Rapid Test Research Articles

A-368 Feasibility of a Five-Minute Sample-to-Answer Basic Metabolic Panel for Point-of-Care Testing on the Fluxergy Analyzer

Abstract Background Adoption of point-of-care (POC) platforms has been limited by their high cost and limited menu (e.g., molecular only). Fluxergy has developed a cost-effective multimodal POC platform capable of performing the most common clinical chemistry, immunochemistry, hematology, molecular tests in CLIA-waived settings. This method comparison study describes the performance of the Fluxergy’s feasibility stage basic metabolic panel (BMP) with contrived samples compared to the Siemen’s epoc® Blood Analysis System. Methods Fluxergy Analyzer: The Fluxergy Analyzer is a rapid and cost-effective multimodality platform that can perform lab-quality PCR, clinical chemistry, immunochemistry, and cytometry in a single instrument and if required, in a single cartridge. Fluxergy BMP: Fluxergy BMP rapidly quantifies key electrolytes (K+, Na+, Ca2+, Cl-) and metabolites (glucose, creatinine, and BUN) from whole blood in under five minutes on the Fluxergy Analyzer, utilizing the Fluxergy test cards with screen-printed electrochemical sensor. Feasibility Study: A method comparison study was conducted to assess the performance of the feasibility stage Fluxergy BMP using contrived samples generated by spiking known concentrations of K+, Na+, Ca2+, Cl-, and glucose into buffer solutions. Samples were tested in triplicate with both the Fluxergy BMP and Siemen’s epoc® Blood Analysis System at three different concentrations across the reportable range of the epoc® Blood Analysis System. Results The feasibility stage Fluxergy BMP demonstrated strong correlation across the reportable range for K+, Na+, Ca2+, Cl-, and glucose versus the epoc® Blood Analysis System (Table 1). The error percentage for all samples tested except one glucose sample (9.5 mM) was less than 10%. The coefficient of variance for all samples tested except one Ca2+ sample (0.44 mM) was less than ten percent. Conclusions This feasibility data demonstrates the Fluxergy Analyzer is well-suited to perform rapid and accurate metabolic testing from whole blood samples at the POC.

B-204 A Real-time Probe-based PCR Assay for Detection of Pneumocystis Pneumonia

Abstract Background Pneumocystis jirovecii is an atypical opportunistic fungus with lung tropism and worldwide distribution that continues to be one of the major opportunistic pathogens causing severe Pneumocystis pneumonia (PcP) in individuals with acquired immune deficiency syndrome (AIDS) and patients with immunosuppression due to other causes. Widespread prophylaxis and treatment for P. jirovecii with sulfa drugs have decreased the incidence of PcP, but concerns have been raised about the possible emergence of P. jirovecii isolates resistant to these drugs. Point mutations in this gene have been associated with prior exposure to sulfa drugs in other microorganisms, the polymorphic positions 165 and 171, which lead to an amino acid change at positions 55 (Thr55Ala) and 57 (Pro57Ser) of the polypeptide chain, respectively. Fluorescent PCR technology can detect the nucleic acid fragments of P. jirovecii in patients' serum, alveolar perfusion fluid (BALF) and tissue samples, and further identify drug-resistant mutations, which is of great significance for early clinical and accurate initiation of antifungal therapy. MycoMDx Pneumocystis Jirovecii PCR Assay is the use of PCR-fluorescence probe method, combined with other methods to achieve the auxiliary diagnosis of P. jirovecii infection and resistance to sulfonamides (Fig. 1). Methods In this study, we did a performance evaluation of the MycoMDx Pneumocystis Jirovecii PCR Assay (CE-approved), including diagnostic sensitivity and specificity, the limit of detection (LoD), precision and stability. The above PCR assay reagents were developed and produced by Dynamiker Biotechnology (Tianjin) Co., Ltd. Results The sensitivity and specificity of the PCR assay reagents were above 90%, the LoD was 1000 copies/mL, and the precision and stability were in accordance with the requirements (CV≤5%). Conclusions The MycoMDx Pneumocystis Jirovecii PCR Assay has great clinical value by providing a rapid and reliable test to aid in early diagnosis.

