Advances in the Rapid Diagnostic of Viral Respiratory Tract Infections

Diagnostic tools in respiratory medicine (Review)

Recent advancements in diagnostic technologies have significantly transformed the landscape of respiratory medicine, aiming for early detection, improved specificity and personalized therapeutic strategies. Innovations in imaging such as multi-slice computed tomography (CT) scanners, high-resolution CT and magnetic resonance imaging (MRI) have revolutionized our ability to visualize and assess the structural and functional aspects of the respiratory system. These techniques are complemented by breakthroughs in molecular biology that have identified specific biomarkers and genetic determinants of respiratory diseases, enabling targeted diagnostic approaches. Additionally, functional tests including spirometry and exercise testing continue to provide valuable insights into pulmonary function and capacity. The integration of artificial intelligence is poised to further refine these diagnostic tools, enhancing their accuracy and efficiency. The present narrative review explores these developments and their impact on the management and outcomes of respiratory conditions, underscoring the ongoing shift towards more precise and less invasive diagnostic modalities in respiratory medicine.

Rapid microbiological respiratory point-of-care testing: a qualitative study with primary care clinicians

BACKGROUND

Rapid microbiological point-of-care tests (RM POCTs) present an opportunity to reduce antibiotic exposure and antimicrobial resistance (AMR). So far, there is limited understanding of how RM POCTs may support clinicians in primary care in the UK and how RM POCTs might be integrated into practice.

AIM

To investigate clinicians' views on how RM POCTs can influence clinical decisions and routine practice, and perspectives on how RM POCTs can impact the clinician-patient relationship.

DESIGN AND SETTING

A qualitative study was undertaken. The study was embedded in a multi-centre, individually randomised controlled efficacy trial, which evaluated the use of a multiplex RM POCT for suspected respiratory tract infections (RTIs) in primary care.

METHOD

Individual interviews were conducted with 18 clinicians (GPs, n = 9; advanced nurse practitioners, n = 4; paramedics, n = 2; trainee advanced nurse practitioner, n = 1; clinical pharmacist, n = 1; and emergency care practitioner, n = 1). Interviews were audio-recorded, transcribed verbatim, and analysed thematically informed by a realist approach.

RESULTS

RM POCTs can guide prescribing decisions when clinicians experience diagnostic uncertainty and support communication with patients to reinforce prescribing decisions. Consequently, the perceived value of, and use of, RM POCTs varied according to clinicians' confidence in making prescribing decisions and managing patient expectations and their clinical roles. The costly and time-consuming nature of RM POCTs meant that integration of the tests into routine practice was considered unlikely at present.

CONCLUSION

The findings from this study highlight the potential benefits and challenges of integrating RM POCTs into routine practice. Clinicians in this study had generally favourable views towards RM POCTs. However, further RM POCT training, complementary strategies, such as communication skills training and patient education, and clear guidance on implementation should be explored to optimise RM POCT feasibility and outcomes across different primary care settings.

Advances and Challenges in Antiviral Development for Respiratory Viruses

The development of antivirals for respiratory viruses has advanced markedly in response to the growing threat of pathogens such as Influenzavirus (IAV), respiratory syncytial virus (RSV), and SARS-CoV-2. This article reviews the advances and challenges in this field, highlighting therapeutic strategies that target critical stages of the viral replication cycle, including inhibitors of viral entry, replication, and assembly. In addition, innovative approaches such as inhibiting host cellular proteins to reduce viral resistance and repurposing existing drugs are explored, using advanced bioinformatics tools that optimize the identification of antiviral candidates. The analysis also covers emerging technologies such as nanomedicine and CRISPR gene editing, which promise to improve the stability and efficacy of treatments. While current antivirals offer valuable options, they face challenges such as viral evolution and the need for accessible treatments for vulnerable populations. This article underscores the importance of continued innovation in biotechnology to overcome these limitations and provide safe and effective treatments. Combining traditional and advanced approaches in developing antivirals is essential in order to address respiratory viral diseases that affect global health.

