Rapid Antigen Detection Research Articles

Diagnostic Accuracy of a Rapid Antigen Detection Test for Group A Streptococcus in Children With Pleural Empyema.

Diagnostic Accuracy of a Rapid Antigen Detection Test for Group A Streptococcus in Children With Pleural Empyema.

Molecular Diagnostics for Group A Streptococcal Pharyngitis: Clinical and Economic Benefits in the Belgian Healthcare Context

(1) Background: Group A Streptococcal (GAS) pharyngitis is common, resulting in numerous ambulatory visits. Accurate diagnosis is challenging. This study evaluated the clinical utility, cost, and performance of a nucleic acid amplification test (NAAT) for GAS detection, comparing it to a rapid antigen detection test (RADT) and throat culture. Additionally, we assessed the diagnostic stewardship related to these testing methods to ensure appropriate antibiotic use in clinical practice. Methods: Between November 2022 and February 2023, 82 throat swabs were analyzed, with McIsaac clinical scores calculated for each. The Abbott ID NOW STREP A 2 NAAT and Sekisui Diagnostics’ OSOM® STREP A RADT were performed, followed by bacterial culture. Diagnostic performance was compared using culture as the gold standard. Results: Of the 82 samples, 28 (34.14%) tested positive for pathogenic germs, primarily Streptococcus pyogenes (92.85%). RADTs showed a sensitivity of 80.76% and a specificity of 100%, while NAATs demonstrated a sensitivity of 100% and specificity of 96.42%. Cost analysis indicated the need for reimbursement adjustments to optimize NAAT’s economic benefits. Clinical data indicated that symptoms alone were insufficient for reliable diagnosis. Conclusions: This study confirmed the superior sensitivity of Abbott’s Strep A2 NAAT over RADT. Given the Belgian guidelines against routine antibiotic treatment for pharyngitis and considering local treatment recommendations and cost, implementing NAAT for GAS detection in Belgian laboratories is less beneficial. However, the role of NAAT in supporting antimicrobial stewardship by ensuring appropriate antibiotic use remains significant.

Use of point-of-care tests in pharyngotonsillitis – a registry-based study in primary health care

Background Point-of-care (POC) tests, including C-reactive protein (CRP) tests and rapid antigen detection tests (RADT) for group A streptococci (GAS), are widely used in Swedish primary health care (PHC). This study quantifies their use in pharyngotonsillitis and explore their association with antibiotic prescribing. Material and methods Retrospective data from 2012–2016 in Region Kronoberg, Sweden, included all PHC visits with a pharyngotonsillitis diagnosis. Patient characteristics, test usage and antibiotic prescriptions were linked by visit date and personal identification number. Descriptive statistics were used for POC test analysis. Logistic regression assessed the association between CRP levels and antibiotic prescribing. Results Of 24,237 visits, 68% included RADT and 36% included a CRP test, with 89% of CRP tests performed alongside RADT. CRP testing was more frequent in patients with negative (56%) than positive RADTs (42%) (p < .001). Overall, 66% of RADTs were positive. Median CRP levels were 23 mg/l for positive RADT and 31 mg/l for negative RADT (p < .001). Antibiotics were prescribed for 95% of positive RADTs and 43% of negative RADTs (p < .001). In patients with negative RADTs, CRP testing was associated with higher antibiotic prescribing (57%) compared to no CRP testing (26%) (p < .001). Among these patients, CRP levels were associated with prescribing (aOR 1.032; 95% CI 1.029–1.035; p < .001), with 50% of prescriptions occuring at CRP levels ≤ 20 mg/l. Conclusion The use of RADTs and the proportion of positive test were higher than expected, indicating inappropriate use and diagnostic bias. CRP testing, contrary to guidelines, was common and associated with increased antibiotic prescribing.

Rapid antigen detection test for diagnosis of post kala-azar dermal leishmaniasis: application of CL Detect™ rapid test for active case detection in the endemic area.

