A cost-consequence analysis of the Xpert Xpress CoV-2/Flu/RSV plus test strategy for the diagnosis of influenza-like illnesses.

AIMS: Influenza-like illnesses (ILI) affect millions each year in the United States (US). Determining definitively the cause of symptoms is important for patient management. Xpert Xpress CoV-2/Flu/RSV plus (Xpert Xpress) is a rapid, point-of-care (POC), multiplex real-time polymerase chain reaction (RT-PCR) test intended for the simultaneous qualitative detection and differentiation of SARS-CoV-2, influenza A/B, and respiratory syncytial virus (RSV). The objective of our analysis was to develop a cost-consequence model (CCM) demonstrating the clinico-economic impacts of implementing PCR testing with Xpert Xpress compared to current testing strategies. METHODS: A decision tree model, with a 1-year time horizon, was used to compare testing with Xpert Xpress alone to antigen POC testing and send-out PCR strategies in the US outpatient setting from a payer perspective. A hypothetical cohort of 1,000,000 members was modeled, a portion of whom develop symptomatic ILIs and present to an outpatient care facility. Our main outcome measure is cost per correct treatment course. RESULTS: The total cost per correct treatment course was $1,131 for the Xpert Xpress strategy compared with a range of $3,560 to $5,449 in comparators. POC antigen testing strategies cost more, on average, than PCR strategies. LIMITATIONS: Simplifying model assumptions were used to allow for modeling ease. In clinical practice, treatment options, costs, and diagnostic test sensitivity and specificity may differ from what is included in the model. Additionally, the most recent incidence and prevalence data was used within the model, which is not reflective of historical averages due to the SARS-CoV-2 pandemic. CONCLUSION: The Xpert Xpress CoV-2/Flu/RSV plus test allows for rapid and accurate diagnostic results, leading to reductions in testing costs and downstream healthcare resource utilization compared to other testing strategies. Compared to POC antigen testing strategies, PCR strategies were more efficient due to improved diagnostic accuracy and reduced use of confirmatory testing.

Enhancing malaria detection in resource-limited areas: A high-performance colorimetric LAMP assay for Plasmodium falciparum screening.

Malaria eradication efforts in resource-limited areas require a rapid, economical, and accurate tool for detecting of the low parasitemia. The malaria rapid diagnostic test (mRDT) is the most suitable for on-site detection of the deadliest form of malaria, Plasmodium falciparum. However, the deletions of histidine rich protein 2 and 3 genes are known to compromise the effectiveness of mRDT. One of the approaches that have been explored intensively for on-site diagnostics is the loop-mediated isothermal amplification (LAMP). LAMP is a one-step amplification that allows the detection of Plasmodium species in less than an hour. Thus, this study aims to present a new primer set to enhance the performance of a colorimetric LAMP (cLAMP) for field application. The primer binding regions were selected within the A-type of P. falciparum 18S rRNA genes, which presents a dual gene locus in the genome. The test result of the newly designed primer indicates that the optimal reaction condition for cLAMP was 30 minutes incubation at 65°C, a shorter incubation time compared to previous LAMP detection methods that typically takes 45 to 60 minutes. The limit of detection (LoD) for the cLAMP using our designed primers and laboratory-grown P. falciparum (3D7) was estimated to be 0.21 parasites/µL which was 1,000-fold higher than referencing primers. Under optimal reaction condition, the new primer sets showed the sensitivity (100%, 95% CI: 80.49-100%) and specificity (100%, 95% CI: 94.64-100%) with 100% (95% CI: 95.70-100%) accuracy on the detection of dried blood spots from Malawi (n = 84). Briefly, the newly designed primer set for P. falciparum detection exhibited high sensitivity and specificity compared to referenced primers. One great advantage of this tool is its ability to be detected by the naked eye, enhancing field approaches. Thus, this tool has the potential to be effective for accurate early parasite detection in resource-limited endemic areas.

