Use of the FebriDx® host-response point-of-care test may reduce antibiotic use for respiratory tract infections in primary care: a mixed-methods feasibility study.

INTRODUCTION: FebriDx® is a CE-marked, single-use point-of-care test with markers for bacterial [C-reactive protein (CRP)] and viral [myxovirus resistance protein A (MxA)] infection, using finger-prick blood samples. Results are available after 10-12 min. We explored the usability and potential impact of FebriDx® in reducing antibiotic prescriptions for lower respiratory tract infection (LRTI) in primary care, and the feasibility of conducting a randomized controlled trial (RCT). METHODS: Patients (aged ≥1 year) with LRTI deemed likely to receive antibiotic prescription were recruited at nine general practices and underwent FebriDx® testing. Data collection included FebriDx® results, antibiotic prescribing plan (before and after testing) and re-consultation rates. Staff completed System Usability Scale questionnaires. RESULTS: From 31 January 2023 to 9 June 2023, 162 participants participated (median age 57 years), with a median symptom duration of 7 days (IQR 5-14). A valid FebriDx® result was obtained in 97% (157/162). Of 155 patients with available results, 103 (66%) had no detectable CRP or MxA, 28 (18%) had CRP only, 5 (3%) had MxA only, and 19 (12%) had both CRP and MxA. The clinicians' stated management plan was to prescribe antibiotics for 86% (134/155) before testing and 45% (69/155) after testing, meaning a 41% (95% CI: 31%, 51%) difference after testing, without evidence of increased re-consultation rates. Ease-of-use questionnaires showed 'good' user-friendliness. CONCLUSIONS: Use of FebriDx® to guide antibiotic prescribing for LRTI in primary care was associated with a substantial reduction in prescribing intentions. These results support a fully powered RCT to confirm its impact and safety.

Use of the FebriDx® point-of-care-test for lower respiratory tract infections in primary care: a qualitative interview study.

BACKGROUND: FebriDx® is a single-use, analyser-free, point-of-care test with markers for bacterial (C-reactive protein [CRP]) and viral (myxovirus resistance protein A [MxA]) infection, measured on a finger-prick blood sample. AIM: As part of a larger feasibility study, we explored the views of healthcare professionals (HCPs) and patients on the use of FebriDx® to safely reduce antibiotic prescriptions for lower respiratory tract infections (LRTI) in primary care. DESIGN & SETTING: Remote semi-structured qualitative interviews METHOD: 22 participants (12 patients who underwent FebriDx® testing and 10 HCPs from general practices who conducted testing) participated in interviews which were analysed thematically. RESULTS: Patients' and HCPs' express positive views about use of the test. They felt FebriDx was a useful tool to inform prescribing decisions and provided a visual aid to support shared decision-making and appropriate antibiotic use. Most felt it would be feasible to integrate use into routine primary care consultations. Some practical difficulties with blood collection and interpreting results which impacted on usability were identified. Some patients' reactions to negative test results suggested the need for better communication alongside use of the test. CONCLUSION: FebriDx® was perceived as a useful tool to guide antibiotic prescribing and support shared decision making. Initial practical problems with testing and communicating results are potential barriers to use. Training and practice on using the test and effective communication are likely to be important elements in ensuring patient understanding and satisfaction and successful adoption.

Clinical Outcomes of Rapid Respiratory Virus Testing in Emergency Departments: A Systematic Review and Meta-Analysis.

