Search Results (396)

Invasive fungal respiratory infections (IFRIs) remain a major cause of morbidity and mortality among immunocompromised patients, yet diagnosis continues to be hindered by nonspecific clinical features, limited sample accessibility, and the poor sensitivity or specificity of conventional tests. Microfluidic and microelectromechanical systems (MEMS)-based biosensing platforms have emerged as promising alternatives, enabling rapid, minimally invasive, and highly specific detection of fungal pathogens and host responses. Microfluidic nucleic acid and antigen assays allow on-chip amplification and immunodetection with reduced sample volumes and turnaround times, while CRISPR-enhanced systems further improve analytical sensitivity. Parallel advances in host response profiling—including transcriptomic, proteomic, and cytokine-based signatures—have demonstrated feasibility for integration into lab-on-a-chip platforms. MEMS-based technologies extend this potential by facilitating real-time analysis of exhaled volatile organic compounds, mechanical biosensing of fungal DNA and antigens, and in situ monitoring of device-associated biofilms. Translational studies highlight potential applications across intensive care, hematology–oncology, and transplant settings, as well as in outpatient monitoring of high-risk populations. However, several challenges remain, including limited multicenter validation, matrix-related biofouling effects, and a lack of standardization in fungal biomarker panels. Future directions include AI-driven interpretation of multianalyte data, multiplexed integration of host and pathogen markers, and development of fully cartridge-based systems for near-patient deployment. Collectively, these innovations may shift fungal diagnostics toward earlier, more precise, and patient-tailored interventions, improving outcomes in vulnerable populations. Full article

Antenatal screening for Group B Streptococcus (GBS) does not always reflect intrapartum colonisation status, and rapid molecular point-of-care tests (POCT) have been developed to enable real-time detection during labour. This prospective single-centre study evaluated the performance of six molecular assays (easyNat, FlashDetect, GenDx, GenPad, iPonatic, Revogene) and one antigen-based test (TZcheck) for intrapartum GBS detection under real-world conditions. Vaginal–rectal swabs were collected at admission from 104 women at ≥ 37 weeks of gestation and tested directly without prior enrichment, using conventional intrapartum culture as the reference standard. Diagnostic performance varied substantially across platforms, with positive percent agreement ranging from 0.0% to 80.6%, while negative percent agreement was generally high, except for GenDx. Seven culture-positive samples yielded negative results across all molecular assays, while one sample was consistently positive across multiple molecular platforms despite negative culture. Exploratory observations suggest that differences in lysis procedures may contribute to variability in assay performance, although this could not be formally assessed. These findings highlight the variability of intrapartum molecular POCT under routine conditions and underscore the need for cautious clinical interpretation and local validation prior to implementation. Full article

Rapid antigen tests targeting SARS-CoV-2 nucleocapsid protein were essential for decentralised testing during the COVID-19 pandemic. Independent performance evaluations are essential to support regulatory approval and inform clinical implementation, particularly in resource-limited settings. This study presents a retrospective analytical and operational evaluation of two instrument-based fluorescent immunoassays (FIAs): the PCL COVID-19 Ag Rapid FIA and LumiraDx SARS-CoV-2 Ag Test. Analytical sensitivity was determined using recombinant nucleocapsid protein and viral cultures. Clinical performance was assessed using residual clinical specimens (n = 110) with RT-PCR as a reference, stratified by cycle threshold (Ct). Operational characteristics were assessed using a structured Likert framework. Overall sensitivity was 63% (51–73) for PCL and 95% (88–99) for LumiraDx. For Ct ≤ 25, sensitivity increased to 93% and 100%. Specificity was ≥97% for both. LumiraDx maintained sensitivity (83–94%) at Ct 25–30, whereas PCL did not detect any positives in this range. The limit of detection was 39 pM (PCL) and 0.6 pM (LumiraDx). Operational usability was high for both (90% PCL, 87% LumiraDx). LumiraDx showed higher analytical sensitivity across a broader viral load range, supporting primary diagnostic use, whereas PCL was limited to high viral loads. This evaluation provides a reproducible framework for rapid diagnostic assessment during emerging outbreaks. Full article