A-356 A hand-held microfluidic platform for rapid and sensitive identification of respiratory viruses from nasal swab samples

Abstract Background Identifying the infected individual with a fast and accurate test is essential to constrain the spread of viruses and provide the proper treatment. Antigen rapid test (ART) provides quick screening of infection for patients; however, it shows less promising in the detection of early infection and patent’s full recovery as its inferior sensitivity to the nucleic acid detection method. On the other hand, bulky and costly instrument, tedious and prolonged procedures in traditional nucleic acid testing is also unfavorable for the screening. Delta is developing a fully automated hand-held POC using molecular technology to simultaneously detect 4 targets in 20 mins. The POC can be stand-alone or linked to mobile or PC app for different application scenarios. The proprietary recipe of the lysis buffer could neutralize the inhibition in the sample with effective pathogen lysis in seconds. The microfluidic cartridge containing lyophilized reagent can be stored at room temperature. The amplification signal is detected via the optical system from the colorimetric LAMP. This study is to evaluate the performance of the POC system in detecting SARS-CoV2 (SC2), FluA and B viruses in nasal swab. In addition, the assay performance was further compared with other commercial products available. Methods The attenuated SC2 virus, FluA and B viruses were diluted with 1xTE into different concentrations. The diluted viruses were spiked into the lysis buffer in 5% v/v ratio. Nasal samples collected from donors were soaked and swirled inside the cartridges containing lysis buffer according to the manufacturers’ instructions. For commercial products without lysis buffer, direct swabs were used. The cartridges were then put into the respective devices for further testing. Results The lyophilized SC2 assay consistently detected the viruses at 1000 copies/ml (20 out of 20) in real nasal samples in the presence of Delta Lysis Buffer (containing lyophilized neutralizer). However, without Lysis buffer, there was no signal detected even in the presence of 240x LoD viruses. The whole workflow sensitivity was tested with SC2 positive samples at 1x, 4x, 10x LoD and negative samples in the nasal sample matrix on Delta hand-held system. The results were processed via embedded algorithm and displayed on device as well as on PC and mobile app respectively. Out of 79 positive samples tested, the detection rate was 100%. There was no false positive detection for 31 negative samples tested. Positive internal control indicated the valid runs. 5 major SC2 subtypes (99.8% in silico analysis of 366,707 strains), 10 FluA and 9 FluB subtypes were successfully detected. Further, Delta hand-held platform outperformed in the LoD of SC2 with 500 copies/swab comparing to the ≥50,000 copies/swab of the benchmarked commercial platforms. Conclusions The performance of the hand-held molecular detection system we developed demonstrated a rapid, sensitive, and competitive analytical performance in the respiratory panel detection. The capability of device linking to apps and clouds for data management and the extendable docking system for multiple devices to run samples simultaneously and independently, make it applicable for the infectious diseases screening in both clinical settings and for home-use.

A-349 Evaluation of i-STAT® Point of Care Blood Gas Cartridges and Competitor Blood Gas Devices Against Reference Standard for PCO2 and PO2

Abstract Background The i-STAT System provides laboratory quality results in minutes at the patient’s bedside. Accurate and rapid test results are critical for clinical decision making in the presence of blood gas disorders, including oxygenation and acid-base status, where the partial pressure oxygen (PO2) and partial pressure carbon dioxide (PCO2) are needed. The purpose of this study was to compare the analytical performance of the PO2 and PCO2 tests in the i-STAT G3+ and i-STAT CG8+ cartridges to the theoretical PO2 and PCO2 in prepared reference standards. Two other blood gas instruments, a benchtop device and a laboratory device were also compared to the reference PO2 and PCO2. Methods Venous whole blood samples were contrived using saturation tonometry with U.S. NIST (National Institute of Science and Technology) traceable gas tanks to prepare the reference standards, which were value assigned to theoretical PO2 or PCO2 levels based on the molar composition of the gas mixture used. Eleven levels spanning the reportable range of each PO2 (5 mmHg - 800 mmHg) and PCO2 (5 mmHg - 130 mmHg) were prepared and tested in duplicate on the i-STAT G3+ and i-STAT CG8+ cartridges, benchtop device, and the laboratory device. Passing-Bablok linear regression analysis was performed to evaluate the slope and correlation coefficient, comparing each blood gas device against the reference PO2 and PCO2 values. Study designs followed CLSI (Clinical and Laboratory Standards Institute) EP09C-ED3:2018, Measurement Procedure Comparison and Bias Estimation using Patient Samples, 3rd Edition. Passing-Bablok regression analysis was also performed for the i-STAT cartridges and benchtop device against the laboratory device. Results The regression analysis was performed against the reference standards. For PO2, slopes for the i-STAT cartridges ranged from 0.93 - 0.97, the slope for the benchtop device was 0.99, and the slope for the laboratory device was 0.97. Correlation coefficients for all devices were 1.00. For PCO2, slopes for the i-STAT cartridges ranged from 0.98 - 1.02, the slope for the benchtop device was 0.85, and the slope for the laboratory device was 1.01. Correlation coefficients were 1.00 for the i-STAT cartridges and laboratory device, and 0.99 for the benchtop device. The regression analysis was also performed against the laboratory device. For PO2, slopes for the i-STAT cartridges ranged from 0.96 - 1.00, and the slope for the benchtop device was 1.02. Correlation coefficients for all devices were 1.00. For PCO2, slopes for the i-STAT cartridges ranged from 0.97 - 1.01, and the slope for the benchtop device was 0.85. Correlation coefficients were 1.00 for the i-STAT cartridges and 0.99 for the benchtop device. Conclusions The study demonstrated that the i-STAT G3+ and i-STAT CG8+ cartridges used with the i-STAT System were shown to provide laboratory quality results within 2 minutes, showing good agreement to both reference standards and laboratory quality devices. For PCO2, the i-STAT System was shown to have better agreement to both theoretical reference standards and the laboratory device than the benchtop device. These studies were funded by Abbott Laboratories.