Importance: Rapid tests for respiratory viruses, including multiplex panels, are increasingly available in emergency departments (EDs). Their association with patient outcomes remains unclear. Objective: To determine if ED rapid respiratory virus testing in patients with suspected acute respiratory infection (ARI) was associated with decreased antibiotic use, ancillary tests, ED length of stay, and ED return visits and hospitalization and increased influenza antiviral treatment. Data Sources: Ovid MEDLINE, Embase (Ovid), Scopus, and Web of Science from 1985 to November 14, 2022. Study Selection: Randomized clinical trials of patients of any age with ARI in an ED. The primary intervention was rapid viral testing. Data Extraction and Synthesis: Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines were followed. Two independent reviewers (T.S. and K.W.) extracted data and assessed risk of bias using the Cochrane Risk of Bias, version 2.0. Estimates were pooled using random-effects models. Quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations framework. Main Outcomes and Measures: Antibiotic use and secondary outcomes were pooled separately as risk ratios (RRs) and risk difference estimates with 95% CIs. Results: Of 7157 studies identified, 11 (0.2%; n = 6068 patients) were included in pooled analyses. Routine rapid viral testing was not associated with antibiotic use (RR, 0.99; 95% CI, 0.93-1.05; high certainty) but was associated with higher use of influenza antivirals (RR, 1.33; 95% CI, 1.02-1.75; moderate certainty) and lower use of chest radiography (RR, 0.88; 95% CI, 0.79-0.98; moderate certainty) and blood tests (RR, 0.81; 95% CI, 0.69-0.97; moderate certainty). There was no association with urine testing (RR, 0.95; 95% CI, 0.77-1.17; low certainty), ED length of stay (0 hours; 95% CI, -0.17 to 0.16; moderate certainty), return visits (RR, 0.93; 95%, CI 0.79-1.08; moderate certainty) or hospitalization (RR, 1.01; 95% CI, 0.95-1.08; high certainty). Adults represented 963 participants (16%). There was no association of viral testing with antibiotic use in any prespecified subgroup by age, test method, publication date, number of viral targets, risk of bias, or industry funding. Conclusions and Relevance: The results of this systematic review and meta-analysis suggest that there are limited benefits of routine viral testing in EDs for patients with ARI. Further studies in adults, especially those with high-risk conditions, are warranted.

Diagnostic Stewardship in Community-Acquired Pneumonia With Syndromic Molecular Testing: A Randomized Clinical Trial.

Importance: Lower respiratory tract (LRT) infections, including community-acquired pneumonia (CAP), are a leading cause of hospital admissions and mortality. Molecular tests have the potential to optimize treatment decisions and management of CAP, but limited evidence exists to support their routine use. Objective: To determine whether the judicious use of a syndromic polymerase chain reaction (PCR)-based panel for rapid testing of CAP in the emergency department (ED) leads to faster, more accurate microbiological test result-based treatment. Design, Setting, and Participants: This parallel-arm, single-blinded, single-center, randomized clinical superiority trial was conducted between September 25, 2020, and June 21, 2022, in the ED of Haukeland University Hospital, a large tertiary care hospital in Bergen, Norway. Adult patients who presented to the ED with suspected CAP were recruited. Participants were randomized 1:1 to either the intervention arm or standard-of-care arm. The primary outcomes were analyzed according to the intention-to-treat principle. Intervention: Patients randomized to the intervention arm received rapid syndromic PCR testing (BioFire FilmArray Pneumonia plus Panel; bioMérieux) of LRT samples and standard of care. Patients randomized to the standard-of-care arm received standard microbiological diagnostics alone. Main Outcomes and Measures: The 2 primary outcomes were the provision of pathogen-directed treatment based on a microbiological test result and the time to provision of pathogen-directed treatment (within 48 hours after randomization). Results: There were 374 patients (221 males [59.1%]; median (IQR) age, 72 [60-79] years) included in the trial, with 187 in each treatment arm. Analysis of primary outcomes showed that 66 patients (35.3%) in the intervention arm and 25 (13.4%) in the standard-of-care arm received pathogen-directed treatment, corresponding to a reduction in absolute risk of 21.9 (95% CI, 13.5-30.3) percentage points and an odds ratio for the intervention arm of 3.53 (95% CI, 2.13-6.02; P < .001). The median (IQR) time to provision of pathogen-directed treatment within 48 hours was 34.5 (31.6-37.3) hours in the intervention arm and 43.8 (42.0-45.6) hours in the standard-of-care arm (mean difference, -9.4 hours; 95% CI, -12.7 to -6.0 hours; P < .001). The corresponding hazard ratio for intervention compared with standard of care was 3.08 (95% CI, 1.95-4.89). Findings remained significant after adjustment for season. Conclusions and Relevance: Results of this randomized clinical trial indicated that routine deployment of PCR testing for LRT pathogens led to faster and more targeted microbial treatment for patients with suspected CAP. Rapid molecular testing could complement or replace selected standard, time-consuming, laboratory-based diagnostics. Trial Registration: ClinicalTrials.gov Identifier: NCT04660084.

Emergency Department point-of-care antiviral host response testing is accurate during periods of multiple respiratory virus co-circulation.