The diagnosis of coccidioidomycosis is often achieved serologically by the detection of antibodies against fungal antigens. While several serologic tests are available for coccidioidomycosis, all of them are performed in a laboratory setting causing delays in diagnosis and therapeutic intervention. Point-of-care testing offers the ability to provide a shorter time to result by avoiding specimen send-out, minimizing processing steps, and employing expeditious immunochemical techniques. A preliminary trial of a rapid anti-coccidioidal antibody lateral flow assay (LFA) using fingerstick blood was performed on 22 patients with coccidioidomycosis at the point of care during outpatient clinic visits. Patients were tested longitudinally over the course of one year. An LFA reader was implemented to provide an objective result by quantifying the intensity of the test line band. There was close qualitative concordance observed between positive LFA results with send-out immunodiffusion (89.5%) and complement fixation (78.4%) standard of care clinical laboratory assays. Additionally, the relationship between LFA test line density values and traditional complement fixation antibody titers was assessed. Full article

Chimeric antigen receptor (CAR) T-cell therapy is an effective treatment for hematologic malignancies. However, it is limited by high costs, risk of severe toxicities such as cytokine release syndrome and neurotoxicity, and heterogeneous patient responses. The current therapy monitoring depends largely on subjective symptom assessment, routine laboratory tests, and basic vital signs, without real-time, quantitative evaluation of CAR T-cell expansion or activation in clinical practice. This lack of timely immune monitoring hampers individualized care and contributes to increased treatment costs. To address this need, we present a proof-of-concept, label-free rapid optical imaging (ROI) biosensor with automated machine learning analysis for direct quantification of CAR T-cells from whole blood. This microfluidic platform integrates red blood cell (RBC) removal, CAR T-cell capture, and imaging-based quantification on a single chip, eliminating the need for centrifugation, staining, and operator-dependent interpretation. For validation, 50 μL whole blood samples spiked with Jurkat cells expressing CD19 CARs underwent RBC depletion by agglutination and microfiltration. The remaining blood components were then incubated on a sensor chip functionalized with recombinant CD19 protein. Captured CAR T-cells were imaged by brightfield microscopy and automatically enumerated using a machine learning algorithm trained on fluorescence-validated cells. The CD-19 cells’ capture performance was validated by flow cytometry and fluorescence imaging. The trained machine learning model validated at 88% sensitivity and 96% specificity. Buffer and whole blood calibration curves were established across clinically relevant concentrations (1–1000 cells/µL) with triple replicates. The results showed high correlation (0.975 and 0.990 R²) between the spiked concentration and the detected CAR T-cells, with a 95% certainty limit of detection (LOD) and quantification (LOQ) of 0.6 and 1.1 cells/µL for spiked buffer, and 14 and 67 cells/µL for spiked whole-blood, respectively. Full article

Determining the characteristics of hepatitis B virus (HBV) infection in the healthy population and evaluating the effectiveness of detection strategies will facilitate the optimization of hepatitis B screening strategies in the community and accelerate the elimination of HBV infection in China by the end of 2030. Hepatitis B surface antigen (HBsAg)-electrochemiluminescence immunoassays (ECLIAs), HBsAg-rapid diagnostic tests (RDTs), and HBV DNA-nucleic acid tests (NATs) were performed on serum samples from 2721 community-based healthy participants in Guangdong Province. The screening performance of the RDT and NAT and the distribution characteristics of HBsAg and HBV DNA were evaluated. The prevalence rates of HBsAg-ECLIA, HBsAg-RDT and HBV DNA-NAT in Guangdong Province were 6.10% (95% CI: 5.26~7.06), 4.96% (95% CI: 4.21~5.84) and 6.55% (95% CI: 5.64~7.49), respectively, and the prevalence rates for the three methods for individuals aged over 30 years were 11.18%, 10.92% and 12.57%, respectively. When the ECLIA was used as the gold standard, the sensitivities of the RDT, NAT and RDT and NAT in parallel were 80.7% (95% CI: 73.9~86.4), 86.7% (95% CI: 80.6~91.5) and 93.4% (95% CI: 88.5~96.6), respectively, and the sensitivity of the RDT and NAT in parallel was greater than that of the RDT alone (p < 0.001). The parallel RDT and NAT revealed an additional cost–benefit ratio (ACBR) < 1 for males and individuals aged over 30 years, which indicated that switching from the RDT screening strategy to the RDT and NAT in parallel is more cost effective. Adults aged over 30 years are the main population with hepatitis B infection in Guangdong Province, China, whose prevalence of HBsAg-ECLIA was 11.18%. Single RDT screening is prone to miss individuals with low levels of HBsAg. It is recommended to implement an RDT and NAT in parallel for individuals older than 30 years. Full article