Enhancing diagnostic accuracy: Direct immunofluorescence assay as the gold standard for detecting Giardia duodenalis and Cryptosporidium spp. in canine and feline fecal samples

The enteric protozoan parasites Giardia duodenalis and Cryptosporidium spp. are common cause of diarrhea in pet dogs and cats, affecting primarily young animals. This comparative study evaluates the diagnostic performance of conventional and molecular methods for the detection of G. duodenalis and Cryptosporidium spp. infection in dogs and cats.The compared diagnostic assays included merthiolate-iodine-formalin (MIF) method, lateral flow immunochromatography rapid test (ICT) and real-time PCR; using direct immunofluorescence assay (DFA) as golden standard. The study included the analysis of 328 fecal samples from different dog (n = 225) and cat (n = 103) populations.According to DFA, the overall prevalence of G. duodenalis was 24.4% (80/328, 95% CI: 19.8–29.4), varying from 11.6% (12/103, 95% CI: 6.2–19.5) in cats to 30.2% (68/225, 95% CI: 24.3–36.7) in dogs. The overall prevalence of Cryptosporidium spp. was 4.0% (13/328, 95% CI: 2.1–6.7), varying from 2.9% (3/103, 95% CI: 0.6–8.3) in cats to 4.4% (10/225, 95% CI: 2.1–8.0) in dogs. MIF was only used for the detection of G. duodenalis, which was identified by this method in 22.7% of dogs and 7.8% of cats, respectively. DFA was the most sensitive technique for detecting G. duodenalis in samples from dogs and cats (p-value: < 0.001), followed by real-time PCR. Identification of Cryptosporidium infections was most effectively accomplished by the combination of DFA and PCR technique (p-value: < 0.001). In addition, epidemiological (sex, age, origin) and clinical (fecal consistency) variables were collected to assess their potential associations with an increased likelihood of infection by G. duodenalis and/or Cryptosporidium spp. Breeder dogs were more likely to harbor G. duodenalis infection (p-value: 0.004), whereas female cats were significantly more infected with Cryptosporidium (p-value: 0.003).In conclusion, DFA (alone or in combination with PCR) has been identified as the most accurate and cost-effective method for detecting G. duodenalis and Cryptosporidium spp. in fecal samples from pet dogs and cats. This highlights their importance in both veterinary and clinical settings for enabling prompt treatment and preventing potential transmission to humans.

B-273 Clinical Validation of a Novel Lateral Flow Assay for Rapid and Sensitive Urine Fentanyl Screening