Testagem Molecular para Detecção de HPV e rastreamento do câncer do colo do útero / Molecular Testing for HPV Detection and Uterus Colon Cancer Tracking

INTRODUÇÃO: Evidências científicas robustas indicam que o rastreamento com testes moleculares para detecção de HPV oncogênico é mais sensível, eficaz/efetivo e eficiente, em termos do aumento de detecção de lesões precursoras e da redução da incidência e mortalidade por CCU, do que o rastreio com exame citopatológico. Outro aspecto fundamental é a maior detecção de casos de CCU em estágio inicial, precedendo em até 10 anos o diagnóstico pelo exame citopatológico. A detecção precoce leva a tratamentos menos mutilantes e onerosos, com excelente prognóstico e até com possibilidade de cura, impactando positivamente a custo-efetividade do rastreamento. Ademais, por apresentarem maior sensibilidade e valor preditivo negativo (VPN), quando comparados à citologia, os testes para detecção de HPV de alto risco permitem o aumento da idade de início do rastreio e do intervalo de testagem, melhorando a eficiência e otimizando o desempenho dos programas. PERGUNTA: "A testagem molecular para detecção de HPV

Comparative evaluation of the detection rate, workflow and associated costs of a multiplex PCR panel versus conventional methods in diagnosis of infectious gastroenteritis.

Introduction. Infectious gastroenteritis is a common reason for consulting a physician. Although most cases of gastrointestinal illness are self-limiting, the identification of the etiologic pathogen by stool specimen analysis is important in cases of more severe illness and for epidemiological reasons.Due to the broad range of causative pathogens, the conventional examination of a stool specimen is labour-intensive and usually requires different diagnostic methods. Multiplex PCR tests [e.g. BioFire Gastrointestinal (GI) Panel] allow the rapid detecting of up to 22 pathogens in one test.Hypothesis. Using a multiplex PCR panel to test stool specimens for infectious gastroenteritis pathogens can improve the detection rate, reduce the time-to-result and hands-on time and lower the costs of a microbiology laboratory.Aim. This study was aimed at evaluating the detection rate, the workflow and associated costs of stool specimen management using the BioFire GI Panel versus conventional methods.Methodology. Stool specimens were evaluated prospectively during the routine operation. Pathogen detection rate, hands-on time, time-to-result and material and personnel costs were determined for the BioFire GI Panel and conventional methods-the latter based on physician request and excluding viral testing.Results. Analysing 333 specimens collected between 2019 and 2020, the detection rate of enteropathogens was significantly higher with a positivity rate of 39.9 % using the multiplex PCR panel compared with 15.0 % using the conventional methods. The BioFire GI Panel presented results in a median time of 2.2 h compared with 77.5 h for culture and 22.1 h for antigen testing, noting that no tests were performed at weekends except for toxinogenic Clostridioides difficile. Based on list prices, the BioFire GI Panel was nine times more expensive compared with conventional methods, whereas hands-on-time was significantly lower using the BioFire GI Panel.Conclusion. Multiplex PCR panels are valuable tools for laboratory identification of infectious agents causing diarrhoea. The higher costs of such a multiplex PCR panel might be outweighed by the higher detection rate, ease of handling, rapid results and most likely improved patient management. However, these panels do not provide information on antimicrobial susceptibility testing. Therefore, if this is necessary for targeted therapy or if outbreak monitoring and control is required, specimens must still be cultured.

Advancing Chikungunya Diagnosis: A Cost-Effective and Rapid Visual employing Loop-mediated isothermal reaction.

The diagnosis of Chikungunya (CHIKV), along with the simultaneous monitoring of virus circulation in the population or vectors, is essential for global health. Although effective diagnostic methods for CHIKV, such as RT-qPCR, exist, their utilization is constrained by high costs. With the aim of contributing to the field of diagnostics, we have developed a diagnostic assay using isothermal amplification technology with visually interpretable results. This test can detect the virus within a maximum timeframe of 30 minutes. The detection limit of RT-LAMP CHIKV was found to be 66 copies of RNA molecules (Ct ≅ 31.28), and no cross-reactivity with other arboviruses was observed. During test validation, our assay demonstrated a sensitivity of 80.43%, specificity of 100%, and an overall accuracy of 88.89%. By utilizing more cost-effective reagents and equipment compared to RT-qPCR, this test holds the potential for broader application and enhanced accessibility, particularly in point-of-care settings.