Post-kala-azar dermal leishmaniasis (PKDL) is a skin condition that occurs in a small percentage of people who have been cured of visceral leishmaniasis (VL), and contributes to transmission of VL. The rK39 rapid test cannot decisively diagnose PKDL due to presence of antileishmanial antibodies from past VL episodes. CL Detect™ Rapid Test, an in-vitro diagnostic test that detects Leishmania antigen peroxidoxin, was assessed for diagnosing PKDL. The CL Detect RDT had 73.3% sensitivity and 100% specificity in the study. The test can be used as a primary screening tool to monitor PKDL in endemic regions and identify active Leishmania infection.

[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.

Capture of Group A Streptococcus by Open-Microfluidic CandyCollect Device in Pediatric Patients.

Obtaining high-quality samples to diagnose streptococcal pharyngitis in pediatric patients is challenging due to discomfort associated with traditional pharyngeal swabs. This may cause reluctance to go to the clinic, inaccurate diagnosis, or inappropriate treatment for children with sore throat. Here, we determined the efficacy of CandyCollect, a lollipop-inspired open-microfluidic pathogen collection device, to capture Group A Streptococcus (GAS) and compare user preference for CandyCollect, conventional pharyngeal swabs, or mouth swabs in children with pharyngitis and their caregivers. All child participants (30/30) were positive for GAS by qPCR on both the mouth swab and CandyCollect. Caregivers ranked CandyCollect as a good sampling method overall (27/30), and all caregivers (30/30) would recommend CandyCollect for children 5 years and older. Twenty-three of 30 children "really like" the taste and 24/30 would prefer to use CandyCollect if a future test were needed. All caregivers (30/30) and most children (28/30) would be willing to use CandyCollect at home. All participants tested positive for GAS on all three collection methods (pharyngeal swab, mouth swab, and CandyCollect). While both caregivers and children like CandyCollect, some caregivers would prefer a shorter collection time. Future work includes additional studies with larger cohorts presenting with pharyngitis of unknown etiology and shortening collection time while maintaining the attractive form of the device. Obtaining oral samples for the diagnosis of streptococcal pharyngitis is of great importance for children. To address the challenges associated with traditional pharyngeal swab sampling, we developed the CandyCollect device, a lollipop-inspired open mesofluidic saliva sampling system. In this study, saliva samples were collected from children, aged 5-14 years, with CandyCollect and mouth swabs and analyzed via qPCR. The results show CandyCollect is the child preferred collection tool and had 100% concordance with the results from traditional diagnosis methods as part of their clinical care.

Group A Streptococcus infections in children and adolescents in the post-COVID-19 era: a regional Italian survey

BackgroundDespite the worldwide increasing incidence of Group A Streptococcus (GAS) infections reported since December 2022, data on noninvasive GAS (nGAS) infections in the post COVID-19 era are limited. By a self-reported survey performed in an outpatient setting, we investigated the number and clinical features of GAS infections, the diagnostic work-up and the type of treatment utilized. In addition, the rate of influenza vaccination was evaluated.MethodsIn June 2023 family pediatricians involved in the study sent the survey to parents of patients aged 0–16 years. The survey included questions on GAS infections that occurred from January 1 to May 31, 2023.ResultsAmong 3580 children, 20.3% had a GAS infection (0,8% < 1 year, 16,4% 1–3 years, 42,3% 3–6 years, 26,5% 6–9 years, 11,4%, 9–12 years, and 2,6% 12–16 years). Symptoms reported were sore throat (76.9%), fever (75.2%), tonsillar exudate (25.2%), lymphadenopathy (21.8%), and scarlet fever (14.7%). A single patient was hospitalized due to GAS meningitis.Twenty four percent of children had more than one GAS infection. In this group, frequencies of symptoms reported in the first and in the following infection were similar, except for fever and scarlet fever which were less frequent during relapses. GAS was identified by rapid antigen detection test in 81.0% of children. Eighty-nine per cent of children were treated with antibiotics, mostly amoxicillin/clavulanate (40.4%) and amoxicillin (39.4%). Thirty four percent of children received influenza vaccine. No difference was observed among immunized and not immunized regarding the number and characteristics of GAS infection. ConclusionsWe reported a certain prevalence of nGAS infections in children, mainly those aged 3–6 years age, who were mostly characterized by a low score of symptoms, and in most of the cases diagnosed and treated using a microbiological test as confirmatory tool.In this new clinical setting, a national study would be useful to reach more significant data for the definition of a correct diagnosis and clinical management of nGAS infections in children. Moreover, it is important to improve flu vaccination campaign and coverage to protect children from coinfections that could worsen the disease and misdiagnose the etiology of pharyngitis.