Abstract Background The urgent need for rapid fentanyl detection at the point-of-care originates from its involvement in a high number of overdose deaths, primarily due to illicit use. Given fentanyl's potency compared to traditional opioids, accurate and sensitive detection is critical. Current lateral flow assays (LFA) cannot detect single-digit concentrations and may yield false negatives due to their lower sensitivity. Herein, we evaluate the clinical performance of a novel LFA (InstaStrip Fentanyl Rapid Test (urine)) with 1 ng/mL cutoff for fentanyl and no cross-reactivity for norfentanyl, offering enhanced sensitivity for effective overdose prevention at the ED. Methods A total of 172 urine samples submitted for UDS analysis were used for comparison studies. Fentanyl concentrations were categorized in 5 groups to cover various concentration categories around the cutoff of the LFA (1 ng/mL). These categories are: drug-free (&amp;lt;0.1 ng/mL, n=68), 0.1-0.5 ng/mL (n=14), 0.5-0.9 ng/mL (n=15), 1-1.5 ng/mL (n=9) and &amp;gt; 1.5 ng/mL (n= 66). Concentrations were determined by in-house LC-MS/MS methods validated according to CLIA standards, with fentanyl concentrations quantitated in the ABSciex software. For LFA testing, 150 μL of urine was added to a reagent tube containing dried rabbit anti-fentanyl antibody conjugated gold nanoparticles. After 20 sec of brief shaking, a test strip was inserted into the test tube. After 5 min, qualitative results were read as follow: both the control and test lines were visible in negative results, whereas only the control lines were visible in positive results. Method comparison study of the LFA was conducted by three operators who were blinded to the LC-MS/MS results. Result comparisons were made between the LFA strip and LC-MS/MS results, as well as among different operators for the same samples. Results Of the 75 urine samples with LC-MS/MS fentanyl concentrations ≥ 1 ng/mL, 74 produced consistently positive results using the InstaStrip Fentanyl Rapid Test. Of the 97 urine samples with LC-MS/MS fentanyl concentrations &amp;lt; 1 ng/mL, 96 produced consistently negative results using the InstaStrip Fentanyl Rapid Test. Using the LC-MS/MS as the gold standard method and 1 ng/mL as a cutoff, the clinical sensitivity of InstaStrip Fentanyl Rapid Test was calculated to be 98.67% (95% confidence interval (CI) 92.79-99.97%), and the clinical specificity was 98.97% (95% CI 94.39-99.97%). Consistent results among three operators were obtained for 100% of the “drug free”, “0.1- 0.5 ng/mL” and &amp;gt; 1.5 ng/mL groups, whereas 93.3 % (14 out of 15) and 88.9% (7 out of 8) were obtained for the “0.5-0.9 ng/mL” and “1-1.5 ng/mL” groups, respectively. The two samples with a singlet discrepant result (1 false positive and 1 false negative) in the triplicate experiments contained fentanyl concentrations of 0.9 and 1.0 ng/mL respectively, which are very close to the cutoff value. Conclusions In this study, the InstaStrip Fentanyl Rapid Test (urine) demonstrated high clinical sensitivity (98.67%), high specificity (98.97%) and high reproducibility showing that it may be useful in screening and identifying patients with fentanyl overdose in minutes in an emergency setting. This would facilitate appropriate patient triaging for optimal clinical care.

[Translated article] Diagnosis of Onychomycosis: Utility of an Immunochromatography Strip Test Compared with Conventional Culture

BackgroundRingworm is highly prevalent in our setting and is frequently observed in our routine clinical practice. Diagnostic confirmation depends on techniques that are not always accessible (PCR), with highly variable sensitivity depending on the observer (direct microscopy) or delayed results (culture, histopathology). Recently, an immunochromatography-based rapid test (Diafactory®) for the antigenic detection of dermatophytes has been developed. This diagnostic tool can help diagnose ringworm, allowing early initiation of treatment and fewer consultation visits. ObjectiveTo determine the sensitivity and specificity of the rapid antigen detection test compared to conventional culture. Material and methodsFor a full year, 333 nail samples were collected from patients with suspected onychomycosis. The rapid test and the conventional culture were simultaneously performed on each sample. Those with a positive antigenic test result began treatment early. The remaining patients had appointments for serial cultures and subsequent medical consultation to evaluate the results. ResultsCompared to conventional culture, the sensitivity and specificity rates of the rapid antigen detection test are 97.2% and 80.7%, respectively. ConclusionThe effectiveness of the rapid antigen detection test is similar to that of conventional culture for the detection of dermatophytes in nail samples. It is a quick and simple diagnostic technique that reduces the number of patient visits to the hospital, and allows early treatment start.

Evaluating the Diagnostic Accuracy of Rapid Malaria Tests in Pediatric Patients: A Retrospective Cohort Study.

Background Malaria remains one of the most significant public health challenges, particularly in pediatric populations in developing countries. Rapid diagnostic tests (RDTs) have been widely adopted due to their ease of use and quick results, but their diagnostic accuracy, compared to microscopy, the gold standard, remains a topic of interest. Early and accurate detection of malaria is crucial in reducing complications and mortality in children, who are especially vulnerable to delayed or inaccurate diagnoses. Objective This study aims to evaluate the diagnostic accuracy of RDTs for diagnosing Plasmodium falciparum malaria in children, using microscopy as the gold standard for comparison. Methods A retrospective cohort study was conducted in the Pediatric Department of Lady Reading Hospital Medical Teaching Institution (MTI), Peshawar, from January 1, 2023, to December 31, 2023. A total of 140 pediatric patients (aged 12 years or below) who were clinically suspected of malaria were included. Patients were excluded if they had a prior confirmed diagnosis of malaria before admission, were already receiving anti-malarial treatment, or if their guardians did not provide consent for participation. Blood samples were collected from each patient and subjected to both RDT and microscopic examination. Statistical analyses, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy, were calculated using SPSS version 24.0. Multivariate logistic regression was conducted to adjust for potential confounders such as age, gender, and parasitic load. Results Out of 140 children, 83 (58.57%) tested positive for malaria by RDT, while microscopy confirmed 80 (57.14%) positive cases. The sensitivity of RDT was 96.25% (95% CI: 89.43%-99.22%), and the specificity was 90.00% (95% CI: 79.49%-96.24%). The PPV was 92.77%, and the NPV was 94.74%, with a diagnostic accuracy of 93.57%. Multivariate logistic regression analysis indicated that parasitic load was a significant predictor of RDT accuracy, while age and gender were not. Conclusion RDT is a highly accurate diagnostic tool for detecting Plasmodium falciparum malaria in children, demonstrating high sensitivity and specificity compared to microscopy. RDTs can be effectively used in resource-limited settings, but attention should be given to parasitemia levels to ensure accurate diagnosis.