Prostate cancer (PCa) remains one of the most prevalent urological malignancies worldwide, with early and accurate diagnosis being critical for improving patient outcomes. Traditional screening approaches, such as digital rectal examination and prostate-specific antigen (PSA) testing, have long served as frontline tools; however, their limited specificity and sensitivity contribute to high rates of false positives, unnecessary biopsies, and overtreatment. Recent UK guidelines and international consensus increasingly question the role of PSA-based population screening, advocating for risk-stratified pathways and multiparametric MRI as first-line investigations. In parallel, advances in molecular biology have identified promising cancer-specific biomarkers, such as prostate cancer antigen 3 (PCA3) and transmembrane protease serine 2 (TMPRSS2:ERG), that outperform PSAs in terms of specificity and prognostic value. These developments have catalysed innovation in biosensor technologies, enabling rapid, cost-effective, and non-invasive detection of single and multiplex biomarkers in urine and serum. Electrochemical and optical affinity-based biosensors offer transformative potential for the development of personalised point-of-care platforms and diagnostics, reducing the reliance on invasive procedures and improving clinical decision-making. The latter can be augmented with artificial intelligence (AI) tools. This review critically examines the limitations of PSAs, synthesises evidence on novel biomarkers and imaging-led strategies, and evaluates the design, performance, and translational challenges of biosensor-based assays. Furthermore, it outlines future directions, including standardisation, large-scale clinical validation, and integration of multiplex biosensors with AI for precision diagnostics. By bridging molecular insights with engineering innovations, these approaches promise to redefine PCa screening and enable accurate, patient-centred care. Full article

Background: Human cysticercosis, caused by the larval stage (cysticerci) of the pork tapeworm Taenia solium, is an important zoonotic disease. The disease is prevalent in developing countries where porcine cysticercosis is common and undercooked pork is habitually consumed. Objective: This study aimed to develop an immunochromatography-based test kit for the rapid diagnosis of human cysticercosis using low-molecular-weight antigens purified from cyst fluid of the T. solium Asian genotype to detect specific IgG antibodies in whole blood. The kit was designated as “the cysticercosis whole-blood test kit (iCys WB kit).” Methods: It was evaluated under laboratory conditions using 164 whole-blood samples, of which 21 were from confirmed cysticercosis cases. The results of the iCys WB kit, which detects anti-T. solium (cysticercus) antibodies in simulated whole blood samples, were compared with results from corresponding human serum samples. Results: When using both sample types, iCys WB kit demonstrated an accuracy of 98.8%, a sensitivity of 91.7%, a specificity of 100%, a positive likelihood ratio of 0, a negative likelihood ratio of 0.083, and an ROC area of 0.96. The agreement between results obtained from simulated whole-blood and serum samples showed perfect concordance. Conclusions: The iCys WB kit is a valuable easy-to-handle diagnostic tool and may be applicable for supporting clinical diagnosis at the point of care. Full article