Assessment of measurement accuracy of amplified DNA using a colorimetric loop-mediated isothermal amplification assay.

A colorimetric loop-mediated isothermal amplification assay detects changes in pH during amplification based on color changes at a constant temperature. Currently, various studies have focused on developing and assessing molecular point-of-care testing instruments. In this study, we evaluated amplified DNA concentrations measured using the colorimetric LAMP assay of the 1POT™ Professional device (1drop Inc, Korea). Results of the 1POT analysis of clinical samples were compared with measurements obtained from the Qubit™ 4 and NanoDrop™ 2000 devices (both from Thermo Fisher Scientific, MA, USA). These results showed a correlation of 0.98 (95% CI: 0.96-0.99) and 0.96 (95% CI: 0.92-0.98) between 1POT and the Qubit and NanoDrop. 1POT can measure amplified DNA accurately and is suitable for on-site molecular diagnostics.

Assessment of the capacity of Whatman filter papers as support to store stools for the molecular diagnostic testing of soil-transmitted helminthiasis.

Storage of stools for the detection of soil-transmitted helminths (STH) remains challenging for the molecular diagnostic testing of STH infections. This study aimed to overcome this challenge by assessing the capacity of Whatman filter papers to store stools for the molecular detection of STHs. Stool samples were collected from school-aged children of soil-transmitted helminthiasis endemic areas of Cameroon and then, analysed using Kato Katz technique. For this study, 128 and 40 stool samples respectively with and without STH eggs were analysed. From each sample, 10, 20, 40 and 80 mg of stool were weighted and spread on 6 grades of Whatman filter papers that were stored at room temperature from one to ten weeks. DNA was extracted from spread stool using CTAB based-method. The amount of stool to spread on filter papers and the grade of filter paper offering good storage were determined by amplifying specific DNA fragments of Ascaris lumbricoides. The capacity of filter papers to store stool samples for several weeks before the molecular detection of STH species was assessed by amplifying specific DNA fragments of different STHs. The amplification rates of A. lumbricoides were significantly higher (P < 0.0001) for 10 and 20 mg of stored stools. Stools spread on Whatman paper grade 2 yielded the highest amplification rate of 100% for A. lumbricoides, T. trichiura and hookworm. PCR revealed STH infections in all the 128 spread stools carrying STH eggs. It also revealed Necator americanus and Ancylostoma duodenale respectively in 10 and 13 of 15 spread stools contained hookworm eggs. PCR confirmed the co-infections of these hookworm species as well as that of A. lumbricoides and Trichuris trichiura in 7 spread stools. Out of 40 stools without STH eggs, PCR revealed that 5 (12.5%) and 9 (22.5%) had respectively A. lumbricoides and T. trichiura infections. The amplification rate of each STH species was 100% from one to 8 weeks and decreased to 86.7% after 10 weeks of storage. This study highlighted the capacity of filter papers to store stools for the molecular detection of STHs. Storing stools on these papers will enable to monitor and evaluate control programs and ensure post-elimination surveillance.

Alternativas de procesos para la búsqueda de casos de tuberculosis bajo condiciones económicas limitadas. Cuba 2022-2025 / Process Alternatives for the Tuberculosis Case Finding under Limited Economic Conditions. Cuba 2022-2025

Ejecutar procesos efectivos de búsqueda de casos de tuberculosis es crucial para acele-rar el paso hacia su eliminación. El empeoramiento de las condiciones económicas mun-diales y nacionales no nos permite aplicar extensivamente las tecnologías rápidas mo-leculares idóneas de diagnóstico. Consideramos sensato entonces aplicar algoritmos alternativos que satisfagan las necesidades nacionales presentes hasta que las condi-ciones permitan la cobertura completa de las tecnologías moleculares recomendadas. Sugerimos introducir la radiografía digital para todos los algoritmos, utilizar mejor la microscopía de fluorescencia LED y la óptica convencional ya probadas. En conclusión, es preciso que este enfoque de trabajo, que procura optimizar la efectividad y eficiencia del programa, se introduzca en la práctica cotidiana hasta que lo idóneo sea permisible

