Influenza viruses cause highly contagious respiratory diseases that cause millions of deaths worldwide. Rapid detection of influenza viruses is essential for accurate diagnosis and the initiation of appropriate treatment. We developed a loop-mediated isothermal amplification and lateral flow assay (LAMP-LFA) capable of simultaneously detecting influenza A and influenza B. Primer sets for influenza A and influenza B were designed to target conserved regions of segment 7 and the nucleoprotein gene, respectively. Optimized through various primer set ratios, the assay operated at 62 °C for 30 min. For a total of 243 (85 influenza A positive, 58 influenza B positive and 100 negative) nasopharyngeal swab samples, the performance of the influenza A/B multiplex LAMP-LFA was compared with that of the commercial AllplexTM Respiratory Panel 1 assay (Seegene, Seoul, Korea). The influenza A/B multiplex LAMP-LFA demonstrated a specificity of 98% for the non-infected clinical samples, along with sensitivities of 94.1% for the influenza A clinical samples and 96.6% for the influenza B clinical samples, respectively. The influenza A/B multiplex LAMP-LFA showed high sensitivity and specificity, indicating that it is reliable for use in a low-resource environment.
Background: Cerebrospinal fluid (CSF) analysis is essential for diagnosing various disorders affecting the central nervous system (CNS). Traditionally, CSF cell count analysis is performed manually using a Neubauer chamber hemocytometer, which is labor-intensive and prone to subjective interpretation. Methods: In this study, we evaluated the analytical and clinical performance of the Microscanner C3, an automated cell counting system, for CSF analysis using artificially prepared samples and 150 clinical CSF samples. Results: The lowest detectable white blood cell (WBC) count was 3.33 cells/µL, and the lowest detectable red blood cell (RBC) count was 3.67 cells/µL. The coefficients of variation (CV%) for the Microscanner C3 were lower than those for the Neubauer chamber at all cell concentrations. The correlation coefficients (R) between the Microscanner C3 and conventional methods were high: 0.9377 for WBCs and 0.9952 for RBCs when compared with the Neubauer chamber, and 0.8782 for WBCs and 0.9759 for RBCs when compared with the flow cytometer. Additionally, the Microscanner C3 showed good agreement with both the Neubauer chamber and flow cytometer in the Passing–Bablok regression analysis and Bland–Altman analysis for WBC count at all concentrations and RBC count at concentrations of 0–1000 cells/µL. Conclusions: The Microscanner C3 proved to be more sensitive, precise, and consistent compared to the conventional hemocytometer. The new system is also compact, convenient, and cost-effective, making it a valuable option for clinical laboratories.
Counting CD4+ T lymphocytes using flow cytometry is a standard method for monitoring patients with HIV infections. Simpler and cheaper alternatives to flow cytometry are in high demand because getting access to flow cytometers is difficult or impossible in resource-limited settings. We evaluated the performance of the Microscanner Plus, a simple and automated image-based cell counter, in determining CD4 counts against a flow cytometer. CD4 count results of the Microscanner Plus and flow cytometer were compared using samples from 47 HIV-infected patients and 87 healthy individuals. All CV% for precision and reproducibility tests were less than 10%. The Microscanner Plus’s lowest detectable CD4 count was determined to be 15.27 cells/µL of whole blood samples. The correlation coefficient (R) between Microscanner Plus and flow cytometry for CD4 counting in 134 clinical samples was very high, at 0.9906 (p < 0.0001). The automated Microscanner Plus showed acceptable analytical performance for counting CD4+ T lymphocytes and may be particularly useful for monitoring HIV patients in resource-limited settings.
Background: Tuberculosis (TB) remains a significant global health challenge, necessitating rapid and reliable diagnostic solutions. Current methods such as microscopy, culture, and PCR have limitations in resource-limited settings due to high costs and infrastructure requirements. Methods: In this study, we developed the MTB/IC LAMP-MS assay, a novel molecular diagnostic platform that integrates loop-mediated isothermal amplification (LAMP) technology with microscope (MS) detection. The assay enables TB diagnosis within 40 min, from nucleic acid extraction to result, requiring minimal equipment and simple operation for rapid and accurate detection. Results: Compared to the commercial AdvanSure TB/NTM real-time PCR kit, the MTB/IC LAMP-MS assay had a lower analytical sensitivity, with a limit of detection of 103 CFU/mL versus 102 CFU/mL for the commercial PCR kit, but showed a sensitivity of 93.3% and specificity of 100% in clinical tests. Additionally, the assay demonstrated minimal cross-reactivity with other respiratory pathogens, underscoring its robust specificity. In addition, the preloaded microchips demonstrated stable performance for up to 12 weeks at room temperature, supporting their field applicability. Conclusions: With its lower cost, simplified operation, and minimal infrastructure requirements, the MTB/IC LAMP-MS assay provides a practical and efficient solution for TB diagnosis in resource-limited settings.
The coronavirus disease 2019 pandemic has further complicated the epidemiology of respiratory tract infections by altering the circulation patterns of respiratory viruses and exacerbating diagnostic challenges. This study aimed to compare respiratory pathogen profiles between pediatric and adult populations during a period of increased respiratory pathogen activity in 2024, with a focus on co-detection patterns and pathogen identification. We analyzed data from 618 patients who visited Korea University Guro Hospital with acute respiratory symptoms between August and September 2024. Specimens were tested using multiplex polymerase chain reaction assays targeting both viral and bacterial pathogens. Demographic data were extracted from electronic medical records, and statistical analyses were performed to compare the pathogen profiles and co-detection rates between pediatric and adult groups. A total of 245 pediatric patients and 373 adult patients were included. Enterovirus/rhinovirus was the most common finding in pediatric patients (21.0%), whereas severe acute respiratory syndrome coronavirus 2 was most frequently detected in adults (32.9%). Co-detection of multiple pathogens was observed in 35 adult and 39 pediatric cases. In pediatric patients, co-detection of Mycoplasma pneumoniae and enterovirus/rhinovirus was observed in 5.7% of cases. The prevalence of M pneumoniae was higher in the pediatric cohort, with a male predominance. Severe acute respiratory syndrome coronavirus 2 was detected in 60 adult cases and 7 pediatric cases. These findings highlight notable age-related differences in the pathogen profiles of acute respiratory infections. This study provides epidemiological data regarding respiratory pathogen detection and co-detection patterns across age groups.