Background Dried blood spots (DBS) offer a minimally invasive, low-cost specimen type that is well suited for HIV and hepatitis C virus (HCV) serosurveillance. Although most serological assays are intended for use with serum or plasma, many assays perform reliably with DBS. In a previous evaluation, the bioMérieux VIDAS HIV Duo Quick and Anti-HCV assays showed sensitivity and specificity ≤96% when applied to DBS. In this follow-up study, we aimed to improve the DBS elution protocol and assess whether these modifications improved the analytical performance of both assays. Methods We first examined HIV and HCV seronegative DBS under varying experimental conditions (buffer composition, number of punches, and elution parameters, including temperature and agitation) to evaluate their effects on background signal. Based on these experiments, we identified that elution in PBS containing 0.05% Tween 20 and 0.5% BSA, using a single 6 mm punch, and a 24-hour incubation at ambient temperature with agitation minimised background signal. We then analysed 494 DBS specimens from the Transitions study, a cross-sectional biobehavioural survey conducted in Dnipro, Ukraine, under these conditions. Performance metrics were calculated using the Avioq HIV-1 Microelisa System and Ortho HCV v3 ELISA Test System as the reference tests. Results Both VIDAS assays demonstrated excellent performance. Sensitivity and specificity were 100% for HIV Duo Quick and 99.03% and 100%, respectively, for Anti-HCV. Positive and negative predictive values exceeded 99%, and agreement with the reference tests was nearly perfect (κ ≥ 0.99). Conclusion These results support the use of both VIDAS assays for DBS-based serosurveillance.
Monitoring the replication of human polyomaviruses (HPyV) JCPyV and BKPyV, either due to infection or re-activation, is important in patients with different immunosuppressive treatments.We evaluated whether digital polymerase chain reaction (dPCR) would be a feasible alternative to quantitative PCR (qPCR) for detection and viral load determination of JCPyV and BKPyV, simultaneously. We adapted a laboratory-designed duplex qPCR assay to QIAcuity dPCR platform and evaluated the performance of dPCR using plasmid calibrators, clinical samples, and external quality control assessment (EQA) samples.Plasmids containing JCPyV or BKPyV genomes showed excellent linear correlation between reference values and dPCR results, with a >4 log(10) dynamic range and low variation between replicates. Of 17 EQA core samples, 16 were within the consensus values by dPCR, while qPCR results deviated by at least 1 SD in 11 samples. There was a high agreement in the detection of both viruses, as well as good linear correlation between qPCR and dPCR in clinical samples. However, systemic differences in copy number estimations, presumably due to calibration imprecision in qPCR, were observed.The QIAcuity dPCR showed excellent performance in both the detection and copy number determination of JCPyV and BKPyV. The ease of use and high accuracy of quantitation makes it an attractive alternative to qPCR.
Background Respiratory syncytial virus (RSV) is an important cause of respiratory morbidity in haematopoietic cell transplant (HCT) recipients, yet comparative data across different healthcare settings remain limited. We aimed to evaluate contemporary RSV burden, real-world management variation, and clinical outcomes across three HCT centres in South Africa and the Netherlands. Methods This retrospective multicentre cohort included adults (≥18 years) with PCR-confirmed RSV infection in the HCT care pathway between January 2015 and December 2024. Observed RSV case burden was expressed as the proportion of all transplants and as detected cases per 100 person-years. RSV testing was clinician-driven rather than protocolised, and the number of transplant recipients tested for RSV was not uniformly available across centres. Results Among transplant populations comprising 1,189 HCTs, 82 PCR-confirmed RSV infections were identified (65 EMC; 9 SG; 8 WDG). Observed centre-level case proportions ranged from 4.2% to 7.7%, corresponding to 1.2-1.5 detected cases per 100 person-years. Most infections (65%) occurred within 15 months of HCT, with 43% occurring between 0 and 9 months. Respiratory viral co-infections were documented in 16-33% of cases. Hospitalisation, ICU admission, and in-hospital mortality ranged from 25-56%, 3-22%, and 3-13%, respectively. Ribavirin-based treatment was used only at EMC. Conclusion PCR-confirmed RSV infection represented a clinically relevant but modest observed case burden in these HCT populations and was associated with generally favourable short-term outcomes. Most infections occurred early after HCT, suggesting a clinically relevant period of increased vulnerability. Because testing was clinician-driven and testing denominators were unavailable, direct comparisons of incidence between centres require caution.