Background: Rabies is a highly fatal zoonotic disease that causes approximately 59,000 human deaths worldwide each year. Current inactivated rabies vaccines require multiple doses and are associated with high costs. The full-length rabies virus glycoprotein (RVG), a membrane protein, exhibits substantial instability in its trimeric structure during recombinant expression. This instability makes it difficult to obtain high-purity, correctly folded antigens. Objectives: This study focuses on the preparation of a full-length recombinant RVG subunit vaccine candidate expressed in a glycoengineered Pichia pastoris system with mammalian-like glycosylation. Methods: The full-length RVG gene (including the transmembrane domain and cytoplasmic tail) from the Challenge Virus Standard-11 (CVS-11) strain was codon-optimized and inserted into the pPICZαA vector to construct the recombinant expression plasmid pPICZαA-RVG. The plasmid was transformed into glycoengineered Pichia pastoris X33-7 (low-mannose type) by electroporation for inducible expression. The target protein was purified by nickel affinity chromatography, anion-exchange chromatography, and Superdex-200 size-exclusion chromatography. The structural characteristics of the purified protein were analyzed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The purified antigen was formulated with the adjuvants AS03 or MF59. BALB/c mice (n = 5 per group) were immunized intramuscularly following a four-dose schedule (days 0, 7, 14, and 28). Antigen-specific IgG antibody titers were measured by ELISA, and neutralizing antibody titers were determined using the rapid fluorescent focus inhibition test (RFFIT). Results: Glycoengineered Pichia pastoris yeast strains expressing wild-type RVG (RVG-WT) or a mutant variant (RVG-M6: R84S, R199S, H270P, R279S, K300S, and R463S) were successfully constructed. The purified RVG antigen formed nanoparticles with an average particle size of approximately 75 nm. Immunized mice generated robust RVG-specific IgG responses, with titers reaching approximately 6.31 × 10⁵ for RVG-WT after the fourth immunization, compared to 3.16 × 10³ for RVG-M6 and 5.62 × 10³ for the RVG-WT-PEG control. Two weeks after the fourth immunization, RVG-WT formulated with AS03 or MF59 induced significant neutralizing antibody responses compared with the control group (p < 0.0001 and p < 0.01, respectively). The neutralizing antibody titers reached 1:79.43 in the AS03 group and 1:33.11 in the MF59 group, whereas the WT-PEG + AS03 control group showed a low titer of 1:3.72. In contrast, RVG-M6 formulated with MF59 failed to induce detectable neutralizing antibodies (1:3.02). Furthermore, RVG-WT + AS03 induced significantly higher neutralizing antibody responses than the WT-PEG + AS03 control group (p < 0.0001), and a significant difference was also observed between the RVG-WT + MF59 and RVG-M6 + MF59 groups (p < 0.01). Conclusions: The glycoengineered Pichia pastoris expression system successfully produced uniform full-length rabies virus glycoprotein nanoparticles with high purity. When formulated with the AS03 adjuvant, RVG-WT induced high-titer neutralizing antibodies in mice, suggesting a promising strategy for the development of recombinant subunit vaccines against rabies. However, this study is limited by the absence of challenge studies and validation in target animal species, which will be further investigated in future work. Full article

Background/Objectives: Group A Streptococcus (GAS) pharyngitis is a frequent cause of morbidity in pediatric populations, which requires timely identification to prevent complications such as acute rheumatic fever. Rapid antigen detection tests (RADTs) are practical alternatives to throat culture. This study evaluates the diagnostic performance of the RapidFor™ Strep A test. Methods: This prospective clinical study enrolled 389 pediatric patients aged < 18 years with symptoms suggestive of streptococcal pharyngitis. Two throat swabs were collected from each patient: one for rapid antigen testing with RapidFor™ Strep A and one for culture. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Results: Throat culture was positive in 95 of 389 patients (24.4%). The RapidFor™ Strep A test demonstrated a sensitivity of 98.95% (95% confidence interval [CI]: 94.28–99.81%) and a specificity of 96.26% (95% CI: 93.43–97.90%). The PPV was 89.52%, and the NPV was 99.65%. Agreement with culture was excellent (κ = 0.919); in particular, false-positive results accounted for 2.8% and false-negative results accounted for 1.05%. Fever was the strongest clinical indicator associated with positive results. Conclusions: The RapidFor™ Strep A test showed very high diagnostic accuracy compared with throat culture, including an excellent NPV (99.6%), which supports its reliability for ruling out GAS pharyngitis in pediatric settings. The test is an effective screening tool that facilitates timely antibiotic therapy. Full article