Recommendations on Rapid Diagnostic Point-of-care Molecular Tests for Respiratory Infections in the United Arab Emirates

Traditional testing methods in the Middle East Region, including the United Arab Emirates (UAE), particularly the testing of Respiratory Syncytial Virus (RSV), influenza, group A streptococcus (GAS), and COVID-19 have the potential to be upgraded to new and advanced diagnostics methods that improve lead time to diagnosis, consumption of healthcare resources and patient experience. In addition, based on the research, it was reported that there is an underreporting of respiratory cases, overuse of antibiotics, and prolonged hospitalizations which is posing pressure on UAE healthcare stakeholders. A literature review was done exploring UAE's current diagnostic practices, recommended guidelines, diagnostic gaps, and challenges in RSV, GAS, Influenza, and COVID-19. This was followed by stakeholder discussions focusing on assessing current diagnostic practices, usage of rapid molecular point-of-care (POC) diagnostic tests, current gaps in diagnosis, targeted profiles for POC testing, and potential impact on patient management for targeted respiratory infections. A round table discussion with healthcare experts, insurance experts, key opinion leaders, and pulmonologists discussed challenges and opportunities in treating respiratory diseases. UAE healthcare stakeholders suggest that introducing alternative and up-to-date diagnostic methods such as POC molecular testing is expected to improve healthcare outcomes, optimize resources, and develop a robust case management of respiratory tract infections. It is essential to emphasize that by introducing POC testing, precision medicine is reinforced, efficiency is achieved, and the overall management of population health is enhanced.

Transforming respiratory tract infection diagnosis in the kingdom of saudi arabia through point-of-care testing: A white paper for policy makers

With the evident increased prevalence of respiratory tract infections (RTIs) such as Respiratory Syncytial Virus (RSV), influenza, Group A Streptococcus (GAS), and COVID-19, the conventional diagnostic methods are considered sub-optimal in providing timely management to patients in the Kingdom of Saudi Arabia (KSA). Gaps in current diagnostics are magnified by the Kingdom's unique demographic composition, comprising 11.9 million foreign workers, and the annual influx of over 10 million pilgrims. Current gaps in timely diagnosis leads to delays in treatment, misuse of antibiotics, and protracted hospital stays, subsequently compromising patient care, and escalating healthcare costs. KSA healthcare stakeholders suggest that the integration of rapid molecular Point-of-Care Testing (POCT) into the Kingdom's healthcare infrastructure is an absolute necessity. This publication serves as an urgent call for action aimed at healthcare policymakers in Saudi Arabia, to review the existing diagnostic challenges and include rapid POCTs in the Saudi healthcare strategy for respiratory infections.

Focused ion beam-fabricated nanorod substrate for label-free surface-enhanced Raman spectroscopy and enabling dual virus detection

The COVID-19 pandemic presents global challenges, notably with co-infections in respiratory tract involving SARS-CoV-2 variants and influenza strains. Detecting multiple viruses simultaneously is crucial for accurate diagnosis, effective tracking infectious sources, and containment of the epidemic. This study uses a label-free surface-enhanced Raman spectroscopy (SERS) method using Au NPs/pZrO2 (250) and FIB-made Au NRs (100) to detect dual viruses, including SARS-CoV-2 Delta variant (D) and influenza A (A) or B (B) virus. Results demonstrate distinct peaks facilitating virus differentiation, especially between D and A or B, with clear disparities between substrates; specific peaks at 950 and 1337 cm-1 are pivotal for discerning viruses using Au NPs/pZrO2 (250), while those at 1050, 1394, and 1450 cm-1 and 1033, 1165, 1337, and 1378 cm-1 are key for validation using Au NRs (100). Differences in substrate surface morphology and spatial disposition of accommodating viruses significantly influence hotspot formation and Raman signal amplification efficiency, thereby affecting the ability to distinguish various viruses. Furthermore, both substrates offer insights, even in the presence of oxymetazoline hydrochloride (an interfering substance), with practical implications in viral diagnosis. The customized design and reproducibility underscore efficient Raman signal amplification, even in challenging environments, highlighting potential for widespread virus detection.

Disease burden and high-risk populations for complications in patients with acute respiratory infections: a scoping review

Background

Acute respiratory infections (ARIs) represent a significant public health concern in the U.S. This study aimed to describe the disease burden of ARIs and identify U.S. populations at high risk of developing complications.

Methods

This scoping review searched PubMed and EBSCO databases to analyze U.S. studies from 2013 to 2022, focusing on disease burden, complications, and high-risk populations associated with ARIs.