T helper 17 (Th17) cells have emerged as a critical yet enigmatic subset of CD4⁺ T lymphocytes in the context of viral infections. Initially recognized for their protective functions at mucosal barriers against bacterial and fungal pathogens, Th17 cells and their signature cytokine, interleukin-17 (IL-17), play a complex, virus-specific role in antiviral immunity. This review synthesizes recent advances from 2025–2026, revealing a paradigm where Th17 responses are neither uniformly protective nor purely detrimental. Instead, the outcome is dictated by the viral pathogen, the tissue microenvironment, and the interplay with other T-cell subsets. We explore the novel concept of Th17 plasticity in viral diseases, where these cells can transdifferentiate into other phenotypes, thereby shifting the immune balance. Key findings include: (i) a newly appreciated flexibility in T-cell immunity against influenza, where protection can occur independently of classical Th1 or Th17 master regulators; (ii) the detrimental role of IL-17 in severe COVID-19 and RSV pathology, driving neutrophilic inflammation; (iii) the selective depletion of gut Th17 cells by HIV as a central mechanism driving chronic inflammation and microbial translocation; (iv) the divergent Th17 polarization patterns in HBV versus HCV infection; and (v) the involvement of Th17 cells in neuroinflammation and demyelination in HSV, EBV, and HTLV-1 infections. Furthermore, we highlight the emerging role of immunometabolism as a regulator of Th17/Treg balance and the potential of therapeutic interventions targeting metabolic pathways. By providing a comprehensive overview of recent discoveries, this review aims to inform future diagnostic and therapeutic strategies that modulate Th17 responses in viral diseases.
Background Hepatitis C virus (HCV) infection remains a global health challenge. Current diagnostic algorithms typically involve sequential HCV antibody (HCV-Ab) and HCV-RNA testing, which is laborious and delays diagnosis. To streamline this process, Roche Diagnostics launched the Elecsys® HCV Duo (HCV Duo), an assay that enables simultaneous detection of HCV-Ab and HCV core antigen (HCV-Ag) from a single serum sample. Methods We analyzed a total of 1,335 serum samples and assessed the concordance of HCV-Ab results between the HCV Duo assay and the Alinity Anti-HCV assay. We also investigated HCV‑Ag detection using a separate retrospective cohort of 18 stored HCV-RNA–positive samples. In addition, we examined the concordance of HCV-Ag and HCV-RNA results in five patients treated with direct-acting antivirals over a two-month period. Results The HCV Duo demonstrated 100% (1,335/1,335) HCV-Ab concordance with the Alinity Anti-HCV assay. Among 1,335 serum samples, 1,298 were Ab negative/Ag negative, 2 were Ab negative/Ag positive, 32 were Ab positive/Ag negative, and 3 were Ab positive/Ag positive. Historical RNA review showed that the majority of Ab positive/Ag negative cases with available RNA results represented past cured infections. Notably, 13 of 18 (72%) known HCV-RNA–positive samples were also Ag positive. In patients with antiviral treatment, HCV-Ag generally became undetectable by four weeks, mirroring HCV-RNA clearance, although transient antigen positivity persisted in one patient despite undetectable HCV-RNA. Conclusion The HCV Duo provides highly reliable HCV-Ab detection and demonstrates viral load–dependent concordance between HCV-Ag and active infection. While HCV-Ag alone cannot replace HCV-RNA testing, simultaneous Ag/Ab detection may streamline diagnostic workflows and help triage patients for confirmatory RNA testing.
