Antigen Test Kit Research Articles

Performance of Fujifilm Dengue NS1 Antigen Rapid Diagnosis Kit Compared to Quantitative Real-Time Polymerase Chain Reaction.

Dengue is a viral infection caused by the dengue virus (DENV), transmitted to humans through the bite of infected Aedes mosquitoes. About half of the world's population is now at risk of dengue, which represents a global public health concern, especially in tropical and subtropical countries. Early detection of the viral infection is crucial to manage the disease; hence, effective rapid diagnostic tests are essential. In this study, we evaluated the performance between the new Fujifilm Dengue non-structural antigen diagnosis kit (FF NS1 kit) and the SD Bioline NS1 antigen test kit (SD NS1 kit) against the quantitative real-time polymerase chain reaction (qRT-PCR) assays. The 140 acute serum samples collected from the Yangon General Hospital and Yangon Children's Hospital, Myanmar, from 2017 to 2019 were characterised by the three assays. With the qRT-PCR as the standard, the FF NS1 kit and the SD NS1 kit exhibited sensitivity of 94.3% and 88.6%, respectively, and specificity of 100% in both kits. Moreover, the positivity rates of the FF NS1 kit and the SD NS1 kit were 97.5% and 95% in primary infection and 90% and 80% in secondary infection, respectively. Our overall results suggest that the FF NS1 kit is reliable and accurate for detecting DENV infection.

ƩS COVID-19 is a rapid high throughput and sensitive one-step quadruplex real-time RT-PCR assay

Real-time reverse transcription polymerase chain reaction (RT-PCR), a standard method recommended for the diagnosis of coronavirus disease 2019 (COVID-19) requires 2–4 h to get the result. Although antigen test kit (ATK) is used for COVID-19 screening within 15–30 min, the drawback is its limited sensitivity. Hence, a rapid one-step quadruplex real-time RT-PCR assay: termed ƩS COVID-19 targeting ORF1ab, ORF3a, and N genes of SARS-CoV-2; and Avocado sunblotch viroid (ASBVd) as an internal control was developed. Based on strategies including designing high melting temperature primers with short amplicons, applying a fast ramp rate, minimizing hold time, and reducing the range between denaturation and annealing/extension temperatures; the assay could be accomplished within 25 min. The limit of detection of ORF1ab, ORF3a, and N genes were 1.835, 1.310, and 1 copy/reaction, respectively. Validation was performed in 205 combined nasopharyngeal and oropharyngeal swabs. The sensitivity, specificity, positive predictive value, and negative predictive value were 92.8%, 100%, 100%, and 97.1%, respectively with 96.7% accuracy. Cohen’s Kappa was 0.93. The newly developed rapid real-time RT-PCR assay was highly sensitive, specific, and fast, making it suitable for use as an alternative method to support laboratory diagnosis of COVID-19 in outpatient and emergency departments.

Equitable COVID-19 Testing Access for Underserved Communities: The Success of Vending Machines.

This study examines the pivotal role of COVID-19 testing in mitigating disease spread, particularly in underserved rural communities facing health care access challenges. The Southern Nevada Health District successfully implemented a vending program in Clark County, offering free COVID-19 antigen test kits. Strategically located based on health equity indices and featuring a user-friendly, multilingual registration process, these machines proved effective in reaching rural populations. The cost-effective model suggests potential adoption for broader public health interventions and services in other regions. (Am J Public Health. 2024;114(S7):S558-S561. https://doi.org/10.2105/AJPH.2024.307718).

Social Impact Assessment Project on Cholangiocarcinoma Screening and Care Program

The research aims to assess users utility and cost-effectiveness based on the results of rapid antigen test kits for urine and abdominal ultrasound methods. This study uses qualitative methods to analyze liver fluke screening among individuals aged 40 and above in four provinces. Purposive sampling was used, with 373 participants and 379 participants, respectively. Utility measurement tools included a direct Visual Analog Scale (VAS) and indirect EuroQoL (5Q-5D-5L), and willingness to pay value was measured using bidding. The result shows that the sample group has an average VAS score of 76.90, with slight pain or discomfort reported in the five health dimensions. The utility value reflecting daily quality of life is 0.89. The average willingness to pay per use for rapid test kits and abdominal ultrasounds is 187 baht and 796 baht, respectively. Reasons for not paying higher include income factors, high prices, and personal limitations. However, participants believe public hospitals could support examination costs and provide access to benefits. The project benefits people economically, socially, and culturally, and if the Ministry of Public Health and related agencies can effectively use it, it will maximize benefits.