Estimates for diagnostic accuracy of rapid antigen tests for SARS-CoV-2 in systematic reviews are consistently similar despite poor methodological rigor: a methodological overview

ObjectivesTo evaluate the design, conduct, and analysis of systematic reviews on the diagnostic accuracy of rapid antigen tests for SARS-CoV-2 during the COVID-19 pandemic. Study Design and SettingWe did a methodological overview of systematic reviews on diagnostic test accuracy, exploring methodological rigor, risk of bias and potential factors of between-review variability. ResultsOf the 31 included reviews, 30 provided summary statistics for sensitivity and 29 for specificity. Summary sensitivities ranged from 56.2% to 91.1%, with a median of 71.5% (IQR 68.3%–76.6%) and a mean of 72.7% with a 7.2 SD. Reported summary specificity estimates were consistently high: median 99.5% (IQR 99%–99.9%) and a mean of 99.3% with a 0.9 SD. We found methodological shortcomings in the systematic reviews, with a majority showing critically low confidence in quality and a high risk of bias. ConclusionDespite significant methodological flaws in the reviews, the diagnostic accuracy estimates for rapid antigen tests were characterized by a strong central tendency, highlighting the importance of large sample sizes and broad participant representation. This study suggests the need for further research in diagnostic test accuracy assessments of rigor and risk of bias in systematic reviews.

Diversity of Chagas disease diagnostic antigens: Successes and limitations.

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, remains a public health issue in endemic regions of the Americas, and is becoming globalised due to migration. In the chronic phase, 2 accordant serological tests are required for diagnosis. In addition to "in-house" assays, commercial tests are available (principally ELISA and rapid diagnostic tests). Herein, we discuss the discovery era of defined T. cruzi serological antigens and their utilisation in commercialised tests. A striking feature is the re-discovery of the same antigens from independent studies, and their overlapping use among commonly reported commercial serological tests. We also consider reports of geographical variation in assay sensitivity and areas for refinement including applications to congenital diagnosis, treatment monitoring, and lineage-specific antigens.

Community-Based Delivery and Administration of Sars-CoV-2 Antigen Rapid Diagnostic Tests: An Operational Research Study in Marketplaces in Malawi and Zambia.

To expand access to testing beyond public health facilities and to strengthen surveillance efforts for COVID-19, community testing using COVID-19 antigen-based rapid diagnostic tests (Ag-RDTs) was identified as a major area of focus in Malawi and Zambia. This research aimed to gather evidence on the feasibility and acceptability of community testing in marketplaces. A cross-sectional study with a mixed-methods design was conducted in marketplaces in Malawi and Zambia to understand operational considerations for the implementation of Ag-RDTs for SARS-CoV-2 in a community setting. Programmatic data were collected prospectively as individuals were tested from June to September 2022. COVID-19 testing was done using Abbott Panbio nasal swab test kits. Semi-qualitative questionnaires were administered to individuals who tested, healthcare workers, and site-based personnel. Data were collected electronically via the SurveyCTO platform and analyzed using STATA. In Malawi, 2,348 participants were tested, and in Zambia, 1,723 people were tested for COVID-19. In Zambia, participants were 46% female, with a median age of 28 years, whereas in Malawi, participants were 69% female, with a median age of 37 years. In Malawi, 78 positive cases were reported (3.3% positivity rate), and in Zambia 10 positive cases were reported (0.5% positivity rate). In Zambia, 99% of 300 participants and in Malawi, 92% of 1,158 testers found the market testing experience and sample collection acceptable. Community testing is a feasible and acceptable intervention to increase testing access in Malawi and Zambia, especially when coupled with community awareness campaigns and mobilization.

Evaluation of a novel biplex rapid diagnostic test for antibody responses to Loa loa and Onchocerca volvulus infections.