Results

The study included 60 studies and showed that ARI is associated with a significant disease burden and healthcare resource utilization (HRU). In 2019, respiratory infection and tuberculosis caused 339,703 cases per 100,000 people, with most cases being upper respiratory infections and most deaths being lower respiratory infections. ARI is responsible for millions of outpatient visits, especially for influenza and pneumococcal pneumonia, and indirect costs of billions of dollars. ARI is caused by multiple pathogens and poses a significant burden on hospitalizations and outpatient visits. Risk factors for HRU associated with ARI include age, chronic conditions, and socioeconomic factors.

Conclusion

The review underscores the substantial disease burden of ARIs and the influence of age, chronic conditions, and socioeconomic status on developing complications. It highlights the necessity for targeted strategies for high-risk populations and effective pathogen detection to prevent severe complications and reduce HRU.

Fast detection of bacterial gut pathogens on miniaturized devices: an overview

INTRODUCTION

Gut microbes pose challenges like colon inflammation, deadly diarrhea, antimicrobial resistance dissemination, and chronic disease onset. Development of early, rapid and specific diagnosis tools is essential for improving infection control. Point-of-care testing (POCT) systems offer rapid, sensitive, low-cost and sample-to-answer methods for microbe detection from various clinical and environmental samples, bringing the advantages of portability, automation, and simple operation.

AREAS COVERED

Rapid detection of gut microbes can be done using a wide array of techniques including biosensors, immunological assays, electrochemical impedance spectroscopy, mass spectrometry and molecular biology. Inclusion of Internet of Things, machine learning, and smartphone-based point-of-care applications is an important aspect of POCT. In this review, the authors discuss various fast diagnostic platforms for gut pathogens and their main challenges.

EXPERT OPINION

Developing effective assays for microbe detection can be complex. Assay design must consider factors like target selection, real-time and multiplex detection, sample type, reagent stability and storage, primer/probe design, and optimizing reaction conditions for accuracy and sensitivity. Mitigating these challenges requires interdisciplinary collaboration among scientists, clinicians, engineers, and industry partners. Future efforts are essential to enhance sensitivity, specificity, and versatility of POCT systems for gut microbe detection and quantification, advancing infectious disease diagnostics and management.

Impact of bronchoalveolar lavage on the management of immunocompromised hosts

BACKGROUND

Respiratory infections are an important cause of morbidity and mortality in immunocompromised individuals. Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) is an important tool to detect infectious agents in immunocompromised patients with low respiratory tract infections (LRTI).

RESEARCH QUESTION

BAL changes the management of immunocompromised patients with suspected LRTI.

STUDY DESIGN AND METHODS

Immunocompromised patients with a suspicion of LRTI underwent diagnostic BAL. The primary composite outcome consisted of pre-defined modifications in the management of the immunocompromised patients following BAL. We quantified the impact of bronchoscopy up to 30 days after the procedure.

RESULTS

A total of 2666 visits from 1301 patients were included in the study and immunosuppression was classified as haematological (n = 1040; 544 patients), solid organ transplantation (n = 666; 107 patients) and other causes (n = 960; 650 patients). BAL led to a change in management in 52.36% (n = 1396) of all cases. This percentage, as well as the 30-day mortality differed significantly amongst the three groups. Age, C-reactive protein and aetiology of infection determined significantly the risk of 30-day mortality in all patients. In 1.89% (n = 50) of all cases, a combination of 2 respiratory viral agents was identified and 24.23% (n = 646) were diagnosed with a single respiratory viral agent.

INTERPRETATION

BAL leads to changes in management in the majority of immunosuppressed patients. There is a high prevalence of multimicrobial infections and respiratory viral infections in immunocompromised patients with respiratory symptoms. Individual virus infection is associated with diverse risk of a negative outcome.