Executing effective tuberculosis case-finding processes is crucial to accelerate the path towards elimination of the disease. The worsening of global and national economic conditions do not allow us to extensively apply rapid molecular diagnostic technolo-gies. We consider it sensible and necessary to apply alternative algorithms that meet the current national needs, until conditions allow full coverage of the recommended molecular technologies. We suggest introducing digital X-rays for all algorithms, bet-ter use of LED fluorescence microscopy and conventional optics already appropriate-ly tested. In conclusion, it is necessary that this approach that seeks to optimize the effectiveness and efficiency of the Cuban program be introduced into daily practice until the ideal is permissible

Rapid On-Site Detection of SARS-CoV-2 Using RT-LAMP Assay with a Portable Low-Cost Device.

Emerging infectious diseases pose a serious threat to human health and affect social stability. In recent years, the epidemic situation of emerging infectious diseases is very serious; among these infectious diseases, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected many countries and regions in a short time. The prevention and treatment of these diseases require rapid on-site detection methods. However, the common detection method, RT-PCR, requires expensive instruments, complex operations, and professional operators. Here, we developed a portable low-cost assay for rapid on-site detection of viral nucleic acid using reverse transcription-loop-mediated isothermal amplification (RT-LAMP). The SARS-CoV-2 RNA can be successfully amplified within 15 min in a thermos, and the detection result is read rapidly in a portable low-cost device with a sensitivity of 100 copies/µL. The portable low-cost device consists of a black box, a laser or LED and a filter, costing only a few cents. The rapid on-site detection method can provide strong support for the control of biological threats such as infectious diseases. It is also an emergency detection method for low-resource settings, relieving the huge pressure on health care.

Assessment of the clinical and analytical performance of the Aptima SARS-CoV-2 assay using the VALCOR protocol.

BACKGROUND: The COVID-19 pandemic highlighted the importance of diagnostic testing against curbing the spread of SARS-CoV-2. The urgent need and scale for diagnostic tools resulted in manufacturers of SARS-CoV-2 assays receiving emergency authorization that lacked robust analytical or clinical evaluation. As it is highly likely that testing for SARS-CoV-2 will continue to play a central role in public health, the performance characteristics of assays should be evaluated to ensure reliable diagnostic outcomes are achieved. METHODS: VALCOR or "VALidation of SARS-CORona Virus-2 assays" is a study protocol designed to set up a framework for test validation of SARS-CoV-2 virus assays. Using clinical samples collated from VALCOR, the performance of Aptima SARS-CoV-2 assay was assessed against a standard comparator assay. Diagnostic test parameters such as sensitivity, specificity and overall per cent agreement were calculated for the clinical performance of Aptima SARS-CoV-2 assay. RESULTS: A total of 180 clinical samples were tested with an addition of 40 diluted clinical specimens to determine the limit of detection. When compared to the standard comparator assay Aptima had a sensitivity of 100.0% [95% CI 95.9-100.0] and specificity of 96.7% [95% CI 90.8-99.3]. The overall percent agreement was 98.3% with an excellent Cohen's coefficient of κ = 0.967 [95% CI 0.929-1.000]. For the limit of detection, Aptima was able to detect all of the diluted clinical samples. CONCLUSION: In conclusion. validation of Aptima SARS-CoV-2 assay using clinical samples collated through the VALCOR protocol showed excellent test performance. Additionally, Aptima demonstrated high analytical sensitivity by detecting all diluted clinical samples corresponding to a low limit of detection.