Integration of Group A Streptococcus Rapid Tests with the Open Fluidic CandyCollect Device.

The CandyCollect device is a lollipop-inspired open fluidic oral sampling device designed to provide a comfortable user sampling experience. We demonstrate that the CandyCollect device can be coupled with a rapid antigen detection test (RADT) kit designed for Group A Streptococcus (GAS). Through in vitro experiments with pooled saliva spiked with Streptococcus pyogenes we tested various reagents and elution volumes to optimize the RADT readout from CandyCollect device samples. The resulting optimized protocol uses the kit-provided reagents and lateral flow assay (LFA) while replacing the kit's pharyngeal swab with the CandyCollect device, reducing the elution solution volume, and substituting the tube used for elution to accommodate the CandyCollect device. Positive test results were detected by eye with bacterial concentrations as low as the manufacturer's "minimal detection limit" - 1.5×105 CFU/mL. LFA strips were also scanned and quantified with image analysis software to determine the signal-to-baseline ratio (SBR) and categorize positive test results without human bias. We tested our optimized protocol for integrating CandyCollect and RADT using CandyCollect clinical samples from pediatric patients (n=6) who were previously diagnosed with GAS pharyngitis via pharyngeal swabs tested with RADT as part of their clinical care. The LFA results of these CandyCollect devices and interspersed negative controls were determined by independent observers, with positive results obtained in four of the six participants on at least one LFA replicate. Taken together, our results show that CandyCollect devices from children with GAS pharyngitis can be tested using LFA rapid tests.

Cost-effectiveness and Accuracy Analysis of Different Screening Strategies for COVID-19

Background: Coronavirus disease 2019 (COVID-19) is mainly confirmed through reverse transcription polymerase chain reaction (RT-PCR), which is both expensive and time-consuming and requires specific equipment. Thus, demand for rapid diagnostic methods, such as rapid antigen detection (RAD) tests, has emerged. Here, we assessed the efficiency and reliability of RAD for early diagnosis of COVID-19. Methods: We performed a retrospective study based on systemic COVID-19 screening and diagnosis using RAD and RT-PCR at Taipei City Hospital during the first COVID-19 outbreak week in Taiwan (28 May-6 June 2021). We postulated five strategies for COVID-19 screening in the general population: one RAD test, one RT-PCR test, one RAD test (negative) followed by one RT-PCR, one RAD test (positive) followed by one RT-PCR test, and two RAD tests and calculated their cost and accuracy. We also conducted a cost-effectiveness analysis to identify the most economically efficient strategy for COVID-19 diagnosis. This study included 6368 cases in total. Results: Although RAD exhibited low sensitivity (mean 66%), other values were acceptable: mean specificity, positive predictive value, negative predictive value, and accuracy were 99%, 82.8%, 97.5%, and 94.2%, respectively. RAD was the most cost-effective method. Additionally, it may be an effective diagnostic strategy in the later stages of the epidemic, warranting further research. Conclusion: Although RT-PCR remains the standard method for diagnosing COVID-19, RAD is faster and a more cost-effective, convenient, and globally available method, allowing for early detection of SARS-CoV-2. conclusion: We propose that RAD could be a fast and feasible method for diagnosing SARS-CoV-2 infection, allowing for early detection. Although RT-PCR remains the standard method for diagnosing SARS-CoV-2 infection, RAD is a more cost-effective, convenient, fast, and globally available method.

Initial assessment and management of adults with suspected acute respiratory infection: a rapid evidence synthesis of reviews and cost-effectiveness studies.