Development of Photonic Multi-Sensing Systems Based on Molecular Gates Biorecognition and Plasmonic Sensors: The PHOTONGATE Project

This paper presents the concept of a novel adaptable sensing solution currently being developed under the EU Commission-founded PHOTONGATE project. This concept will allow for the quantification of multiple analytes of the same or different nature (chemicals, metals, bacteria, etc.) in a single test with levels of sensitivity and selectivity at/or over those offered by current solutions. PHOTONGATE relies on two core technologies: a biochemical technology (molecular gates), which will confer the specificity and, therefore, the capability to be adaptable to the analyte of interest, and which, combined with porous substrates, will increase the sensitivity, and a photonic technology based on localized surface plasmonic resonance (LSPR) structures that serve as transducers for light interaction. Both technologies are in the micron range, facilitating the integration of multiple sensors within a small area (mm2). The concept will be developed for its application in health diagnosis and food safety sectors. It is thought of as an easy-to-use modular concept, which will consist of the sensing module, mainly of a microfluidics cartridge that will house the photonic sensor, and a platform for fluidic handling, optical interrogation, and signal processing. The platform will include a new optical concept, which is fully European Union Made, avoiding optical fibers and expensive optical components.

Rapid diagnostics to enhance therapy selection for the treatment of bacterial infections

Purpose of review

Rapid diagnostic tests (RDTs) may reduce morbidity and mortality related to bacterial infections by reducing time to identification of pathogens and antibiotic resistance mechanisms. There has been a significant increase in the breadth and depth of available technology utilized by RDTs.

Recent findings

There are numerous Food and Drug Administration (FDA)-cleared assays for rapid detection of bacteria from various specimen types from sites including blood, stool, central nervous system and respiratory tract. Most RDTs currently FDA-cleared are molecular tests designed as syndromic panels that provide identification of on-panel organisms and resistance genes. One FDA-cleared rapid phenotypic assay for antimicrobial susceptibility testing is currently available and others are in development. Studies of these technologies' clinical impact consistently demonstrate improvements in clinical care processes such as time to de-escalation and escalation of antibiotic therapy particularly for blood and respiratory specimen tests. Other RDTs show inconsistent impact on antibiotic use. Antimicrobial stewardship programs are vital to ensure the greatest benefit from RDTs in clinical practice.

Summary

The advancement and implementation of RDTs, in conjunction with antimicrobial stewardship, to enhance treatment selection for bacterial infections should be regarded as a core element to improve clinical outcomes for patients. Although challenges exist in the use of RDTs, there is a need for continued innovation in technology, implementation science and collaboration across clinical professions to optimize care.

The Clinical Laboratory Is an Integral Component to Health Care Delivery : An Expanded Representation of the Total Testing Process

OBJECTIVES

Developing an expanded representation of the total testing process that includes contemporary elements of laboratory practice can be useful to understanding and optimizing testing workflows across clinical laboratory and patient care settings.

METHODS

Published literature and meeting reports were used by the coauthors to inform the development of the expanded representation of the total testing process and relevant examples describing its uses.

RESULTS

A visual representation of the total testing process was developed and contextualized to patient care scenarios using a number of examples covering the detection of blood culture contamination, use of next-generation sequencing, and pharmacogenetic testing.

CONCLUSIONS

The expanded representation of the total testing process can serve as a model and framework to document and improve the use of clinical testing within the broader context of health care delivery. This representation recognizes increased engagement among clinical laboratory professionals with patients and other health care providers as essential to making informed decisions. The increasing use of data is highlighted as important to ensuring quality, appropriate test utilization, and sustaining an efficient workflow across clinical laboratory and patient care settings. Maintaining a properly resourced and competent workforce is also featured as an essential component to the testing process.

Clinical performance evaluation of the Fluorecare® SARS-CoV-2 & Influenza A/B & RSV rapid antigen combo test in symptomatic individuals

BACKGROUND

A SARS-CoV-2+Flu A/B+RSV Combo Rapid test may be more relevant than Rapid Antigen Diagnostic (RAD) tests targeting only SARS-CoV-2 since we are facing a concurrent circulation of these viruses during the winter season.

OBJECTIVES

To assess the clinical performance of a SARS-CoV-2+Flu A/B+RSV Combo test in comparison to a multiplex RT-qPCR.

STUDY DESIGN

Residual nasopharyngeal swabs issued from 178 patients were included. All patients, adults and children, were symptomatic and presented at the emergency department with flu-like symptoms. Characterization of the infectious viral agent was done by RT-qPCR. The viral load was expressed as cycle threshold (Ct). Samples were then tested using the multiplex RAD test Fluorecare^®ฏ SARS-CoV-2 & Influenza A/B & RSV Antigen Combo Test. Data analysis was carried out using descriptive statistics.