OBJECTIVES: FebriDx is a CE-marked, FDA-approved point-of-care test that detects the antiviral host response protein Myxovirus Resistance Protein A (MxA), in addition to C-reactive protein, using finger-prick blood. FebriDx MxA detection had a high negative predictive value for COVID-19 in symptomatic adults presenting to hospital in the first waves of the pandemic and was used subsequently as a 'rule out' triage tool in Emergency departments. The diagnostic accuracy of FebriDx MxA in the current context of co-circulation of influenza, SARS-CoV-2, and Respiratory Syncytial Virus (RSV), and in the era of COVID-19 vaccination, is unknown. METHODS: We retrospectively evaluated the diagnostic performance of FebriDx MxA in adults with acute respiratory symptoms presenting to the Emergency Department (ED) of a large UK teaching hospital using Reverse Transcription Polymerase Chain Reaction (RT-PCR) as the reference standard (Cepheid Xpert Xpress SARS-CoV-2/Flu/RSV). RESULTS: Between March 9th 2022 and March 8th 2023, 5426 patients had both FebriDx and RT-PCR testing with valid results. 999 (18.4%) of patients had influenza detected, 520 (9.6%) SARS-CoV-2, and 190 (3.5%) RSV. Negative Predictive Value (NPV) of MxA detection by FebriDx was 97.5% (96.9-98.0) for influenza, 97.1% (96.4-97.7) for SARS-CoV-2, 98.1% (97.5-98.6) for RSV, and 92.8% (91.8-93.7) for all viruses combined. CONCLUSIONS: In symptomatic adults, FebriDx MxA had a high NPV for influenza and RSV, and retained a high NPV for SARS-CoV-2, in the context of virus co-circulation and widespread COVID-19 vaccination. FebriDx continues to be a useful 'rule out' triage tool in the ED and could potentially be scaled to provide a national triage solution for future viral pandemics.

Routine, molecular point-of-care testing for SARS-CoV-2 and other respiratory viruses within an acute oncology service improves patient care.

OBJECTIVES: COVID-19 has caused significant challenges for infection prevention measures and patient flow in hospital admission pathways. We aimed to assess the impact of replacing laboratory PCR with molecular point-of-care testing (mPOCT) for respiratory viruses including SARS-CoV-2, within an Acute Oncology Service (AOS). METHODS: This pre- and post-implementation study took place in the AOS of a large teaching hospital, in Southampton, UK. We collected data from two periods: November 25th, 2019 to November 24th, 2020, when respiratory virus testing utilised laboratory PCR, and December 1st, 2020 to May 31st, 2021 following the introduction of mPOCT. The primary outcome was the time to results. RESULTS: 2189 patients were tested in the pre-implementation period and 1540 in the post implementation period. Median (IQR) time to results was 5.8 h (4.2-10.6) pre-implementation and 1.9 h (1.5-3.0) post-implementation (difference -3.6 h [95%CI to -3.8 to -3.5]; p < 0.0001). Median time spent in assessment areas was 6.0 h (4.1-7.9) pre-implementation and 5.5 h (3.8-7.4) post-implementation (p < 0.0001). 20 (0.9%) patients admitted via AOS assessment unit developed hospital-acquired respiratory virus infection pre-implementation versus 0 (0%) post-implementation (p = 0.031). CONCLUSIONS: Routine mPOCT for respiratory viruses, including SARS-CoV-2, was associated with a reduced time to results, reduced time in assessment areas, and a reduction in the rates of hospital-acquired respiratory virus infection in an acute oncology assessment unit.

The Impact of Point-of-Care Testing for Influenza on Antimicrobial Stewardship (PIAMS) in UK Primary Care: Protocol for a Mixed Methods Study.