Reverse-Transcription Loop-Mediated Isothermal Amplification and alternative protocols for lower cost, large-scale COVID-19 testing: lessons from an emerging economy / Amplificación isotérmica mediada por bucle de transcripción inversa y protocolos alternativos para pruebas COVID-19 a gran escala y de bajo costo: lecciones de una economía emergente

Abstract Introduction: Most successful cases of COVID-19 pandemic mitigation and handling have relied on extensive reverse-transcription quantitative polymerase chain reaction (RT-qPCR). However, many emerging economies have struggled with current molecular testing demands due to economic, technical and technological constraints. Objective: To define a potential diagnostic protocol to increase testing capacity in current and post-pandemic conditions. Methods: We reviewed the literature, patents and commercial applications, for alternatives. Results: We found a good potential in saliva samples, viral inactivation and quick RNA extraction by heating; the use of an isothermal technology such as loop mediated isothermal amplification (LAMP) and naked eye test-result visualization by in-tube colorimetry or turbidity. Conclusions: Saliva samples with quick RNA extraction by heating and colorimetric LAMP are promising options for countries with economic and infrastructure limitations.

Resumen Introducción: La mayoría de los casos exitosos de mitigación y manejo de la pandemia de COVID-19 se han dado mediante pruebas basadas en la reacción en cadena de la polimerasa cuantitativa (RT-qPCR por sus siglas en inglés). Sin embargo, muchas economías emergentes han tenido problemas con las demandas actuales de pruebas moleculares debido a limitaciones económicas, técnicas y tecnológicas. Objetivo: Definir un protocolo de diagnóstico potencial para aumentar la capacidad de prueba en las condiciones actuales y posteriores a la pandemia. Métodos: Revisamos la literatura, las patentes y las aplicaciones comerciales, en busca de alternativas. Resultados: Encontramos un buen potencial en muestras de saliva, inactivación viral y extracción rápida de ARN por calentamiento; el uso de una tecnología isotérmica como la amplificación isotérmica mediada por horquillas (LAMP, por sus siglas en inglés) y la visualización del resultado de la prueba a simple vista mediante colorimetría o turbidez en el tubo. Conclusiones: Las muestras de saliva con extracción rápida de ARN por calentamiento y LAMP colorimétrico son opciones prometedoras para países con limitaciones económicas y de infraestructura.

Application of a low-cost, specific, and sensitive loop-mediated isothermal amplification (LAMP) assay to detect Plasmodium falciparum imported from Africa.

BACKGROUND: Chinese citizens traveling abroad bring back imported malaria cases to China. Current malaria diagnostic tests, including microscopy and antigen-detecting rapid tests, cannot reliably detect low-density infections. To complement existing diagnostic methods, we aimed to develop a new loop-mediated isothermal amplification (LAMP) assay to detect and identify Plasmodium falciparum in Chinese travelers returning from Africa. METHODS: We developed a miniaturized LAMP assay to amplify the actin I gene of P. falciparum. Each reaction consumed only 25% of the reagents used in a conventional LAMP assay and the same amount of DNA templates used in nested PCR. We evaluated this LAMP assay's performance and compared it to microscopy and a nested PCR assay using 466 suspected malaria cases imported from Africa. We assessed the sensitivity of the new LAMP assay using cultured P. falciparum, clinical samples, and a plasmid construct, allowing unprecedented precision when quantifying the limit of detection. RESULTS: The new LAMP assay was highly sensitive and detected two more malaria cases than nested PCR. Compared to nested PCR, the sensitivity and specificity of the novel LAMP assay were 100% [95% confidence interval (CI) 98.5-100%] and 99.1% (95% CI 96.7-99.9%), respectively. When evaluated using serial dilutions of the plasmid construct, the detection limit of the new LAMP was as low as 102 copies/µL, 10-fold lower than PCR. The LAMP assay detected 0.01 parasites/µL of blood (equal to 0.04 parasites/µL of DNA) using cultured P. falciparum and 1-7 parasites/µL of blood (4-28 parasites/µL of DNA) in clinical samples, which is as good as or better than previously reported and commercially licensed assays. CONCLUSION: The novel LAMP assay based on the P. falciparum actin I gene was specific, sensitive, and cost-effective, as it consumes 1/4 of the reagents in a typical LAMP reaction.

Ferrobotic swarms enable accessible and adaptable automated viral testing.