Endemic to Central Africa, loiasis, caused by the vector-borne worm Loa loa, affects approximately 10 million individuals. Clinical manifestations include transient angioedema (Calabar swellings), migration of the adult worm under the eye conjunctiva (eye worm) and less specific general symptoms. Loiasis presents a significant public health challenge because L. loa-infected individuals can develop serious adverse events after taking ivermectin, the drug used to combat onchocerciasis. In this context, alternative interventions and rigorous diagnostic approaches are needed. Diagnosing loiasis is challenging because its main clinical manifestations are sporadic and non-specific. The definitive diagnosis relies on identifying adult worms migrating beneath the conjunctiva, or microfilariae (pre-larvae) in blood smears. However, "occult loiasis" (infection without blood microfilariae) is frequent. Serological rapid antibody diagnostic tests (ARTs) can provide an alternative diagnostic method. We compared a novel ART simultaneously targeting onchocerciasis (IgG4 to Ov-16 and OvOC3261, test line 1) and loiasis (IgG4 to L1-SXP-1, test line 2), called IgG4-SXP-1 biplex test) to the already established Loa-ART (all IgG isotypes to Ll-SXP-1, called pan-IgG-SXP-1 test). Blood samples underwent both ARTs, read qualitatively and semi-quantitatively. Additionally, blood smears, skin snips, Kato-Katz method for soil-transmitted helminthiases identification and eosinophilia measurements were performed. Questionnaires gathered demographic details and loiasis-related signs. ARTs performance was compared using specific loiasis-related signs and microfilaremia as references. Discordances between the two ARTs were investigated using logistic regression models. Out of 971 participants, 35.4% had L. loa microfilaremia, 71.9% had already experienced loiasis-related signs, 85.1% were positive in the pan-IgG-SXP-1 test and 79.4% were positive in the IgG4-SXP-1 biplex test. In the microfilariae-positive population, the sensitivity of the rapid tests was 87.4% for the pan-IgG-SXP-1 test and 88.6% for the prototype IgG4-SXP-1 biplex test. Sensitivity was similar for both ARTs when using eye worm or Calabar swelling as references, but diagnostic performance varied based on microfilaremia levels and occult loiasis. Overall, IgG4-SXP-1 biplex test demonstrated a sensitivity of 84.1% and specificity of 47.6% for loiasis compared to the pan-IgG-SXP-1 test, leading to a Kappa coefficient estimated at 0.27 ± 0.03 for the qualitative results of the 2 ARTs. In the group that tested positive with the Pan-IgG test but negative with the IgG4-specific test, there was a lower prevalence of STH infection (p = 0.008) and elevated eosinophilia (p<0.001) compared to the general tested population. The sensitivity of each test was good (84-85%) but the diagnostic agreement between the two ARTs was poor, suggesting that IgG and IgG4 antibody responses should be interpreted differently. The assessment of the innovative rapid diagnostic IgG4-SXP-1 biplex test, designed for onchocerciasis and loiasis, shows encouraging sensitivity but underlines the necessity for further in vitro assessment.

Revolution in malaria detection: unveiling current breakthroughs and tomorrow's possibilities in biomarker innovation.

The ongoing battle against malaria has seen significant advancements in diagnostic methodologies, particularly through the discovery and application of novel biomarkers. Traditional diagnostic techniques, such as microscopy and rapid diagnostic tests, have their limitations in terms of sensitivity, specificity, and the ability to detect low-level infections. Recent breakthroughs in biomarker research promise to overcome these challenges, providing more accurate, rapid, and non-invasive detection methods. These advancements are critical in enhancing early detection, guiding effective treatment, and ultimately reducing the global malaria burden. Innovative approaches in biomarker detection are leveraging cutting-edge technologies like next-generation sequencing, proteomics, and metabolomics. These techniques have led to the identification of new biomarkers that can be detected in blood, saliva, or urine, offering less invasive and more scalable options for widespread screening. For instance, the discovery of specific volatile organic compounds in the breath of infected individuals presents a revolutionary non-invasive diagnostic tool. Additionally, the integration of machine learning algorithms with biomarker data is enhancing the precision and predictive power of malaria diagnostics, making it possible to distinguish between different stages of infection and identify drug-resistant strains. Looking ahead, the future of malaria detection lies in the continued exploration of multi-biomarker panels and the development of portable, point-of-care diagnostic devices. The incorporation of smartphone-based technologies and wearable biosensors promises to bring real-time monitoring and remote diagnostics to even the most resource-limited settings.

Demographic and Clinical Features of Visceral Leishmaniasis in Chad: A Prospective Cross-Sectional Survey.