High-throughput light-induced immunoassay with milliwatt-level laser under one-minute optical antibody-coating on nanoparticle-imprinted substrate

The efficient detection of protein biomarkers is critical for public health. However, the sensitivity of conventional antigen test kits is relatively low for early diagnosis, and laboratory immunoassays require complex pretreatment processes overnight. If target nanomaterials could be remotely guided to the detection site, simpler and faster methods would be developed. Here, we reveal the mechanism of light-induced immunoassay that anti-spike-protein antibodies for SARS-CoV-2 were coated on our developed nanoparticle-imprinted plasmonic substrate (NPI-PS) over the submillimeter area within one minute and nanoparticles modified with spike proteins can be selectively detected within a few minutes at one or two orders of higher sensitivity via a two-step optical condensation using NPI-PS. NPI-PS exhibits high-performance optical condensation with high photothermal properties even under milliwatt-class nonresonant laser irradiation, enabling a wide range of quantitative measurements. These findings support an innovative strategy to mitigate pandemic threats and various diseases through the high-throughput detection of protein biomarkers.

An Evaluation of the Sensitivity and Specificity of Three COVID-19 Rapid Immunochromatographic Test Kits Compared to Real-Time Reverse Transcriptase-Polymerase Chain Reaction (rRT-PCR) Among Clinical Samples.

Background and objective The coronavirus disease 2019 (COVID-19) pandemic has imposed a significant burden on healthcare systems worldwide. This highlights the need for simple, rapid, and affordable diagnostic tests that can serve as alternatives tothe existing costly and demanding polymerase chain reaction (PCR) assay, especially in resource-limited countries like Ghana. In light of this, we aimed to assess thediagnostic efficacy of threeCOVID-19 rapid immunochromatographic antigen test kits vs. real-time reverse transcriptase-PCR (rRT-PCR). Methods This study evaluated the sensitivity and specificity of threeCOVID-19 rapid immunochromatographic antigen test kits: DG Rapid, SD Rapid, and SS Rapid. They were compared with the gold standard RT-PCRfor the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid antigen in 75 randomly selected archived nasopharyngeal samples. Results Of the 75 samples tested, 38 (50.7%) were positive and 37 (49.3%) were negative for SARS-CoV-2 RNA by rRT-PCR assay. No false positives were recorded. On the other hand, the DG Rapid kit detected 30 (78.9%) true positives and eight (21.1%) false negatives. SD Rapid kit detected 28 (73.7%) true positives and 10 (26.3%) false negatives, while the SS Rapid kit detected 19 (50.0%) true positives and 19 (50.0%) false negatives. While the specificity of each test kit was 100% (95% CI),the sensitivity of the DG Rapid, SD Rapid, and SS Rapid kits was 79%, 74%, and 50% (95% CI), respectively. Higher sensitivitieswere recorded among samples with cycle threshold (Ct) values <29.99 for each kit. Also, the DG Rapid kit demonstrated 79% excellent agreement with rRT-PCR, while the SD Rapid and SS Rapid kits demonstrated good agreement with rRT-PCR with 73% and 50% Cohen's kappa values, respectively. Conclusions Based on our findings,DG Rapid and SD Rapid kits are reliable alternatives to rRT-PCR for the detection of SARS-CoV-2 infection, especially in resource-limited settings like Ghana.

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.