BACKGROUND: Molecular point-of-care testing (POCT) used in primary care can inform whether a patient presenting with an acute respiratory infection has influenza. A confirmed clinical diagnosis, particularly early in the disease, could inform better antimicrobial stewardship. Social distancing and lockdowns during the COVID-19 pandemic have disturbed previous patterns of influenza infections in 2021. However, data from samples taken in the last quarter of 2022 suggest that influenza represents 36% of sentinel network positive virology, compared with 24% for respiratory syncytial virus. Problems with integration into the clinical workflow is a known barrier to incorporating technology into routine care. OBJECTIVE: This study aims to report the impact of POCT for influenza on antimicrobial prescribing in primary care. We will additionally describe severe outcomes of infection (hospitalization and mortality) and how POCT is integrated into primary care workflows. METHODS: The impact of POCT for influenza on antimicrobial stewardship (PIAMS) in UK primary care is an observational study being conducted between December 2022 and May 2023 and involving 10 practices that contribute data to the English sentinel network. Up to 1000 people who present to participating practices with respiratory symptoms will be swabbed and tested with a rapid molecular POCT analyzer in the practice. Antimicrobial prescribing and other study outcomes will be collected by linking information from the POCT analyzer with data from the patient's computerized medical record. We will collect data on how POCT is incorporated into practice using data flow diagrams, unified modeling language use case diagrams, and Business Process Modeling Notation. RESULTS: We will present the crude and adjusted odds of antimicrobial prescribing (all antibiotics and antivirals) given a POCT diagnosis of influenza, stratifying by whether individuals have a respiratory or other relevant diagnosis (eg, bronchiectasis). We will also present the rates of hospital referrals and deaths related to influenza infection in PIAMS study practices compared with a set of matched practices in the sentinel network and the rest of the network. We will describe any difference in implementation models in terms of staff involved and workflow. CONCLUSIONS: This study will generate data on the impact of POCT testing for influenza in primary care as well as help to inform about the feasibility of incorporating POCT into primary care workflows. It will inform the design of future larger studies about the effectiveness and cost-effectiveness of POCT to improve antimicrobial stewardship and any impact on severe outcomes. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/46938.

Clinical impact of syndromic molecular point-of-care testing for gastrointestinal pathogens in adults hospitalised with suspected gastroenteritis (GastroPOC): a pragmatic, open-label, randomised controlled trial.

BACKGROUND: Single-occupancy isolation rooms are a finite resource in UK hospitals but are crucial in preventing transmission of infection. Patients with suspected gastroenteritis are nursed in single-occupancy rooms, but delays in laboratory testing lead to non-infectious patients remaining isolated for prolonged periods unnecessarily. Rapid molecular test panels for gastrointestinal pathogens have a run time of around 1 h but their clinical impact is unknown. We aimed to evaluate the clinical impact of syndromic molecular point-of-care testing (mPOCT) for gastrointestinal pathogens in adult patients presenting to hospital with suspected gastroenteritis on single-occupancy room use and a range of other outcome measures. METHODS: In this pragmatic, open-label, randomised controlled trial, we enrolled adults hospitalised with suspected gastroenteritis in a large UK hospital. Patients were randomly allocated (1:1) to receive syndromic mPOCT of stool or rectal samples, or to routine clinical care (control) with laboratory testing. The primary outcome was the duration of time in single-occupancy rooms assessed on a modified intention-to-treat basis. Secondary outcomes included the time to results, time to de-isolation, antibiotic use, and safety outcomes. The study was registered with ISRCTN, ISRCTN88918395, and is complete. FINDINGS: Between March 20, 2017 and March 17, 2020, from 455 patients assessed for eligibility, we enrolled 278 patients, 138 assigned to mPOCT (one withdrawal) and 140 to the control group. The duration (geometric mean) of single-occupancy room isolation was 1·8 days (95% CI 1·5-2·2) in the mPOCT group compared with 2·6 days (2·2-3·0) in the control group (exponentiated coefficient 0·70 [95% CI 0·56 to 0·87]; p=0·0017). The median (IQR) time to results was 1·7 h (1·5-2·0) for mPOCT and 44·7 h (21·2-66·1) for the control group (p<0·0001). Time to de-isolation was 0·6 days (0·3-1·8) in the mPOCT group compared with 2·2 days (1·2-3·2) in the control group, (p<0·0001). Antibiotics were given in 89 (65%) of 137 in the mPOCT group and 66 (47%) of 140 in the control group (p=0·0028). There were no differences between groups in length of hospital stay, or in safety outcomes including mortality, intensive care unit admission, or readmission to hospital. INTERPRETATION: mPOCT for gastrointestinal pathogens in patients with suspected gastroenteritis returned results more rapidly than conventional testing and was associated with a reduction in single-occupancy room use. However, these benefits need to be balanced against a potential increase in antibiotic use. FUNDING: University Hospital Southampton NHS Foundation Trust.

Rapid multiplex PCR for respiratory viruses reduces time to result and improves clinical care: Results of a systematic review and meta-analysis.