Visceral leishmaniasis (VL), caused by the protozoan Leishmania donovani complex, is endemic in many parts of the world. Little known in Chad, VL has been recently documented from previously nonendemic areas. We report an epidemiological investigation of VL in the Léré district hospital in southwestern Chad. After informed consent, 40 VL patients were enrolled in the study. Diagnosis made using the formalin serological test was confirmed by polymerase chain reaction on blood samples. Clinical parameters were obtained from the physician or nurse caregiver, and from patients. Of a total of 40 serology positive patients, L. donovani DNA was found in 33 (82.5%), with 55% being male patients. The most affected age groups were 15-29 (47.5%) and 0-14 (32.5%) years. Fever, weight loss, and pallor were frequent symptoms. Notably, splenomegaly and hepatomegaly were uncommon clinical signs. Common comorbidities included malaria (25%) and hepatitis B (15%), followed by gastric ulcer (10%) and tuberculosis (7.5%). These comorbidities were concurrent with VL and were diagnosed microscopically in blood and serum for malaria and tuberculosis, respectively, and by the rapid diagnostic test using serum for hepatitis B and gastric ulcer. Thirty-five percent of cases were treated with meglumine antimoniate, and three patients (7.5%), all with comorbidities, died. Sixty percent of patients lived close to the main town. Our data demonstrate that VL is endemic in the health district of Léré. Improving health education regarding L. donovani infection in endemic areas of Chad and providing training of health workers on early detection and management of VL are needed to help save lives.

Clinicopathological Profile in Patients with Tubercular Cervical Lymphadenitis and Its Treatment Outcome.

Tuberculosis is a common occurrence in developing countries. Drug resistance, co-morbidities, and limited availability of new rapid tests such as the GeneXpert/MTB Rif assay make diagnosis and treatment of extrapulmonary tuberculosis burdensome. A cross-sectional study was carried out at Employees' State Insurance Corporation Medical College and Hospital, Faridabad, Haryana of patients treated for tubercular cervical lymphadenopathy from December 2021 to March 2023 in the department of ENT. This study included 58 patients. The clinicopathological profile of patients and the outcome of treatment with antitubercular therapy were noted. The majority of patients had level V (39.6%) involvement. Incidental diagnosis of diabetes mellitus was seen in 2 cases (3.4%). Fever was the commonest constitutional symptom observed in 27.5% of cases. FNAC was suggestive of tubercular abscess in 48.2% and the GeneXpert MTB/RIF assay detected Mycobacterial tuberculosis in all the cases with rifampicin resistance in only one case. 56 cases (96.5%) had complete resolution after completion of antitubercular therapy including patients with rifampicin resistance and patients with diabetes mellitus. In the remaining two cases, treatment was prolonged for a few months before the resolution of the disease was observed. Timely diagnosis, patient compliance to antitubercular therapy, and adequate management of comorbidities lead to successful treatment outcomes in tubercular cervical lymphadenitis. Delayed response to treatment in a few cases needs further research into factors like immune status, nutrition, living conditions, and quality of drugs available to the public.

Lateral flow immunoassay for simultaneous detection of C. difficile, MRSA, and K. pneumoniae

Mainly performed within a rapid diagnostic tests company, a lateral flow (LF) system using gold nanoparticles (AuNPs) as transducers is presented able to detect three bacteria of interest, of relevance for antimicrobial resistance (AMR): Clostridioides difficile, methicillin-resistant Staphylococcus aureus (MRSA), and Klebsiella pneumoniae, with a limit of detection of 25 ng/mL of glutamate dehydrogenase (GDH) for C. difficile, 36 ng/mL of penicillin-binding protein 2a (PBP2a) for MRSA, and 4 × 106 CFU/mL for K. pneumoniae. The system showed good results with bacteria culture samples, is user-friendly, and suitable for rapid testing, as the results are obtained within 15 min.Graphical

A portable dual-mode colorimetric and fluorescence sensing platform for RGB detection in liquid solutions

The color of liquids is crucial in food safety, pharmaceuticals, cosmetics, and environmental monitoring. Traditional color measurement methods typically require expensive spectrophotometers, limiting their utility in rapid testing and cost-effective applications. This study developed a cost-effective, portable dual-mode colorimetric and fluorescence sensing platform with using the TCS230 sensor and STM32F103ZET6 microcontroller for real-time RGB color detection. Equipped with built-in white and ultraviolet light sources, the platform operates reliably across different environmental conditions, aided by its darkroom design and white balance calibration strategy to minimize ambient light interference. Tests with fluorescent and dye solutions show stability and reliability of the platform. The relationship between color saturation and concentration under different concentrations showed the excellent correlation coefficients above 0.99 for CuSO4 and KMnO4 solutions. The measurement deviations of 1.93% to 3.41%, render it an efficient tool for on-site and multiple-mode color testing.