Identification of coronavirus disease marker compounds in sweat with comprehensive two dimensional gas chromatography using multiloop splitter-based non-cryogenic artificial trapping modulation system

This study applied comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GCMS–) for analysis of volatile compounds in headspaces of axillary swab samples of RT-PCR or antigen test kit proven COVID-19 positive and negative volunteers in Bangkok, Thailand. The separation was performed using a conventional Deans switch (DS) based heartcut system with an additional splitter system located between the first (1D) column (30 m) and the DS. The splitter consisted of deactivated fused silica (DFS) columns connected into three loops with the progressively doubled perimeters of the downstream loops. An artificial GC × GC result was obtained by applying a periodic heartcut (H/C) event within every artificial modulation period (PAM) of 1.14 min, selectively transferring the analytes onto the second (2D) column (30 m). Chemometric analysis including feature selection was used to identify significantly altered metabolites between the positive and negative groups. Fourteen significant metabolites were tentatively identified, including p-cymene, linalool, and 2,6,11-trimethyldodecane. The marker peak area thresholds were optimized by generating receiver operating characteristic (ROC) curves showing accuracy, sensitivity and selectivity within the ranges of 94–98%, 93–97% and 94–100%, respectively. Based on these results, we hypothesize that SARS-CoV-2 infection disrupts the metabolism of volatile metabolites in sweat, or impacts the microbiome, changing the volatile profile of sweat in infected patients.

2642. Multipathogen Antigen Test Kit (MAK-5) – Distribution and Frequency of Viral Respiratory Diseases in Germany among Volunteers in the VACCELERATE Registry

Abstract Background Currently, SARS-CoV-2 is the predominant viral respiratory pathogen. However, during winter season other viruses may cause acute respiratory infection (ARI). Most cases of non-severe ARI are not systematically tested, thus, distribution and epidemiology of these viruses is largely unknown. VACCELERATE is the EU funded consortium dedicated to vaccine research, running a volunteer registry and promoting clinical studies. Methods Adult registered subjects were invited to participate. Postal address was collected to allow sending of the MAK-5 test kit (BioTeke Corporation (Wuxi) Co., Ltd., Wuxi, Jiangsu, China). The availability of low-cost, sensitive and specific rapid tests detecting 5 pathogens (ADV, influenza viruses A and B, RSV, SARS-CoV-2) from one respiratory sample allowed us to conduct a feasibility study on their relative contribution to the burden of disease (BoD) outside any medical setting. Participants were instructed to use the test if respiratory symptoms were present for at least 24h. Test results and information on related symptoms and vaccinations were self-reported by e-mail. Underlying diseases were known from initial registration. Results Between 07-Dec-2022 and 01-May-2023, we processed test results from 1036 (52.1%) of 1990 participants. Including co-infections (N=18; 4.7%), we detected 384 infections: 178 (46.4%) SARS-CoV-2, 59 (32.8%) 104 (27.1%) RSV and 74 (19.3%) influenza A virus. ADV infection was detected in 10 (2.6%) volunteers and influenza B virus in 6 (1.6%). A total of 98.8% of tests yielded valid results, while 12 (1.2%) tests were invalid (negative control). While RSV was the most frequently detected virus in the first week of assessment (calendar week (CW) 49), there was a shift to Influenza A virus in CW 50, followed by a SARS-CoV-2 peaks in CW 51/22, 05/23, and 08/23. CW49/2022-CW18/2023 Conclusion This type of study allows assessment of the BoD by ARI pathogens before medical attention is sought and provides insights into the course of the annual (winter) infection waves down to a local level. Frequency of detected viruses varied over time. While SARS-CoV-2, RSV and influenza A virus were detected frequently, ADV and influenza B virus infections were rare. Disclosures Heinz-Josef Schmitt, n/a, VACCELERATE: Advisor/Consultant Jannik Stemler, -, Ministry of Education and Research (BMBF): Grant/Research Support Oliver A. Cornely, MD PhD, DZIF: Advisor/Consultant|DZIF: Board Member|DZIF: Grant/Research Support|DZIF: Honoraria|DZIF: Stocks/Bonds