RESULTS

The sensitivity of the test varies according to the virus, with the highest sensitivity observed for Influenza A (80.8.% [95%CI: 67.2 - 94.4]) and the lowest sensitivity observed for RSV (41.5% [95%CI: 26.2 - 56.8]). Higher sensitivities were observed for samples with high viral loads (Ct < 20) and decrease with low viral loads. The specificity for SARS-CoV-2, RSV and Influenza A and B was >95%.

CONCLUSIONS

The Fluorecare® combo antigenic presents satisfying performance in real-life clinical setting for Influenza A and B in samples with high viral load. This could be useful to allow a rapid (self-)isolation as the transmissibility of these viruses increase with the viral load. According to our results, its use to rule-out SARS-CoV-2 and RSV infection is not sufficient.

Conductive Thread-Based Immunosensor for Pandemic Influenza A (H1N1) Virus Detection

Infectious agents such as viruses pose significant threats to human health, being transmitted via direct contact as well as airborne transmission without direct contact, thus requiring rapid detection to prevent the spread of infectious diseases. In this study, we developed a conductive thread-based immunosensor (CT-IS), a biosensor to easily detect the presence of airborne viruses. CT-IS utilizes an antibody that specifically recognizes the HA protein of the pandemic influenza A (pH1N1) virus, which is incorporated into the conductive thread. The antigen-antibody interaction results in increased strain on the conductive thread in the presence of the pH1N1 virus, resulting in increased electrical resistance of the CT-IS. We evaluated the performance of this sensor using the HA protein and the pH1N1 virus, in addition to samples from patients infected with the pH1N1 virus. We observed a significant change in resistance in the pH1N1-infected patient samples (positive: n = 11, negative: n = 9), whereas negligible change was observed in the control samples (patients not infected with the pH1N1 virus; negative). Hence, the CT-IS is a lightweight fiber-type sensor that can be used as a wearable biosensor by combining it with textiles, to detect the pH1N1 virus in a person's vicinity.

Usefulness of Combining Sputum and Nasopharyngeal Samples for Viral Detection by Reverse Transcriptase PCR in Adults Hospitalized with Acute Respiratory Illness

Nasopharyngeal swabs (NPS) or washings have traditionally been used to diagnose respiratory tract infections. Reverse transcriptase PCR (RT-PCR) is widely used for rapid viral detection using samples from the upper respiratory tract. However, RT-PCR is rarely applied to sputum samples, mainly due to the viscosity of sputum. Thus, we assessed the detection rates of respiratory viruses from NPS, sputum samples, and combined NPS and sputum samples using multiplex RT-PCR (Allplex respiratory panels I, II, and III; Seegene, Seoul, South Korea). Paired NPS and sputum samples were collected from 219 patients admitted to the hospital with acute respiratory illnesses from October to December 2019. RT-PCR was performed on each sample for virus detection. Combined samples for virus detection were produced using remnant NPS and sputum samples with a positive virus signal. Respiratory viral nucleic acid was identified in 92 (42%) of 219 patients. Among the 92 viral detections, 61 (28%) were detected by both NPS and sputum samples. Twenty-four (11%) were sputum positive/NPS negative, and seven (3%) were sputum negative/NPS positive. For the combined NPS-sputum samples (n = 92), all paired samples positive in both specimens (n = 61) were also positive in the combined NPS-sputum sample. Twenty-seven (87%) of the 31 discordant paired samples were positive in the combined samples. Out of the total of 103 viruses identified before combining the samples, the detection rate of the combined samples was 94% (97/103), which was higher than the detection rates of sputum (88%; 91/103) and NPS (71%; 73/103). Because additional tests incur additional costs, our findings suggest that combining samples instead of testing separate samples using RT-PCR is likely the most cost-effective method of viral testing for patients with acute respiratory illnesses. IMPORTANCE This study reveals that RT-PCR utilizing sputum significantly increased the detection rate for respiratory viral nucleic acids among adult patients admitted to the hospital, compared to nasopharyngeal swabs (NPS). Notably, combined samples of sputum and NPS maintained the majority of the improved sputum detection rate with only a few positive signal losses from NPS samples. In order to detect respiratory viruses in adult patients with acute respiratory illness, it is important to choose the optimal respiratory samples. This study helped to improve our understanding of this process.