Trends of coinfections among healthy blood donors: COVID-19 pandemic repercussion

ABSTRACT Background: Human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) coinfection has emerged as a leading cause of morbidity throughout the world in the last two decades. The coronavirus disease 2019 (COVID-19) pandemic has escalated the disease burden further by increasing the number of intravenous (IV) drug abusers and unemployment. Aim: The present study was done to analyse the impact of COVID-19 on seroprevalence as well as trends during pre, post and pandemic years of coinfection and mono-infections in the Malwa region of Punjab. Setting and Design: This descriptive cross-sectional study was done in the department of immunohematology and blood transfusion at a tertiary care hospital. Materials and Methods: The data on transfusion-transmitted infections (TTIs) was collected for a period of four years from 2019 to 2022, that is, pre, post and during the pandemic period. All the blood samples were screened for viral markers, HIV I and II, HCV, and hepatitis B surface antigen (HBsAg) using the enzyme-linked immunosorbent assay (ELISA) technique. Malarial antigen and syphilis infection testing was done using a rapid diagnostic card test. The total number of sero-reactive cases and their distribution were noted. Results: A total of 58,953 donors were screened and included during the study period. Each blood donor was identified by a donor registration number. The overall TTI seroprevalence in blood donors was 2.83% (n = 1670). The seroprevalence of TTIs in blood donors showed an increasing trend for HIV, HCV, and HBsAg in 2019–2021, whereas there was a decrease in reactivity status in the 2022 (back to pre-pandemic year). There was a significant increase in the coinfection rate from 0.1% to 0.25%. Conclusion: The COVID-19 pandemic impact on the coinfection rate of TTI was significant. To curb these TTIs and coinfections, education and public awareness are the key factors. India is a developing country, so transfusion medicine specialists need to work day and night to practice safe blood services.

Nosocomial cluster of patients infected with imipenemase-1-producing Enterobacter ludwigii.

Introduction. Imipenemase (IMI) enzymes are an uncommon class A carbapenemases that have been isolated from aquatic environments and, occasionally, from clinical isolates of Enterobacterales.Aim. We describe a cluster of three patients infected by IMI-1 carbapenemase-producing Enterobacter ludwigii (IMI-1-Elud) in a tertiary university hospital in Gran Canaria, Spain.Methodology. Antimicrobial susceptibility was determined using the Vitek2 AST-N355 card and antibiotic gradient strips. The modified carbapenem inactivation method (CIM) test was performed in cases where the ertapenem MIC value was higher than 0.125 mg l-1. The carbapenemase was identified by PCR and DNA microarray and later characterized by whole-genome next-generation sequencing (NGS) with Illumina.Results. Three patients presented thoracic or abdominal infections caused by IMI-1-Elud ST1677 from 14 June 2022 to 14 July 2022. All patients underwent at least one gastroscopy during their admission, and two of them were located in adjoining rooms. Isolates were resistant to carbapenems, colistin and fosfomycin but susceptible to ciprofloxacin. IMI/NMC-A carbapenemase was detected by PCR and hybridization test and confirmed by NGS as IMI-1. All patients underwent at least one gastroscopy, and two of them were in nearby rooms. Patients showed microbiological and clinical improvement following focus drainage and targeted antibiotic treatment with a fluoroquinolone.Conclusions. This study reports the first documented global outbreak of patients infected with IMI-1-Elud. The source appeared to be related to endoscopes. Contact transmission may also have played a role. A screening method such as the modified CIM test is crucial for detecting less common carbapenemases that might not be identified by rapid molecular or immunochromatographic tests, as these often do not include bla IMI genes, which could lead to the undetected dissemination of carbapenemase-producing Enterobacterales. Effective infection source control and targeted treatment are essential for achieving a favourable clinical outcome.

An investigation of scattered light integrating collector technology for rapid blood culture sensitivity testing.

Introduction. Sepsis rates are increasing, with Gram-negative organisms representing a large proportion of bloodstream infections. Rapid antibiotic administration, alongside diagnostic investigations, is required for the effective management of these patients.Gap statement. Current diagnostics take ~48 h for a final report; therefore, rapid diagnostics are required.Aim. This study investigated a novel antibiotic sensitivity method, the scattered light integrating collector (SLIC), combined with a rapid identification method using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) technology to determine if an accurate identification and susceptibility result can be provided within 4 h of a positive blood culture report.Methodology. A total of 47 blood cultures containing Gram-negative bacteria from 46 patients were processed using the MALDI-TOF Biotyper Sepsityper for identification directly from the blood and the SLIC instrument for susceptibility testing. All organisms were also tested using the current standard workflow used in the host laboratory. Categorical agreement (CA), major errors (MaEs) and very major errors (VMEs) were determined.Results. SLIC produced susceptibility results with a 71.9% CA, 30.6% MaE and 17.5% VME. The median difference in time to the final result was 44.14 (43 : 05-45 : 15) h earlier compared to the current method.Conclusion. We conclude that SLIC was unable to consistently provide sufficiently accurate antibiotic susceptibility results compared to the current standard method.