Determinants of Intention to Repurchase Antigen Test Kit (ATK) Product

ATK test kits have been used widely to test for the Covid-19 virus. This has led to a significant demand and strong repurchase intentions for consumption by many people, including Thai people. From the marketing management perspective, repurchase intentions have been regarded as a competitive advantage which can greatly support firms not only to provide sufficient supply to the market but also to achieve business sustainability. Hence, many businesses have continued evaluating certain determinants which significantly influence their customers’ intentions to rebuy their products. In this regard, investigating the factors influencing repurchase intentions is essential to many businesses. Accordingly, this research aims to investigate how switching costs, brand experience, and brand loyalty, influence consumers’ intentions to rebuy antigen test kits (ATK) for testing for Covid-19 among Thai citizens. A google form survey was developed to survey 670 people who had previously bought an ATK. However, there were only 523 responses deemed valid and usable for analysis through a structural equation model. Results revealed that brand loyalty was significantly influenced by brand experience and switching costs. Consumers remained loyal to the same ATK brand if they were satisfied with their experience of using the ATK product. This could happen when they faced a high barrier of switching to another brand. Repurchase intentions were significantly influenced by brand loyalty and brand experience, but not switching cost. People rebought the ATK product when they remained loyal with the current ATK brand. Their intentions to rebuy became even higher once they had a good experience of using the product.&#x0D;

Clinical manifestations and outcomes of coronavirus disease 2019 among pediatric liver transplant recipients in the delta and omicron variant pandemic: A retrospective study.

To determine the clinical manifestations and outcomes of the coronavirus disease 2019 (COVID-19) in children who underwent liver transplantation (LT). A retrospective study was conducted at a transplant center in Thailand to include LT recipients aged < 18 years who had been infected with COVID-19. Out of a total of 54 children, there were 31 probable cases (57.4%) diagnosed using an antigen test kit and 23 confirmed cases (42.6%) diagnosed using polymerase chain reaction (14 children) or severe acute respiratory syndrome coronavirus 2 antigen (9 children). Approximately half of the children (25, 46.3%) received the BNT162b2 vaccine before the infection, with 3 and 2 doses in 5 and 18 children, respectively. While some had COVID-19 during the delta pandemic, most (46 children, 85.2%) were infected during the omicron pandemic, of which manifestations included fever (67.4%), cough (50%), and rhinorrhea (47.8%), and symptoms lasted approximately 3 days. None had severe diseases. All patients with mild-to-moderate disease were advised to continue the same immunosuppressive therapy as before the infection. Compared to unvaccinated children or children with one dose of the vaccine, fever was less common in those who received ≥ 2 doses (OR: 0.08; 95%CI: 0.01-0.57, adjusted for age and immunosuppressive types). Favipiravir was prescribed in most patients (90.7%). Only a few children had long COVID-19 or abnormal liver function tests lasting > 1 month (4 children, 7.4%, both). Pediatric LT recipients with COVID-19 during the delta and omicron variant pandemic reported mild symptoms despite undergoing immunosuppressive therapy.

A-364 The Utility of the Highly Sensitive Detection System for Immunochromatographic Assay by Addition of MPC polymer

Abstract Background Immunochromatographic assay (ICA) is frequently used as a point-of-care testing (POCT) in the field of infectious diseases, but it has a problem of low detection sensitivity. Many interfering substances in ICA test materials have been reported to case a decrease in detection sensitivity. For the purpose of increasing the sensitivity of ICA, bovine serum albumin or a polymer with phosphorylcholine groups (MPC polymer) has been used as an additive to a sample diluent. In this study, we evaluated the usability of the sensitizing effect for the addition of MPC polymer with a serum-based HBs antigen test kit. Methods A 2-fold dilution series of a commercially available control serum (Infectrol D, SeraCare Life Sciences, Inc. manufacturer's reference value 108.674 IU/mL) containing 0.05%, 0.10%, 0.5% of several MPC polymers (Biolipidure® from NOF Corporation) as final concentration were prepared with HBs antigen negative serum. The optimal type of MPC polymer and the concentrations added to the sera were determined by comparing the color intensity of their test lines in the evaluation of each test sample with a commercially available test kit (Quick Chaser® from MIZUHO MEDY Co., Ltd.). The color intensities of the test lines were quantified with an immunochromatographic reader. In addition, the correlation of two different test kits (ESPLINE® from FUJIREBIO and Quick Chaser® from MIZUHO MEDY Co., Ltd.) was evaluated with sera obtained from HBs antigen-positive patients regarding the three types of MPC polymer which were improved the detection sensitivity in the evaluation with the control serum. The measurements were performed in triplicate after 0.5% of MPC polymer as final concentration was added to each diluted serum. Results Antigen amount for diluted sera with MPC polymer were determined by CLEIA method, and no difference in the antigen amount was observed regardless of the addition or the types of MPC polymer. In addition, the color intensity in each dilution series was compared to the cutoff value, which is average value of the color intensity of negative control serum without MPC polymer. In the evaluation with control serum, the test line in the case without MPC polymer enabled to detect up to 2-fold diluted control serum while the test line in the case with MPC polymer enabled to detect up to 32-fold diluted control serum. The addition of MPC polymer in the evaluation with sera obtained from HBs antigen-positive patients was also confirmed that the detection sensitivity enhanced up to 8-fold higher in ESPLINE® and up to 4-fold higher in Quick Chaser®. Conclusion The color intensity of the test line enhanced by the addition of MPC polymer. In particular, when the highly hydrophilic and anionic MPC polymer was added, the test line was detected narrower and darker, and we believe that the increased color intensity resulted in improved sensitivity. By considering the influence of interfering substances in clinical materials and the physical properties of the MPC polymer (hydrophobicity, molecular size, etc.), it is expected that the sensitivity of the ICA will be increased to be more suitable for clinical materials.