Hepatitis B virus (HBV) remains a major global public health challenge, and its early screening is essential for controlling transmission and improving treatment outcomes. We analyzed serum samples from 422 participants via Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to establish a screening model for hepatitis B surface antigen (HBsAg)-positive status. Following multi-bin preprocessing and single-sample spectral aggregation, we assessed three machine learning algorithms—random forest, deep neural network, and light gradient boosting machine (LightGBM). Among them, the LightGBM model achieved the best performance, with an optimized F1 score of 0.87 and an area under the receiver operating characteristic curve (AUC) of 0.94. A 100-iteration ensemble feature stabilization strategy identified twelve distinct m/z peaks as stable biomarkers for HBsAg-positive screening. Independent validation yielded sensitivity of 77.7% and specificity of 76.0%—insufficient for individual diagnosis but potentially suitable for population-level surveillance programs combined with confirmatory testing, particularly in resource-limited settings where conventional methods are impractical. Notably, the method offers a detection time of approximately one minute, a per-sample cost of ~$0.14. In conclusion, the combination of MALDI-TOF MS and machine learning enables a rapid, low-cost screening tool for large-scale HBV detection. Full article

Human immunodeficiency virus (HIV) remains a major global health challenge, requiring accurate diagnostic testing for early detection. Chemiluminescent immunoassay screening, particularly the Architect HIV Ag/Ab Combo assay, followed by immunoblot confirmation using INNO-LIA™ has traditionally been used in many diagnostic workflows. To address these limitations, the U.S. Centers for Disease Control and Prevention (CDC) recommends the use of an HIV-1/2 antibody differentiation immunoassay, such as the Geenius HIV-1/2 Supplemental Assay, as part of the confirmatory testing algorithm. This study evaluates the performance of two rapid HIV-1/2 confirmatory assays—the Multisure HIV-1/2 Confirmatory Test and the Bio-Rad Geenius HIV-1/2 Supplemental Assay—within a CDC-aligned diagnostic framework, with the aim of assessing Multisure as a potential alternative differentiation assay. A total of 224 archived serum samples were analyzed, including true positives (n = 38), true negatives (n = 139), false positives (n = 20), and INNO-LIA™ indeterminate samples (n = 27), as defined by Architect HIV and INNO-LIA™ results. Samples were initially screened using the Architect HIV Ag/Ab Combo assay, confirmed by INNO-LIA™ and PCR, and subsequently re-tested using Multisure HIV-1/2 and Geenius HIV-1/2 assays. Diagnostic performance metrics were evaluated. Both rapid assays demonstrated 100% sensitivity and specificity when compared with INNO-LIA™. Among INNO-LIA™ indeterminate samples, Multisure HIV-1/2 classified 81.5% as negative compared with 55.6% using Geenius HIV-1/2. When compared with PCR, Multisure demonstrated higher specificity (89.2%) and positive predictive value (89.5%) than Geenius (82.9% and 84.6%). No confirmed HIV-2 infections were identified in the analyzed dataset, and HIV-1 subtype information was not available for the archived samples; therefore, conclusions regarding HIV-1/2 differentiation are based primarily on assay design and antigenic targets. Multisure HIV-1/2 demonstrated strong diagnostic performance comparable to established differentiation assays and may represent a practical alternative rapid confirmatory option within CDC-aligned HIV diagnostic workflows. Further studies including larger datasets and confirmed HIV-2 infections are warranted to further validate its clinical utility. Full article