A Digital Microfluidic RT-qPCR Platform for Multiple Detections of Respiratory Pathogens

The coronavirus disease 2019 pandemic has spread worldwide and caused more than six million deaths globally. Therefore, a timely and accurate diagnosis method is of pivotal importance for controlling the dissemination and expansions. Nucleic acid detection by the reverse transcription-polymerase chain reaction (RT-PCR) method generally requires centralized diagnosis laboratories and skilled operators, significantly restricting its use in rural areas and field settings. The digital microfluidic (DMF) technique provides a better option for simultaneous detections of multiple pathogens with fewer specimens and easy operation. In this study, we developed a novel digital microfluidic RT-qPCR platform for multiple detections of respiratory pathogens. This method can simultaneously detect eleven respiratory pathogens, namely, mycoplasma pneumoniae (MP), chlamydophila pneumoniae (CP), streptococcus pneumoniae (SP), human respiratory syncytial virus A (RSVA), human adenovirus (ADV), human coronavirus (HKU1), human coronavirus 229E (HCoV-229E), human metapneumovirus (HMPV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus (FLUA) and influenza B virus (FLUB). The diagnostic performance was evaluated using positive plasmids samples and clinical specimens compared with off-chip individual RT-PCR testing. The results showed that the limit of detections was around 12 to 150 copies per test. The true positive rate, true negative rate, positive predictive value, negative predictive value, and accuracy of DMF on-chip method were 93.33%, 100%, 100%, 99.56%, and 99.85%, respectively, as validated by the off-chip RT-qPCR counterpart. Collectively, this study reported a cost-effective, high sensitivity and specificity on-chip DMF RT-qPCR system for detecting multiple respiratory pathogens, which will greatly contribute to timely and effective clinical management of respiratory infections in medical resource-limited settings.

COVID-19 Update: The Golden Time Window for Pharmacological Treatments and Low Dose Radiation Therapy

At the beginning of the COVID-19 emergence, many scientists believed that, thanks to the proofreading enzyme of SARS-CoV-2, the virus would not have many mutations. Our team introduced the concept of radiation at extremely low doses in an attempt to establish selected pressure-free treatment approaches for COVID-19. The capacity of low-dose radiation to modulate excessive inflammatory responses, optimize the immune system, prevent the occurrence of dangerous cytokine storm, regulate lymphocyte counts, and control bacterial co-infections as well as different modalities were proposed as a treatment program for patients with severe COVID-19-associated pneumonia. There is now substantial evidence which indicates that it would be unwise not to further investigate low-dose radiation therapy (LDRT) as an effective remedy against COVID-19-associated pneumonia.

Early Notice Pointer, an IoT-like Platform for Point-of-Care Feet and Body Balance Screening

Improper foot biomechanics associated with uneven bodyweight distribution contribute to impaired balance and fall risks. There is a need to complete the panel of commercially available devices for the self-measurement of BMI, fat, muscle, bone, weight, and hydration with one that measures weight-shifting at home as a pre-specialist assessment system. This paper reports the development of the Early Notice Pointer (ENP), a user-friendly screening device based on weighing scale technology. The ENP is designed to be used at home to provide a graphic indication and customised and evidence-based foot and posture triage. The device electronically detects and maps the bodyweight and distinct load distributions on the main areas of the feet: forefoot and rearfoot. The developed platform also presents features that assess the user's balance, and the results are displayed as a simple numerical report and map. The technology supports data display on mobile phones and accommodates multiple measurements for monitoring. Therefore, the evaluation could be done at non-specialist and professional levels. The system has been tested to validate its accuracy, precision, and consistency. A parallel study to describe the frequency of arch types and metatarsal pressure in young adults (1034 healthy subjects) was conducted to explain the importance of self-monitoring at home for better prevention of foot arch- and posture-related conditions. The results showed the potential of the newly created platform as a screening device ready to be wirelessly connected with mobile phones and the internet for remote and personalised identification and monitoring of foot- and body balance-related conditions. The real-time interpretation of the reported physiological parameters opens new avenues toward IoT-like on-body monitoring of human physiological signals through easy-to-use devices on flexible substrates for specific versatility.