Association of neighborhood-level sociodemographic factors with Direct-to-Consumer (DTC) distribution of COVID-19 rapid antigen tests in 5 US communities

BackgroundMany interventions for widescale distribution of rapid antigen tests for COVID-19 have utilized online, direct-to-consumer (DTC) ordering systems; however, little is known about the sociodemographic characteristics of home-test users. We aimed to characterize the patterns of online orders for rapid antigen tests and determine geospatial and temporal associations with neighborhood characteristics and community incidence of COVID-19, respectively.MethodsThis observational study analyzed online, DTC orders for rapid antigen test kits from beneficiaries of the Say Yes! Covid Test program from March to November 2021 in five communities: Louisville, Kentucky; Indianapolis, Indiana; Fulton County, Georgia; O’ahu, Hawaii; and Ann Arbor/Ypsilanti, Michigan. Using spatial autoregressive models, we assessed the geospatial associations of test kit distribution with Census block-level education, income, age, population density, and racial distribution and Census tract-level Social Vulnerability Index. Lag association analyses were used to measure the association between online rapid antigen kit orders and community-level COVID-19 incidence.ResultsIn total, 164,402 DTC test kits were ordered during the intervention. Distribution of tests at all sites were significantly geospatially clustered at the block-group level (Moran’s I: p < 0.001); however, education, income, age, population density, race, and social vulnerability index were inconsistently associated with test orders across sites. In Michigan, Georgia, and Kentucky, there were strong associations between same-day COVID-19 incidence and test kit orders (Michigan: r = 0.89, Georgia: r = 0.85, Kentucky: r = 0.75). The incidence of COVID-19 during the current day and the previous 6-days increased current DTC orders by 9.0 (95% CI = 1.7, 16.3), 3.0 (95% CI = 1.3, 4.6), and 6.8 (95% CI = 3.4, 10.2) in Michigan, Georgia, and Kentucky, respectively. There was no same-day or 6-day lagged correlation between test kit orders and COVID-19 incidence in Indiana.ConclusionsOur findings suggest that online ordering is not associated with geospatial clustering based on sociodemographic characteristics. Observed temporal preferences for DTC ordering can guide public health messaging around DTC testing programs.

Molecular Diagnosis and Haemato-biochemical Alteration in Canine Parvoviral Infection in Dogs

The present study was undertaken to diagnose and assess the haematological &amp; biochemical alteration in parvoviral gastroenteritis in dogs. Total of 12 dogs suspected for parvovirus infection were diagnosed by using lateral flow-based immunochromatographic assay rapid canine parvovirus (CPV) antigen test kit and polymerase chain reaction (PCR) technique in the faeces of affected dogs. All 12 dogs were found positive by a rapid antigen test kit and VP2 gene of CPV PCR assay using the CPV-2ab primer pair and expected size of 681 bp. The haemato-biochemical study revealed a decrease in Hb, TEC, serum total protein, albumin and globulin, whereas the increase in absolute neutrophil count and BUN in parvovirus-infected dogs, indicated anemia and hypoproteinemia in parvovirus infected dogs.

COVID-19 and Tuberculosis: Unveiling the Dual Threat and Shared Solutions Perspective.