Infection with SARS-CoV-2, the virus responsible for COVID-19, is associated with cytokine storm, an excessive immune response. Interleukin-6, a multifunctional cytokine, is involved in the COVID-19 immune response. Functional polymorphisms in the interleukin-6 gene promoter, namely rs1800796, rs1800797, and rs2069845, may contribute to individual susceptibility to or severity of COVID-19. In this study, 106 healthy SARS-CoV-2-negative individuals (controls) and 106 patients with severe COVID-19 (COVID-19 group), confirmed by qPCR or rapid antigen tests, were genotyped using fluorescent probes for polymorphisms. All participants were from southern Brazil. Groups were matched for sex and body mass index, with a median age of 56–57 years. The COVID-19 group exhibited blood biomarker concentrations consistent with severe disease. No significant differences were detected in genotypic or allelic frequencies between groups, and all polymorphisms conformed to the Hardy–Weinberg equilibrium. The control group minor allelic frequencies for rs1800796 (allele C, 11.3%; 95% CI, 7–16), rs1800797 (allele A, 28.3%; 95% CI, 22–34), and rs2069845 (allele G, 36.8%; 95% CI, 30–50) were similar to those of African, American, and European populations. The polymorphisms investigated were not associated with severe COVID-19 in this cohort. Full article

Background/Objectives: Next to malaria, respiratory viruses, particularly respiratory syncytial virus (RSV), are responsible for the hospitalization and death of thousands of young children each year in sub-Saharan Africa. During peak seasons, conducting separate tests is time-consuming and distressing. This underscores the need for efficient, rapid multiplexed diagnostic tools. This study aimed to evaluate the clinical performance of a lateral flow assay (LFA) based antigen combo rapid diagnostic test (ML Ag Combo RDT, manufactured by MobiLab) that detects RSV, influenza viruses A and B (Flu A/B), and SARS-CoV-2. Methods: The Allplex panel 1 rRT-qPCR assay was used as a reference assay to evaluate the clinical performance of the LFA Ag Combo RDT in pediatric hospital settings. It was performed using 470 nasopharyngeal swab (NPS) specimens from hospitalized children under two years of age with respiratory symptoms. Results: Based on the comparative analysis of the testing results for 470 NPS, the ML Ag Combo RDT demonstrated high sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 90.06%, 98.38%, 93.67, and 97.39% for RSV, and 30%, 100%, 100%, and 95.43 for Flu A/B, respectively. Agreement with the Allplex panle1 1 rRT-qPCR was strong (κ = 0.90 for RSV) and moderate (κ = 0.45 for Flu A/B), with overall accuracies of 96.63% for RSV and 95.5 for Flu A/B. This was further supported by ROC analysis for aggregated data (RSV and, Flu A/B) with an AUC value of 0.925. As expected, in samples with high viral loads (Ct < 20), the Ag Combo RDT achieved 100% sensitivity for RSV and Flu A/B. Sensitivity declined slightly at lower viral loads (Ct > 35). Conclusions: The ML Ag Combo RDT demonstrates high specificity and diagnostic accuracy for the detection of RSV and Flu A/B in pediatric hospital settings where timely diagnosis is critical. Full article

Rift Valley fever virus (RVFV) is a re-emerging, vector-borne pathogen endemic to Africa and the Arabian Peninsula, posing an increasing threat to human and animal health. Outbreaks have severe economic and social impacts on farmers, communities, and governments. Current diagnostic methods rely on PCR and ELISA; however, rapid pen-side tests would enable faster, cost-effective monitoring and outbreak control. Here, a species- and immunoglobulin class-independent capillary flow immunodiagnostic assay (lateral flow test; LFT) for detecting RVFV-specific antibodies is described. The assay uses a double-antigen approach, coupling the RVFV nucleocapsid protein, a major viral antigen, both to carbon nanoparticles and to a nitrocellulose membrane. The method was qualified with immune sera from sheep, calves, goats, and humans and benchmarked against a newly developed double-antigen ELISA and a commercial competition ELISA. Both the LFT and double-antigen ELISA demonstrated high specificity and sensitivity. This advancement brings RVFV-specific pen-side testing significantly closer to practical implementation. Full article