This work was undertaken to inform a National Institute for Health and Care Excellence guideline on the initial assessment of adults with suspected acute respiratory infection. To undertake a rapid evidence synthesis of systematic reviews and cost-effectiveness studies of signs, symptoms and early warning scores for the initial assessment of adults with suspected acute respiratory infection. MEDLINE, EMBASE and Cochrane Database of Systematic Reviews were searched for systematic reviews and MEDLINE, EMBASE, EconLit and National Health Service Economic Evaluation Database were searched for cost-effectiveness studies in May 2023. References of relevant studies were checked. Clinical outcomes of interest included escalation of care, antibiotic/antiviral use, time to resolution of symptoms, mortality and health-related quality of life. Risk of bias was assessed using the Risk of Bias in Systematic Reviews tool or the National Institute for Health and Care Excellence economic evaluations checklist. Results were summarised using narrative synthesis. Nine systematic reviews and one cost-effectiveness study met eligibility criteria. Seven reviews assessed several early warning scores for patients with community- acquired pneumonia, one assessed early warning scores for nursing home-acquired pneumonia and one assessed individual signs/symptoms and the Centor score for patients with sore throat symptoms; all in face-to-face settings. Two good-quality reviews concluded that further research is needed to validate the CRB-65 in primary care/community settings. One also concluded that further research is needed on the Pneumonia Severity Index in community settings; however, the Pneumonia Severity Index requires data from tests not routinely conducted in community settings. One good-quality review concluded that National Early Warning Score appears to be useful in an emergency department/acute medical setting. One review (unclear quality) concluded that the Pneumonia Severity Index and CURB-65 appear useful in an emergency department setting. Two poor-quality reviews concluded that early warning scores can support clinical judgement and one poor-quality review found numerous problems with using early warning scores in a nursing home setting. A good-quality review concluded that individual signs and symptoms have a modest ability to diagnose streptococcal pharyngitis, and that the Centor score can enhance appropriate prescribing of antibiotics. The cost-effectiveness study assessed clinical scores and rapid antigen detection tests for sore throat, compared to delayed antibiotic prescribing. The study concluded that the clinical score is a cost-effective approach when compared to delayed prescribing and rapid antigen testing. Several early warning scores have been evaluated in adults with suspected acute respiratory infection, mainly the CRB-65, CURB-65 and Pneumonia Severity Index in patients with community-acquired pneumonia. The evidence was insufficient to determine what triage strategies avoid serious illness. Some early warning scores (CURB-65, Pneumonia Severity Index and National Early Warning Score) appear to be useful in an emergency department/acute medical setting; however, further research is required to validate the CRB-65 and Pneumonia Severity Index in primary care/community settings. The economic evidence indicated that clinical scores may be a cost-effective approach to triage patients compared with delayed prescribing. Only systematic reviews were eligible for inclusion in the synthesis of clinical evidence. There was a great deal of overlap in the primary studies included in the reviews, many of which had significant limitations. No studies were undertaken in remote settings (e.g. NHS 111). Only one cost-effectiveness study was identified, with limited applicability to the review question. This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number NIHR159945.

Diagnostic Performances of an in-House Immunochromatography Test Based on the Monoclonal Antibody 18B7 to Glucuronoxylomannan for Clinical Suspected Cryptococcosis: a Large-Scale Prototype Evaluation in Northern Thailand.

Cryptococcosis predominantly presents as a meningoencephalitis in Thailand. Early and expeditious diagnosis is essential for reducing both mortality and morbidity associated with cryptococcal meningitis. We aim to define and establish the diagnostic performances between the benchmark commercially available diagnostic kit (CrAg® LFA) and the large-scale prototype of an inexpensive in-house immunochromatographic test (ICT) based on monoclonal antibody (MAb) 18B7. We have developed the large-scale prototype for the rapid detection of cryptococcal polysaccharide antigens by utilizing a single antibody sandwich ICT format employing MAb 18B7, which is highly specific to Cryptococcus neoformans glucuronoxylomannan (GXM) antigens. An in-house MAb18B7 ICT was manufactured in accordance with industry standards under the control of the International Organization for Standardization (ISO) 13485. The diagnostic sensitivity, specificity, and accuracy for the in-house MAb 18B7 ICT were 99.10%, 97.61%, and 97.83%, respectively. The agreement kappa (κ) coefficient was 0.968 based on the retrospective evaluation of 580 specimens from patients living in northern Thailand with clinically suspected cryptococcosis. The data suggest that this in-house MAb 18B7 ICT will be highly beneficial for addressing the issue of cryptococcal infection in Thailand. Moreover, it is anticipated that this inexpensive ICT can play a pivotal role in various global strategies aimed at eradicating cryptococcal meningitis among individuals living with HIV by 2030.