Expanding our global testing capacity is critical to preventing and containing pandemics1-9. Accordingly, accessible and adaptable automated platforms that in decentralized settings perform nucleic acid amplification tests resource-efficiently are required10-14. Pooled testing can be extremely efficient if the pooling strategy is based on local viral prevalence15-20; however, it requires automation, small sample volume handling and feedback not available in current bulky, capital-intensive liquid handling technologies21-29. Here we use a swarm of millimetre-sized magnets as mobile robotic agents ('ferrobots') for precise and robust handling of magnetized sample droplets and high-fidelity delivery of flexible workflows based on nucleic acid amplification tests to overcome these limitations. Within a palm-sized printed circuit board-based programmable platform, we demonstrated the myriad of laboratory-equivalent operations involved in pooled testing. These operations were guided by an introduced square matrix pooled testing algorithm to identify the samples from infected patients, while maximizing the testing efficiency. We applied this automated technology for the loop-mediated isothermal amplification and detection of the SARS-CoV-2 virus in clinical samples, in which the test results completely matched those obtained off-chip. This technology is easily manufacturable and distributable, and its adoption for viral testing could lead to a 10-300-fold reduction in reagent costs (depending on the viral prevalence) and three orders of magnitude reduction in instrumentation cost. Therefore, it is a promising solution to expand our testing capacity for pandemic preparedness and to reimagine the automated clinical laboratory of the future.

BD MAX Enteric Bacterial, Bacterial Plus, and Virus Panels for Diagnosis of Acute Infectious Gastroenteritis: a Cost-Benefit Analysis.

Economic assessment is required to gauge the value of implementing PCR syndromic platforms in the microbiology laboratory for the diagnosis of community-acquired acute gastroenteritis (AGE) in pediatric and adult in- and outpatients. A cost-benefit analysis was conducted from a health care system perspective using BD MAX Enteric Bacterial, Bacterial Plus, and Virus panels. Two 6-month periods were selected, in which either conventional procedures (in 2017) or BD MAX PCR multiplex panels (in 2018) were used. We retrospectively reviewed medical records of all patients with positive results and a representative sample of negative ones. A Markov model was used to represent transition probabilities between different health care states from time of stool microbiological study until completion of AGE-episode-associated health care. A total of 1,336 medical records were reviewed (829 in 2018 and 507 in 2017), showing overall a significantly higher positivity rate in 2018 than in 2017 (26% versus 6%, P < 0.001). The total cost per individual associated with health care for AGE was €314 in 2018 and €341 in 2017; when we only considered the pediatric cohort, the figures were €271 and €456, respectively. Using Tornado sensitivity analyses, we found that the three variables that most influenced the model in descending order of weight were the probability of longer hospital stays, the probability of returning to the emergency room (ER), and the probability of hospitalization from the ER. Use of BD MAX enteric PCR platforms for the diagnosis of community-acquired AGE instead of a non-PCR-based conventional approach results in an incremental benefit from a health care perspective in the general population, particularly children. IMPORTANCE The implementation of multiplex molecular panels allows microbiological laboratories to quickly, sensitively, and accurately diagnose acute infectious gastroenteritis. This methodology therefore allows faster decisions regarding treatment and infection control measures. Economic evaluations are required to gauge the value of implementing these syndromic PCR platforms in a community-based acute gastroenteritis setting. We studied the potential clinical and cost benefits, in terms of both their impact on laboratory costs and the subsequent costs of managing patients.

Performance of PCR-based syndromic testing compared to bacterial culture in patients with suspected pneumonia applying microscopy for quality assessment.