The year 2020 will likely be remembered as the year dominated by COVID-19, or coronavirus disease. The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for this pandemic, can be traced back to late 2019 in China. The COVID-19 pandemic has significantly impacted the tuberculosis (TB) care system, reducing TB testing and reporting. This can be attributed to the disruption of TB services and restrictions on patient movement, consequently increasing TB-related deaths. This perspective review aims to highlight the intersection between COVID-19 and TB, highlighting their dual threat and identifying shared solutions to address these two infectious diseases effectively. There are several shared commonalities between COVID-19 and tuberculosis, particularly the transmission of their causative agents, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Mycobacterium tuberculosis. Both pathogens are transmitted via respiratory tract secretions. TB and COVID-19 are diseases that can be transmitted through droplets and airborne particles, and their primary target is typically the lungs. Regarding COVID-19 diagnostics, several methods are available for rapid and accurate detection. These include RT-PCR, which can provide results within two hours, and rapid antigen test kits that offer results in just a few minutes. The availability of point-of-care self-testing further enhances convenience. On the other hand, various approaches are employed for TB diagnostics to swiftly identify active TB. These include sputum microscopy, sputum for reverse transcription polymerase chain reaction (RT-PCR), and chest X-rays. These methods enable the rapid detection of active TB on the same day, while culture-based testing may take significantly longer, ranging from 2 to 8 weeks. The utilization of diverse diagnostic tools helps ensure the timely identification and management of COVID-19 and TB cases. The quality of life of patients affected by COVID-19 and tuberculosis (TB) can be significantly impacted due to the nature of these diseases and their associated challenges. In conclusion, it is crucial to emphasize the urgent need to address the dual threat of COVID-19 and TB. Both diseases have devastated global health, and their convergence poses an even greater challenge. Collaborative efforts, research investments, and policy reforms are essential to tackle this dual threat effectively.

An effective salivation-facilitating method for COVID-19 testing: An experimental study.

Simple tools, such as antigen test kits, are readily available for determining coronavirus disease 2019 infection at hospitals and homes. However, it is challenging for elderly people who are prone to dry mouth and other diseases. The main objective of this study was to investigate whether the presence or consumption of a plum pickle can facilitate salivation during coronavirus disease 2019 testing. Twenty healthy adult women participated in the study. The participants were allocated to 2 groups: presentation and non-presentation (n = 10; with and without presentation of a plum pickle, respectively), and eating and non-eating (n = 10; with and without consumption of plum pickle, respectively). We recorded the number of saliva swallows in 1 minute under each condition, using a swallowing test device, which attached film sensors to the hyoid bone and thyroid cartilage. There was a significant difference in the number of swallows between the non-presentation and presentation groups ( P < .01, r = 0.89, Z = -2.82) as well as between the non-eating and eating groups ( P < .01, r = 0.85, Z = -2.68). The strength of 3 factors, namely: direct stimulation with citric acid, saliva buffer capacity, and motor learning, may have affected the results. Our study suggests that saliva collection using the plum pickle is an effective complementary method for facilitating salivation. This technique may be useful in avoiding the risk associated with citric acid intake and for efficient specimen collection during coronavirus disease 2019 testing. In the future, we need to verify this method in elderly participants in a clinical setting.

The Decentralized Generation of Public Knowledge during the COVID-19 Pandemic: Examples from Australia

In the early days of the COVID-19 pandemic of 2020–2022, public uncertainty about the nature of the virus, and in particular its symptoms and mode of transmission, was met by the daily briefings issued by public health departments and political leaders. They were ill-equipped to respond to emerging knowledge management demands in an agile fashion. As this paper will show, this gap was filled on a volunteer basis by personal initiative. Examples for this are contact tracing register applications, an archive of daily COVID-19 incidence numbers at local government levels and a crowdsourced site that allowed the public find rapid antigen test kits during a time of extreme shortages. Once government and professional bodies eventually caught up and supplanted these volunteer endeavours, they become obsolete and by and large forgotten. Yet it can be posited that societal angst would have been much greater without them.

Dirofilaria immitis Identified in Galapagos Sea Lions (Zalophus wollebaeki): A Wildlife Health and Conservation Concern.