Cytomegalovirus (CMV), Epstein-Barr Virus (EBV) and BK Virus (BKV) infections are common with high seropositivity rates in immunocompetent individuals but when reactivated can increase morbidity and mortality in immunocompromised individuals such as transplant recipients. Monitoring viral load of these viruses plays an important role in treatment and management of transplant recipients. This study compared the clinical performance of Alinity m CMV, Alinity m EBV, and Alinity m BKV assays to other widely utlized transplant assays. Clinical plasma specimen testing comparing Alinity m CMV with cobas CMV and RealTime CMV had coefficient of correlation (r) of 0.974 and 0.991, and mean bias of 0.16 Log IU/mL and 0.14 Log IU/mL, respectively. Clinical plasma specimen testing comparing Alinity m EBV with cobas EBV and RealTime EBV had r of 0.974 and 0.956, and mean bias of 0.09 Log IU/mL and 0.47 Log IU/mL, respectively. Alinity m BKV testing of plasma and urine specimens compared with cobas BKV demonstrated r of 0.953 and 0.932, and mean bias of -0.12 Log IU/mL and -0.15 Log IU/mL, respectively. These results support the utility of the three Alinity m assays in the management of transplant recipients.Importance: CMV, EBV and BKV viruses can cause post-transplant complications. The viral load for these viruses are monitored as part of transplant recipient management. This study provides insights to the clinical performance of the Alinity m CMV, EBV, and BKV assays compared to other widely utlized transplant assays.
Background: Dengue fever, caused by the dengue virus (DENV), is a significant global health concern with >50 million cases being recorded annually worldwide. Tropical and subtropical regions bear most of the disease burden, with it being endemic in Bangladesh. To tackle this threat, comprehension of the circulating serotypes and genotypes of DENVs is essential to gain insights into the evolution, etiology, or emergence of newly imported viruses. Hence, the study aimed to identify the circulating serotypes and genotypes of DENVs among dengue-infected patients in Dhaka, Bangladesh, in 2022. Methods: A total of 234 NS1-positive patients were enrolled in the study for serotyping of DENV via multiplex PCR. Sanger sequencing of a partial Capsid Premembrane (CPrM) region was subsequently used for genotyping. Results: Among the NS1-positive patients, DENV3 was detected in 231 (98.7%) cases, while 3 (1.3%) patients were DENV2-positive. Out of 38 samples that were sequenced, Genotype-I was detected in all (36) DENV3-positive patients, and genotype-II (cosmopolitan) was detected in all (2) DENV2-positive cases. Furthermore, phylogenetic analysis of DENV3 genotype-I showed them clustering closely with other Bangladeshi strains, alongside strains from China and Myanmar. Cosmopolitan genotypes of DENV2 clustered closely to Bangladeshi cosmopolitan strains, alongside Chinese, Singaporean, and South Korean strains. Conclusions: DENV3 was predominant in Dhaka, Bangladesh in 2022, with DENV2 being in co-circulation. No other serotype was detected in this study. Consequently, a predominance of DENV2 or re-emergence of other serotypes may potentiate a larger outbreak in upcoming years, highlighting the necessity of these studies.
Background: Reactivation of BK polyomavirus (BKPyV) in kidney transplant recipients can lead to BKPyV-associated nephropathy (BKPyVAN), a major cause of allograft dysfunction. Quantitative nucleic acid amplification tests (QNATs) enable monitoring, yet inter-assay variability may complicate interpretation despite calibration to the WHO International Standard. Objective: This study compared the qualitative agreement, quantitative correlation, and agreement across predefined viral-load strata among three automated assays: Alinity m BKV, cobas BKV, and Panther Fusion BKV. Methods: Remnant EDTA plasma specimens (n = 160) from kidney transplant recipients were tested on Alinity m BKV and cobas BKV (n = 160 each) and on Panther Fusion BKV (n = 152). Pairwise analyses included qualitative agreement, Cohen's kappa, Deming regression, Bland-Altman bias and agreement across viral-load strata (<= 4 and > 4 log(10) IU/mL). Results: Overall qualitative agreement ranged from 92.1% to 96.1%, with kappa indicating substantial to near-perfect agreement. Quantitative correlations were strong (r >= 0.929), with minimal mean bias (-0.33 to -0.08 log(10) IU/mL). Agreement was higher at <= 4 log(10) IU/mL and moderate at > 4 log(10) IU/mL. Discordances clustered near assay limits of quantification. Conclusion: The three automated assays showed high qualitative agreement and closely aligned quantitative results, with minor systematic differences near the quantification limit. Because these commercial assays report IU/mL while historical guideline thresholds are in copies/mL, clinical decisions are best supported by assay-consistent longitudinal trends rather than cross-platform threshold comparisons.