Biofunctional photoelectrochemical/electrochemical immunosensor based on BiVO4/BiOI-MWCNTs and Au@PdPt for alpha-fetoprotein detection

A biofunctional immunosensor combining photoelectrochemical (PEC) and electrochemical (EC) was proposed for the quantitative detection of the liver cancer marker alpha-fetoprotein (AFP) in human blood. BiVO4/BiOI-MWCNTs photoactive materials were first prepared on conductive glass FTO, and the photoelectrode was functionalized by chitosan and glutaraldehyde. Then, the AFP capture antibody (Ab1) was successfully modified on the photoelectrode, and the label-free rapid detection of AFP antigen was achieved by PEC. In addition, Au@PdPt nanospheres were also used as a marker for binding to AFP detection antibody (Ab2). Due to the excellent catalytic properties of Au@PdPt in EC reaction, a signal increase in the EC response can be achieved when Ab2 binds to the AFP antigen, which ensures high sensitivity for the detection of AFP. The detection limits of PEC and EC are 0.050 pg/mL and 0.014 pg/mL, respectively. The sensor also possesses good specificity, stability and reproducibility, shows excellent performance in the detection of clinical samples and has good clinical applicability.

Rapid antigen detection of severe acute respiratory syndrome coronavirus-2 in stray cats: A cross-sectional study.

Although reverse zoonotic transmission events from humans to domestic cats have been described, there is currently little evidence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) circulation in stray cats. Due to the evidence of natural and experimental infections in cats and the capacity to disseminate the virus among them, this study aimed to identify the SARS-CoV-2 antigen in stray cats from the Federal University of Sergipe in Brazil. One hundred twenty six stray cats from the university were screened for SARS-CoV-2 antigens by random sampling. Throat swab samples were tested for the virus using rapid antigen detection tests. Of the 126 animals tested, 30 (23.60%) were positive for SARS-CoV-2 antigens. To our knowledge, for the first time, this study detected the SARS-CoV-2 antigen in stray cats and confirmed the presence of SARS-CoV-2 infections in Brazil's stray cat population. The detection of SARS-CoV-2 in stray cats poses a risk for infected and healthy animals and possibly for humans who attend the university daily. As a limitation of the study, the small sample size necessitates caution when interpreting the results. This underscores the need for further research in this area to help control diseases in stray animals during potential pandemics. This highlights the need for monitoring and controlling the spread of the virus in stray animal populations.

Stratification of Group A Streptococcal Pharyngitis Children Using Unsupervised Learning.

Background and objectives Group A Streptococcus (GAS) is the most frequent cause of bacterial pharyngitis, and it is advised to selectively use rapid antigen detection testing (RADT). Currently, the decision to perform this test is based on pediatricians' observations, but the criteria are not well-defined. Therefore, we utilized unsupervised learning to categorize patients based on the clinical manifestations of GAS pharyngitis. Our goal was to pinpoint the clinical symptoms that should prompt further examination and treatment in patients diagnosed with pharyngitis. Methods We analyzed categorical data from 305 RADT-positive patients aged three to 15 years using the K-modes clustering method. Each explanatory variable's relationship with cluster variables was statistically examined. Finally, we tested the differences between clusters for continuous variables statistically. Results The K-modes method categorized the cases into two clusters. Cluster 1 included older children with lymph node tenderness, while Cluster 2 consisted of younger children with cough and rhinorrhea. Conclusion Differentiating streptococcal pharyngitis from common cold or upper respiratory tract infection based on clinical symptoms alone is challenging, particularly in young patients. Future research should focus on identifying indicators that can aid in suspecting streptococcal infection in young patients.