OBJECTIVES: The clinical impact of rapid sample-to-answer "syndromic" multiplex polymerase chain reaction (PCR) testing for respiratory viruses is not clearly established. We performed a systematic literature review and meta-analysis to evaluate this impact for patients with possible acute respiratory tract infection in the hospital setting. METHODS: We searched EMBASE, MEDLINE, and Cochrane databases from 2012 to present and conference proceedings from 2021 for studies comparing clinical impact outcomes between multiplex PCR testing and standard testing. RESULTS: Twenty-seven studies with 17,321 patient encounters were included in this review. Rapid multiplex PCR testing was associated with a reduction of - 24.22 h (95% CI -28.70 to -19.74 h) in the time to results. Hospital length of stay was decreased by -0.82 days (95% CI -1.52 to -0.11 days). Among influenza positive patients, antivirals were more likely to be given (RR 1.25, 95% CI 1.06-1.48) and appropriate infection control facility use was more common with rapid multiplex PCR testing (RR 1.55, 95% CI 1.16-2.07). CONCLUSIONS: Our systematic review and meta-analysis demonstrates a reduction in time to results and length of stay for patients overall along with improvements in appropriate antiviral and infection control management among influenza-positive patients. This evidence supports the routine use of rapid sample-to-answer multiplex PCR testing for respiratory viruses in the hospital setting.

Blood gene expression predicts intensive care unit admission in hospitalised patients with COVID-19.

Background: The COVID-19 pandemic has created pressure on healthcare systems worldwide. Tools that can stratify individuals according to prognosis could allow for more efficient allocation of healthcare resources and thus improved patient outcomes. It is currently unclear if blood gene expression signatures derived from patients at the point of admission to hospital could provide useful prognostic information. Methods: Gene expression of whole blood obtained at the point of admission from a cohort of 78 patients hospitalised with COVID-19 during the first wave was measured by high resolution RNA sequencing. Gene signatures predictive of admission to Intensive Care Unit were identified and tested using machine learning and topological data analysis, TopMD. Results: The best gene expression signature predictive of ICU admission was defined using topological data analysis with an accuracy: 0.72 and ROC AUC: 0.76. The gene signature was primarily based on differentially activated pathways controlling epidermal growth factor receptor (EGFR) presentation, Peroxisome proliferator-activated receptor alpha (PPAR-α) signalling and Transforming growth factor beta (TGF-ß) signalling. Conclusions: Gene expression signatures from blood taken at the point of admission to hospital predicted ICU admission of treatment naïve patients with COVID-19.

Molecular point-of-care testing for lower respiratory tract pathogens improves safe antibiotic de-escalation in patients with pneumonia in the ICU: Results of a randomised controlled trial.

BACKGROUND: Effective treatment of pneumonia requires timely administration of appropriate antimicrobials but standard diagnostic tests take around 48 h to generate results. Highly accurate, rapid molecular tests have been developed for identifying organisms in lower respiratory tract samples, however their impact on antibiotic use is unknown. The aim of this study was to assess the impact of syndromic molecular point-of-care testing compared to conventional diagnostic testing, on antibiotic use. METHODS: In this pragmatic, randomised controlled trial, we enrolled critically ill adults with pneumonia. Patients were assigned (1:1) to molecular testing of samples at the point-of-care or routine clinical care. The primary outcome was the proportion of patients who received results-directed antimicrobial therapy. RESULTS: 200 patients were randomly assigned to point-of-care testing (n = 100) or the control group (n = 100). 85 patients had community acquired pneumonia (42 in the mPOCT group and 43 in the control group), 69 hospital acquired pneumonia (30 in mPOCT and 39 in control) and 46 ventilator associated pneumonia (28 in mPOCT and 18 in control). The median [IQR] time to results was 1.7 [1.6-1.9] hours for point-of-care testing and 66.7 [56.7-88.5] hours for standard diagnostics (difference of -65.0 h, 95%CI -68.0 to -62.0; p < 0.0001). 71 (71%) patients in the point-of-care testing arm had pathogens detected compared to 51 (51%) in the control arm (difference of 20%, 95%CI 7 to 33; p = 0.004). 80 (80%) of patients in the point-of-care group received results-directed therapy, compared with 29 (29%) of 99 in the control group (difference of 51%, 95%CI 39-63; p < 0.0001). Time to results-directed therapy was 2.3 [1.8-7.2] hours in the mPOCT group and 46.1 [23.0-51.5] hours in the control group (difference of -43.8 h, 95% CI -48.9 to -38.6; p < 0.0001). 42 (42%) patients in mPOCT group had antibiotics de-escalated compared with 8 (8%) of 98 in the control group (difference of 34%, 95%CI 23-45; p < 0.0001). Time to de-escalation was 4.8 [2.4-13.0] hours in the mPOCT group compared with 46.5 [26.3-48.6] hours in the control group (difference of -41.4 h, 95%CI -53 to -29.7; p < 0.0001). There was no major difference in antibiotic duration or in clinical or safety outcomes between the two groups. CONCLUSIONS: Use of molecular point-of-care testing in patients with pneumonia returned results more rapidly and identified more pathogens than conventional testing. This was associated with improvements in appropriate antimicrobial use and appeared safe.