Introduction/objective With the CoLab score and/or the viability polymerase chain reaction (v-PCR) test, one can determine sooner than currently possible when a COVID-19 patient can be de-isolated. The CoLab score detects host response (blood), v-PCR test intact SARS-CoV-2 particles (nasopharyngeal swab). We investigated a potential implementation of these tests in the ICU. Design/setting Based on interviews in two Dutch hospitals, a FRAM model was built to visualize the process of clinical use of both tests. MIDI questionnaire (implementation), and mini-HTA tool (effects/costs) served as research framework. Results Work processes fit well within the current care (ICU, laboratories, IT). Correct determination of blood parameters and representativeness of the swab are crucial. Optimal interdisciplinary collaboration, knowledge of benefits of timely de-isolation, and validity are relevant for implementation. De-isolation improves ICU workflow and quality of care. Expected gains are fewer days in isolation and cost savings from reduced use of disposable protective material. Healthcare staff welcomes the potential of these tests. However, constantly changing conditions due to virus mutations, emergence of other viruses, (not present at the beginning of the pandemic when the tests were validated), relatively quick changes in patient types and numbers of ICU hospitalized patients during a pandemic, impact test validity and the need for implementation. Conclusions Both tools can be implemented in the ICU with minor requirements. Timely de-isolation improves quality of care and brings cost savings. The need for implementation now is questionable. Regular validation remains a challenge due to ever-changing circumstances.
Background The human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) represent a set of intersecting global health challenges due to the fact that they all involve the same transmission routes. Co-infection with HBV and/or HCV among people living with HIV (PLHIV) has been demonstrated to be associated with accelerated liver disease progression. Methods The present study examined the clinical implications of hepatitis B virus (HBV) and hepatitis C virus (HCV) co-infection in patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) in Jiangxi, China. A total of 810 HIV-positive individuals were enrolled in the study. Serological testing via ELISA was used to detect HBsAg and anti-HCV antibodies, while HBV DNA, HCV RNA, and HIV RNA levels were measured using quantitative real-time PCR. CD4+ T cell counts were subsequently analyzed using a technique known as flow cytometry. Results The results of the study indicated that the prevalence of HBsAg and anti-HCV antibodies in PLHIV was 12.8% and 8.3%, respectively. The prevalence of anti-HCV positivity was found to be significantly higher in the 31-50 age group compared to other age groups (P < 0.0001). Injection drug use (IDU) was identified as the primary route of HIV transmission among co-infected patients, accounting for 62.7% of HCV co-infections and 6.9% of HBV co-infections. Co-infected individuals exhibited elevated aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and accelerated liver fibrosis progression in comparison to HIV-mono-infected patients evaluated using APRI and FIB-4. Antiretroviral therapy (ART) has been demonstrated to effectively reduce HIV viral load and increase CD4+ counts after a six-month treatment period. In addition, a positive correlation between HIV and HBV viral loads was observed in the ART group (r = 0.324, p = 0.008) rather than in ART-na & iuml;ve patients. Conclusion IDU is the main route for HCV infection in HIV/AIDS patients. Co-infection with HBV and/or HCV significantly promoted hepatic fibrosis, while the present ART regimens were effective for both HIV and HBV. Consequently, it is recommended to monitor the hepatic fibrosis level in PLHIV who are co-infected with HBV and (or) HCV.
Background & Aims HIV is a major global public health concern. Accurate serological testing in the clinical laboratory using high-performing, automated analyzers is critical for preventing transmission. This study evaluated the performance of the Atellica CI analyzer, utilizing the Atellica IM HIV Antigen/Antibody Combo (CHIV) assay to determine if this new analyzer's performance was reliable and comparable to existing systems. Methods Multicenter reproducibility and cross-platform (Atellica CI, Atellica IM, ADVIA Centaur XP) comparison studies were performed. Clinical concordance analysis comprised 3374 samples which were derived from: native retrospective samples and prospectively collected samples at multiple United States sites representing diverse HIV positive and presumed negative individual categories including subjects at increased risk for HIV exposure. HIV seroconversion sensitivity was assessed using 20 commercially available panels. Regression analyses were performed between analyzers using p24 antigen dilutions. Result Maximum reproducibility %CV was less than 8.8% on the Atellica CI analyzer for all samples at or above 1.00 Index. Cross-platform agreement ranged from 98.0% to 100% across all subject samples and seroconversion panels tested. Regression analyses showed strong linear relationships between the analyzers (slope ranging from 0.96 to 1.02, correlation (r) >0.999). Conclusion This is the first report on analytical and clinical performance of the Atellica IM CHIV assay on the Atellica CI analyzer. The findings demonstrate its reliability for CHIV serological testing comparable to the Atellica IM analyzer and ADVIA Centaur XP system. It enables interchangeability of Atellica analyzers in hub-and-spoke laboratory operations while supporting transition to the latest Siemens Healthineers analyzers.