Syndromic testing for lower respiratory tract infections with BioFire® FilmArray® Pneumonia Panel Plus (BF) detects 27 pathogens with a turn-around-time of one hour. We compared the performance of BF with culture. Samples from 298 hospitalized patients with suspected pneumonia routinely sent for culture were also analyzed using BF. Retrospectively, patients were clinically categorized as having "pneumonia" or "no pneumonia." BF and culture were compared by analytical performance, which was evaluated by pathogen concordance, and by clinical performance by comparing pathogen detections in patients with and without pneumonia. The BF results for viruses and atypical bacteria were not included in the performance analysis. In 298 patient samples, BF and culture detected 285 and 142 potential pathogens, respectively. Positive percent agreement (PPA) was 88% (125/142). In patients with community-acquired pneumonia (CAP), clinical sensitivity was 70% and 51%, and specificity was 43% and 71% for BF and culture, respectively. In patients with hospital-acquired pneumonia, the corresponding numbers were 55% and 23%, and 47% and 68%. There was no significant improvement of performance, when only high-quality sputum samples were considered. Efficacy of both BF and culture was low. Both tests are best used in CAP patients for whom the diagnosis has already been clinically established. Indiscriminate use may be clinically misleading and a cause of improper use of antibiotics.

A rapid, specific, extraction-less, and cost-effective RT-LAMP test for the detection of SARS-CoV-2 in clinical specimens.

In 2019 a newly identified coronavirus, designated as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread rapidly from the epicenter in Wuhan (China) to more than 150 countries around the world, causing the Coronavirus disease 2019 (COVID-19) pandemic. In this study, we describe an extraction-less method based on reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) intended for the rapid qualitative detection of nucleic acid from SARS-CoV-2 in upper respiratory specimens, including oropharyngeal and nasopharyngeal swabs, anterior nasal and mid-turbinate nasal swabs, nasopharyngeal washes/aspirates or nasal aspirates as well as bronchoalveolar lavage (BAL) from individuals suspected of COVID-19 by their healthcare provider. The assay's performance was evaluated and compared to an RT quantitative PCR-based assay (FDA-approved). With high sensitivity, specificity, and bypassing the need for RNA extraction, the RT-LAMP Rapid Detection assay is a valuable and fast test for an accurate and rapid RNA detection of the SARS-CoV-2 virus and potentially other pathogens. Additionally, the versatility of this test allows its application in virtually every laboratory setting and remote location where access to expensive laboratory equipment is a limiting factor for testing during pandemic crises.

Performance Assessment of a Rapid Molecular Respiratory Syncytial Virus Point-of-Care Test: A Prospective Community Study in Older Adults.

BACKGROUND: Respiratory syncytial virus (RSV) causes a substantial burden in older adults. Viral load in RSV-infected adults is generally lower compared to young children, which could result in suboptimal sensitivity of RSV diagnostics. Although the Xpert® Xpress Flu/RSV assay has been used in routine clinical care, its sensitivity to diagnose RSV infection in older adults is largely unknown. We aimed to compare the performance of the Xpert® Xpress Flu/RSV assay with real-time reverse-transcription polymerase chain reaction (RT-PCR) in home-dwelling older adults (≥60 years of age). METHODS: Nasopharyngeal swabs were tested with Xpert® Xpress Flu/RSV and compared to RSV RT-PCR in older adults with acute respiratory tract infections with different levels of disease severity. RESULTS: We studied 758 respiratory samples from 561 older adults from 2 consecutive RSV seasons. Thirty-five (4.6%) samples tested positive for RSV by at least 1 of the assays, of which 2 samples were negative by Xpert® Xpress Flu/RSV and 3 samples by real-time RT-PCR. The positive percentage agreement (PPA) was 90.9% (95% confidence interval [CI], 76.4%-96.8%) and negative percentage agreement was 99.7% (95% CI, 99.0%-99.9%). Viral loads were low (≤103 copies/mL or cycle threshold value ≥34) in all cases with discordant results for the 2 assays. CONCLUSIONS: The PPA of Xpert® Xpress Flu/RSV compared to routine RT-PCR is high for RSV detection in home-dwelling older adults. The assay is fast and easy to use at the point of care. CLINICAL TRIALS REGISTRATION: NCT03621930.

End-to-end system for rapid and sensitive early-detection of SARS-CoV-2 for resource-poor and field-test environments using a $51 lab-in-a-backpack.

