly reduced the SARS-CoV-2 viral load in Huh-7 cells. However, in the H1N1 antiviral assay using A549 cells, LCP Sup was required at a higher concentration against H1N1 in A549 cells compared with SARS-CoV-2 in Huh-7 cells. Treatment with LCP Sup significantly upregulated interferon-stimulated genes (ISG) expression, particularly MxA, in A549 cells. While MxA showed the most notable increase, other ISGs also exhibited elevated expression levels compared with the negative control. Other cytokines, chemokines, and growth factors were also induced by LC-Plasma and CpG-DNA stimulation, and the effects of LC-Plasma were much higher than those of CpG-DNA. These results provide in vitro evidence of the antiviral mechanisms of LC-Plasma via upregulation of interferon-α (IFN-α) and related ISGs for host defense against respiratory viruses. Full article