Dengue fever, caused by the dengue virus (DENV), is the most prevalent viral haemorrhagic fever worldwide. Despite being primarily a non-hepatotropic virus, liver involvement occurs in up to 60–90% of DENV infections. This narrative review examines the patterns, pathophysiology, clinical implications and the management of hepatic involvement in DENV infection.Liver involvement in dengue can vary from mild subclinical elevations of transaminases to dengue-induced severe hepatitis (DISH) and even acute liver failure (ALF), which occurs in a minority but carries a high mortality rate. Patients with pre-existing liver conditions, including metabolic dysfunction-associated steatotic liver disease, alcohol-related liver disease and cirrhosis, face an increased risk of severe dengue-related hepatic complications. Pathophysiology involves direct viral hepatocyte injury, immune-mediated damage, and hypoperfusion-induced hepatic ischemia.Elevated liver enzymes, particularly Aspartate Transaminase (AST) and Alanine Transaminase (ALT), serve as early markers of disease severity and correlate with critical phase illness and plasma leakage in DENV infection. Gallbladder involvement, manifesting as wall thickening and acalculous cholecystitis, is also common. Management remains largely supportive, focusing on maintaining hydration and tissue perfusion. N-acetylcysteine shows promise in dengue-associated ALF (D-ALF), particularly when administered early, though clinical trial evidence is lacking. While liver transplantation is generally contraindicated due to bleeding risks and hemodynamic instability, rare successful cases have been reported. Further research is needed to develop targeted therapies and establish clear transplantation criteria for d-ALF.
Background: HIV-1 drug resistance monitoring traditionally relies on Sanger sequencing of targeted pol regions. Whole genome sequencing (WGS) enables the detection of mutations in all coding regions, including minority variants and resistance-associated polymorphisms outside pol, which may impact treatment with novel antiretrovirals. Objectives: To evaluate the clinical performance of a CE-IVD certified HIV-1 WGS kit (DeepChek®, ABL SA) in a routine diagnostic laboratory, and to compare its results with those obtained by a target-specific sequencing assay. Study Design: We retrospectively analyzed 20 HIV-1 RNA/DNA samples from six individuals infected with different subtypes (A1-like, B, CRF-02, G, H) and followed at Caen University Hospital between 2018 and 2022. HIV-1 WGS was performed in five overlapping fragments using the DeepChek® Whole Genome HIV-1 Genotyping kit and sequenced on an Illumina iSeq100 platform. Results were compared to previous genotypes obtained by a CE-IVD target-specific kit. Results: WGS achieved complete genome coverage for 18/20 samples, with subtype assignments consistent with patient history. The assay detected both majority (≥20%) and minority (3–20%) resistance mutations, including gp120 S375T and M434I associated with Fostemsavir resistance. Concordance with target-specific sequencing was high for pol regions, with WGS providing additional data on env and gag polymorphisms. Conclusions: HIV-1 WGS is feasible in a hospital diagnostic laboratory and provides comprehensive resistance profiling, including detection of minority variants and novel target site polymorphisms. Its implementation can enhance therapeutic decision-making in the context of evolving antiretroviral landscapes.