COVID-19 has exposed stark inequalities between resource-rich and resource-poor countries. International UN- and WHO-led efforts, such as COVAX, have provided SARS-CoV-2 vaccines but half of African countries have less than 2% vaccinated in their population, and only 15 have reached 10% by October 2021, further disadvantaging local economic recovery. Key for this implementation and preventing further mutation and spread is the frequency of voluntary [asymptomatic] testing. It is limited by expensive PCR and LAMP tests, uncomfortable probes deep in the throat or nose, and the availability of hardware to administer in remote locations. There is an urgent need for an inexpensive "end-to-end" system to deliver sensitive and reliable, non-invasive tests in resource-poor and field-test conditions. We introduce a non-invasive saliva-based LAMP colorimetric test kit and a $51 lab-in-a-backpack system that detects as few as 4 viral RNA copies per µL. It consists of eight chemicals, a thermometer, a thermos bottle, two micropipettes and a 1000-4000 rcf electronically operated centrifuge made from recycled computer hard drives (CentriDrive). The centrifuge includes a 3D-printed rotor and a 12 V rechargeable Li-ion battery, and its 12 V standard also allows wiring directly to automobile batteries, to enable field-use of this and other tests in low infrastructure settings. The test takes 90 minutes to process 6 samples and has reagent costs of $3.5 per sample. The non-invasive nature of saliva testing would allow higher penetration of testing and wider adoption of the test across cultures and settings (including refugee camps and disaster zones). The attached graphical procedure would make the test suitable for self-testing at home, performing it in the field, or in mobile testing centers by minimally trained staff.

Cost analysis of reflexive versus selective molecular testing for indeterminate thyroid nodules.

BACKGROUND: Molecular testing is now commonly used to refine the diagnosis of indeterminate thyroid nodules. The purpose of this study is to compare the costs of a reflexive molecular testing strategy to a selective testing strategy for indeterminate thyroid nodules. METHODS: A Markov model was constructed to estimate the annual cost of diagnosis and treatment of a real-world cohort of patients with cytologically indeterminate thyroid nodules, comparing a reflexive testing strategy to a selective testing strategy. Model variables were abstracted from institutional clinical trial data, literature review, and the Medicare physician fee schedule. RESULTS: The average cost per patient in the reflexive testing strategy was $8,045, compared with $6,090 in the selective testing strategy. In 10,000 Monte Carlo simulations, diagnostic thyroid lobectomy for benign nodules was performed in 2,440 patients in the reflexive testing arm, compared with 3,389 patients in the selective testing arm, and unintentional observation for malignant nodules occurred in 479 patients in the reflexive testing arm, compared with 772 patients in the selective testing arm. The cost of molecular testing had the greatest impact on overall costs, with $1,050 representing the cost below which the reflexive testing strategy was cost saving compared with the selective testing strategy. CONCLUSION: In this cost-modeling study, reflexive molecular testing for indeterminate thyroid nodules enabled patients to avoid unnecessary thyroid lobectomy at an estimated cost of $20,600 per surgery avoided.

Saving lives through early diagnosis: the promise and role of point of care testing for sickle cell disease.

Sickle cell disease (SCD) is a devastating and under-recognised global child health issue affecting over 300,000 infants annually, with the highest prevalence in India and sub-Saharan Africa. Most affected infants born in low- and middle-income countries (LMIC) lack access to SCD testing and die from complications in the first years of life without a formal diagnosis. The majority of deaths are preventable with early diagnosis and provision of inexpensive interventions. Despite global recognition of the urgent need, expansion of SCD newborn screening (NBS) programmes beyond the pilot stage has been obstructed by a dependence on an expensive and logistically challenging centralised laboratory testing model. Recently, several point-of-care tests (POCT) for SCD have been developed with promising field validation studies. Here, we summarise the state of POCT for SCD, review barriers and unanswered questions, and discuss optimal strategies for utilising POCT to address the growing global burden of SCD. There is an urgent need to prospectively evaluate the ability of POCT to reduce the morbidity and high early mortality of SCD. To impact a sustainable reduction to this end, it is essential to link a diagnosis with comprehensive SCD care, including wide and affordable access to affordable hydroxycarbamide therapy.