The Galapagos sea lion (Zalophus wollebaeki), an endemic and endangered pinniped, faces an increasing threat due to infectious diseases related to domestic animals. Dirofilaria immitis, the parasite responsible for canine heartworm disease, is one such threat, as canine infections on the archipelago have been documented. We used a canine heartworm antigen test kit to analyze the blood from 25 juvenile Galapagos sea lions for D. immitis. Two (8%) sea lions tested positive for D. immitis antigen. Using morphologic and genetic assessments, we evaluated 20 filarial-like worms collected from within the heart of an adult male Galapagos sea lion during a previous routine postmortem examination. The intracardiac worms were morphologically consistent with adult D. immitis, and sequence analysis of targeted PCR amplicons confirmed their identity. This is the first report of D. immitis infection in Galapagos sea lions, which could become a major health problem for these pinnipeds. Further studies are necessary to confirm the level of threat from this parasite; however, widespread adoption of routine heartworm testing, prevention, and treatment in the canine population, and the control of mosquitos, could potentially reduce the disease impact on this endangered pinniped species.

Rapidly adaptable automated interpretation of point-of-care COVID-19 diagnostics

BackgroundPoint-of-care diagnostic devices, such as lateral-flow assays, are becoming widely used by the public. However, efforts to ensure correct assay operation and result interpretation rely on hardware that cannot be easily scaled or image processing approaches requiring large training datasets, necessitating large numbers of tests and expert labeling with validated specimens for every new test kit format.MethodsWe developed a software architecture called AutoAdapt POC that integrates automated membrane extraction, self-supervised learning, and few-shot learning to automate the interpretation of POC diagnostic tests using smartphone cameras in a scalable manner. A base model pre-trained on a single LFA kit is adapted to five different COVID-19 tests (three antigen, two antibody) using just 20 labeled images.ResultsHere we show AutoAdapt POC to yield 99% to 100% accuracy over 726 tests (350 positive, 376 negative). In a COVID-19 drive-through study with 74 untrained users self-testing, 98% found image collection easy, and the rapidly adapted models achieved classification accuracies of 100% on both COVID-19 antigen and antibody test kits. Compared with traditional visual interpretation on 105 test kit results, the algorithm correctly identified 100% of images; without a false negative as interpreted by experts. Finally, compared to a traditional convolutional neural network trained on an HIV test kit, the algorithm showed high accuracy while requiring only 1/50th of the training images.ConclusionsThe study demonstrates how rapid domain adaptation in machine learning can provide quality assurance, linkage to care, and public health tracking for untrained users across diverse POC diagnostic tests.

Dynamic alterations in white blood cell counts and SARS-CoV-2 shedding in saliva: an infection predictor parameter.

The recent coronavirus (COVID-19) outbreak posed a global threat and quickly escalated to a pandemic. However, accurate information on potential relationships between SARS-CoV-2 shedding in body fluids, especially saliva, and white blood cell (WBC) count is limited. In the present study we investigated the potential correlation between alterations in blood cell counts and viral shedding in saliva in a cohort of COVID-19 patients. In this preliminary clinical research, 24 age-matched COVID-19 patients without comorbidities, 12 (50%) men and 12 (50%) women, were followed up for a period of 5 days to investigate whether changes in the level of viral shedding in saliva might parallel with temporal alterations in WBC count. Viral shedding in saliva was qualitatively measured by performing SARS-CoV-2 rapid antigen tests on patient saliva samples, using SARS-CoV-2 Rapid Antigen Test Kit (Roche, Basel, Switzerland). These patients were classified into two groups with sputum and non-sputum cough. WBCs counts including leukocyte (LYM), neutrophil (NEU), and LYM counts were recorded for each patient on days 1, 3, and 5. The results of the present study showed that the levels of WBC, LYM, and NEU as well as erythrocyte sedimentation rate (ESR) increased significantly on the 5th day compared to the first day in both groups with sputum. However, the levels of C-reactive protein (CRP), Neutrophil-to-Lymphocyte Ratio (NLR) and lactate dehydrogenase (LDH) did not show significant changes. This study proves that investigating the change in the number of blood LYMs as well as laboratory parameters such as CRP, LDH, and ESR as biomarkers is an accurate indicator to detect the amount of viral shedding in people with sputum and non-sputum. The results of our study denote that the measured parameters exhibit the intensity of viral shedding in people with sputum.