Background: Lymphocytic pleural effusions of unclear etiology are frequent after lung transplantation and are associated with adverse outcomes. Reactivation of human herpesviruses, in particular Epstein-Barr Virus (EBV), has been demonstrated to account for a share of unclear pleural effusions in immunocompetent and -compromised patients. Here, we assessed the detection of human herpesviruses in a large lung transplant pleural effusion cohort. Methods: A prospectively sampled cohort of 99 pleural effusions of 67 lung transplant recipients was analyzed for HSV-1, HSV-2, EBV, CMV, HHV-6 and HHV-7 by qPCR. Clinical characteristics were compared between virus-positive versus negative pleural effusions. RESULTS: EBV could be detected in 35 %, HHV-6 in 19 %, CMV in 4 % and HHV-7 in 1 % of assessed pleural effusion samples, whereas HSV-1 and HSV-2 could not be detected. Median viral load for EBV was 1500 copies/ml, for HHV-6 1300 copies/ml and for CMV 163 copies/ml. Overall, no relevant differences were found comparing the characteristics of EBV-, HHV6- and CMV-positive versus negative pleural effusions. Conclusions: Herpesviruses can be detected in low copy numbers in a share of lung transplant pleural effusions. However, they do not seem to account for the high rate of unclear lymphocytic effusions after lung transplantation.
Background Hepatitis B virus (HBV) causes major liver disease and despite widespread vaccination, HBV infection, often asymptomatic, remains a global health issue. Serological detection of HBV biomarkers, including total antibodies (IgM and IgG) to hepatitis B core antigen (HBc) is recommended as a first step for diagnosis and infection status assessment. The aim of our study was to evaluate the performance characteristics of the improved automated Atellica IM HBcT2 assay designed to detect total anti-HBc responses without a retest zone. Methods Reproducibility, clinical performance, and seroconversion studies were performed at three U.S. sites. Clinical performance testing included: 1751 prospective (pediatric, adult) specimens, representing U.S. populations across the lifespan at risk or symptomatic of HBV disease. Positive percent agreement (PPA) and negative percent agreement (NPA) for the Atellica IM HBcT2 assay were assessed against the reference Abbott ARCHITECT CORE assay. Analytical correlation was evaluated by regression analysis. Results The assay demonstrated robust reproducibility with %CV ≤10% for samples ≥0.80 Index. Qualitative agreement between methods was excellent in the population overall as well as most HBV status categories (overall PPA=98%, NPA=99%). A high quantitative agreement was observed (slope, 0.89; Pearson’s r, 0.914). Seroconversion results showed that changes in anti-HBc total concentration of Atellica IM HBcT2 closely matched those of ARCHITECT CORE. Conclusion The Atellica IM HBcT2 assay on the Atellica IM analyzer demonstrated reliable clinical performance for detecting total anti-HBc antibodies, supporting its suitability for risk or symptom-driven testing in the diagnosis of HBV infection.
BACKGROUND: Whereas COVID-19 is now in the endemic phase, maintaining robust diagnostic capabilities remains critical for ongoing surveillance and timely response to potential infection spikes. OBJECTIVE: To evaluate the performance of the updated BD Veritor™ System for SARS-CoV-2 (Veritor; Becton Dickinson and Company, BD Life Sciences—Diagnostic Solutions, San Diego, CA ) assay against a comparator, the Panther Fusion (Fusion; Hologic Inc., San Diego, CA) and regulatory performance criteria. METHODS: This prospective, clinical study enrolled 1,181 SARS-CoV-2 symptomatic individuals across 15 U.S. sites. Healthcare providers collected dual nares samples from participants ≥6 months of age and ≤7 days from symptom onset (DSO) to determine diagnostic accuracy of Veritor compared to Fusion and expected regulatory performance criteria per previously cleared SARS-CoV-2 antigen assays. RESULTS: Of 1,045 compliant and reportable specimens, Veritor had an overall positive percent agreement (PPA) of 83.4% [95% CI; 76.6, 88.6] and a negative percent agreement (NPA) of 99.7% [95% CI; 99.0, 99.9]. Performance varied by DSO, with higher PPA closer to symptom onset, and by viral load (characterized by Fusion Ct score), with lower Ct scores associated with better Veritor performance. Veritor met the regulatory (FDA 510(k)) acceptance criteria for SARS-CoV-2 antigen testing for the 0-7 DSO range. CONCLUSION: The Veritor test allows rapid and accurate detection of SARS-CoV-2 antigen testing utilizing easy-to-collect nasal swabs.