Comparison of morbidity and absenteeism due to COVID-19 and seasonal influenza in a large cohort of health care personnel in the 2022 to 2023 season

To compare the morbidity and work absenteeism associated with coronavirus disease 2019 (COVID-19) and influenza among health care personnel (HCP) in 2022 to 2023. We followed 5,752 hospital-based HCP in Greece from November 14, 2022 through May 28, 2023. Symptomatic HCP was tested for SARS-CoV-2 and influenza by real-time polymerase chain reaction and/or rapid antigen detection test. The association between the duration of absenteeism and the type of disease was estimated by multivariable regression models. A total of 734 COVID-19 cases and 93 influenza cases were studied. The mean duration of absence per COVID-19 case was 5.8days compared with a mean of absence of 3.6days per influenza case (P value <.001). Overall, COVID-19 accounted for 4,245days missed during the study period compared with 333days missed due to influenza. Multivariable regressionestimates indicated that HCP with COVID-19 had 1.91 more days of absenteeism (95% confidence interval 1.67-2.15) compared with those with influenza, on average. As SARS-CoV-2 becomes endemic, COVID-19 remains the prevalent cause of morbidity and absenteeism among HCP, accounting for considerably more workdays missed compared with influenza. HCP should be up-to-date with COVID-19 booster vaccinations and annual influenza vaccination in order to protect them as well as health care systems from HCP absenteeism.

An Analogy between Gold Standard SARS-CoV-2 RT-qPCR with the SARS-CoV-2 Rapid Antigen Test in a Tertiary Care Setting in Central State of India

Reverse transcription-quantitative PCR (RT-qPCR)-based assays are extensively being utilized to detect coronavirus disease 2019 (COVID-19). However, due to a lack of RT-qPCR testing capability, these tests cannot be carried out in community clinics. The intention of our study was to evaluate the specificity and sensitivity of Rapid Antigen Detection (RAT) tests versus those of RT-qPCR using nasopharyngeal and oropharyngeal specimens. Respiratory swab specimens were collected from the COVID-19 patients admitted at Dr. Bhimrao Ambedkar Memorial Hospital, Raipur, CG, India, during March to April 2022. RAT and RT-qPCR were performed using standard methods as per guidebook instructions, and subjects were chosen using a convenience sample technique. 100 swabs from patients, who had earlier verified positive and 100 from who had earlier verified negative for SARS-CoV-2 via RT-qPCR, were taken for study. Study was approved by the institutional ethical committee before data collection and initiation of the study. We evaluated for the sensitivity and specificity of the STANDARD Q COVID-19 Ag test kit (SD Biosensor). On testing, an over-all sensitivity and specificity of the kit was recorded as 74% and 100%, respectively in comparison to the RT-qPCR kit. Further, the assay’s sensitivity was shown to be 100%, 94.87%, 77.27%, and 55.56%, respectively, for samples with cycle thresholds (Ct) of 15-25, 25-30, 30-35, and &gt;35. We draw the conclusion that the RT-qPCR assay has superior sensitivity and specificity to the antigen assay. However, in all situations where RT-qPCR testing is difficult, the antigen assay could serve as a rapid and simple option for separating SARS-CoV-2 contagious from non-contagious patients.

CdS/Bi2S3/NiS ternary heterostructure-based photoelectrochemical immunosensor for the sensitive detection of carbohydrate antigen 125

The sensitive, accurate and rapid detection of carbohydrate antigen 125 (CA125) is essential for the early diagnosis and clinical management of ovarian cancer, but there is still challenge. Herein, a photoelectrochemical (PEC) immunosensor based on CdS/Bi2S3/NiS ternary sulfide heterostructured photocatalyst was presented for the detection of CA125. The CdS/Bi2S3/NiS was synthesized by a one-step hydrothermal approach. The heterojunction comprising of CdS and Bi2S3 could separate photogenerated carriers, the introduced narrow bandgap NiS could act as electron-conducting bridge to facilitate the transfer of interfacial photogenerated electrons, thereby improving the photoelectric conversion efficiency. Due to their synergistic effect, the photocurrent response produced by the composite was up to 14.6 times of pure CdS. On the basis, a PEC immunosensor was constructed by introducing the CA125 antibody through thioglycolic acid linkage. It was found that the resulting immunosensor showed good performance. Under the optimized conditions, its linear detection range was as wide as 1 pg mL−1−50 ng mL−1, and the detection limit was low to 0.85 pg mL−1. Furthermore, we experimentally tested its anti-interference, stability and reproducibility, and satisfactory results were achieved. The practicable feasibility of the sensor was confirmed by testing serum sample. Thus this work provided a simple, fast and enough sensitive approach for CA125 monitoring.

A rapid simultaneous antigen detection of Haemophilus influenzae and Streptococcus pneumoniae for predicting the prognosis of acute otitis media

BackgroundRapid identification of causative bacteria in treatment of acute otitis media (AOM) is of paramount importance for appropriate antibiotic use. Materials and methodsThis prospective observational study was conducted in 15 hospitals and clinics in Japan between 2018 and 2020. A new rapid antigen test kit (AOS-116), which simultaneously detects antigens for Streptococcus pneumoniae (Sp) and Haemophilus influenzae (Hi), was applied for middle ear fluids (MEFs) and nasopharyngeal secretions (NPSs) in patients with moderate to severe AOM. We investigated relationship between the results of rapid test, severity at initial visit, and clinical course. ResultsRegarding performance accuracy based on culture results, AOS-116 showed 1) high (>80%) sensitivity, specificity, and negative predictive value (NPV) in MEFs for both antigens, 2) high sensitivity, specificity, and positive predictive value (PPV) in NPSs for Hi antigen, and 3) high specificity, and PPV in NPSs for Sp antigen. Regarding predictive value of nasopharyngeal culture and antigen detection for causative middle ear pathogens, similar results were observed between AOS-116 and culture, which was characterized with high sensitivity and NPV for both pathogens. MEFs/NPSs positive for Hi antigen were significantly associated with eardrum findings, and severity. MEFs/NPSs positive for pneumococcal antigen were significantly associated with severity of otalgia, fever, and otorrhea. Among patients with prior antimicrobial treatment, improvement tended to be slower in cases positive for Hi than in cases negative. ConclusionThe rapid antigen detection test is useful as a decision-making tool for prescribing antimicrobial agents and may play an important role in promoting appropriate antimicrobial use.

Measures implemented in the school setting to contain the COVID-19 pandemic.

Measures implemented in the school setting to contain the COVID-19 pandemic.

Development of a quantum dots based immunochromatographic strip for rapid and on-site detection of African swine fever virus

African swine fever (ASF) is a lethal disease caused by ASF virus (ASFV), severely impacting the global swine industry. Though nuclear acid-based detection methods are reliable, they are laboratory-dependent. In this study, we developed a device-independent, user friendly and cost-effective quantum dots based immunochromatographic strip (QDs-ICS) with high specificity and sensitivity for the rapid and on-site detection of ASFV antigen. For the preparation of the QDs-ICS, we generated a monoclonal antibody (mAb) mAb-8G8 and polyclonal antibody (pAb) against ASFV-p72 protein. The pAb was labelled with QDs to be used as the detection probe and the mAb-8G8 was coated on the nitrocellulose membrane as the test line. Our results proved that the strip displayed no cross-reactivity with other swine viruses and detection limit of the QDs-ICS was down to 1 ng/mL for the ASFV-p72 protein with great reproducibility. The strip also exhibited high stability with a storage period up to 12 months under room temperature. Twenty blind samples and one hundred clinical samples were examined by the QDs-ICS, conventional PCR and real-time PCR method, respectively. Results showed that the agreement rate between the QDs-ICS and PCR method was 100%, and the agreement rate between the strip and real-time PCR was 94%. The novel QDs-ICS developed here would be an effective tool for on-site detection of ASFV.