Impact of rapid molecular testing on diagnosis, treatment and management of community-acquired pneumonia in Norway: a pragmatic randomised controlled trial (CAPNOR).

BACKGROUND: Community-acquired pneumonia (CAP) causes a large burden of disease. Due to difficulties in obtaining representative respiratory samples and insensitive standard microbiological methods, the microbiological aetiology of CAP is difficult to ascertain. With a few exceptions, standard-of-care diagnostics are too slow to influence initial decisions on antimicrobial therapy. The management of CAP is therefore largely based on empirical treatment guidelines. Empiric antimicrobial therapy is often initiated in the primary care setting, affecting diagnostic tests based on conventional bacterial culture in hospitalized patients. Implementing rapid molecular testing may improve both the proportion of positive tests and the time it takes to obtain test results. Both measures are important for initiation of pathogen-targeted antibiotics, involving rapid de-escalation or escalation of treatment, which may improve antimicrobial stewardship and potentially patient outcome. METHODS: Patients presenting to the emergency department of Haukeland University Hospital (HUH) in Bergen, Norway, will be screened for inclusion into a pragmatic randomised controlled trial (RCT). Eligible patients with a suspicion of CAP will be included and randomised to receive either standard-of-care methods (standard microbiological testing) or standard-of-care methods in addition to testing by the rapid and comprehensive real-time multiplex PCR panel, the BioFire® FilmArray® Pneumonia Panel plus (FAP plus) (bioMérieux S.A., Marcy-l'Etoile, France). The results of the FAP plus will be communicated directly to the treating staff within ~2 h of sampling. DISCUSSION: We will examine if rapid use of FAP plus panel in hospitalized patients with suspected CAP can improve both the time to and the proportion of patients receiving pathogen-directed treatment, thereby shortening the exposure to unnecessary antibiotics and the length of hospital admission, compared to the standard-of-care arm. The pragmatic design together with broad inclusion criteria and a straightforward intervention could make our results generalizable to other similar centres. TRIAL REGISTRATION: ClinicalTrials.gov NCT04660084 . Registered on December 9, 2020.

Respiratory virus transmission using a novel viral challenge model: An observational cohort study.

OBJECTIVES: Knowledge of Acute Respiratory virus Infection (ARI) is limited in relation to their substantial global burden. We completed a feasibility study of a novel method to study the natural transmission of respiratory viruses from young children to adults in hospital. METHODS: Between September 2012 and May 2015, we recruited healthy adults (contacts) and paediatric inpatients with ARIs (index) presenting to the University Hospitals Leicester NHS Trust, Leicester, UK. We took nose and throat swabs from all participants prior to controlled, 30 minute interactions between the children with ARIs and adult contacts. Contacts recorded symptoms and provided four nose and throat swabs over ten days post-interaction, which were tested for a panel of respiratory viruses to assess transmission. RESULTS: 111 interactions occurred between children with ARIs and adult contacts. Respiratory viruses were detected in 103 of 111 children (93%), most commonly rhinoviruses (RVs) (67 of 103, 65%). Transmission to an adult contact occurred in 15 (14·6%) of 103 interactions and was inversely associated with the contact being male (adjusted OR 0·12; 95% CI 0·02-0·72). CONCLUSION: Using a novel methodology, we found that natural transmission of ARIs occurred in 15% of an infected child's contacts following a 30 minute interaction, primarily by RVs and when the contact was female. Our model has key advantages in comparison with human challenge studies making it well-suited for further studies of respiratory virus transmission, disease pathogenesis, and clinical and public health interventions to interrupt transmission.

Evaluating the Immune Response in Treatment-Naive Hospitalised Patients With Influenza and COVID-19.

The worldwide COVID-19 pandemic has claimed millions of lives and has had a profound effect on global life. Understanding the body's immune response to SARS-CoV-2 infection is crucial in improving patient management and prognosis. In this study we compared influenza and SARS-CoV-2 infected patient cohorts to identify distinct blood transcript abundances and cellular composition to better understand the natural immune response associated with COVID-19, compared to another viral infection being influenza, and identify a prognostic signature of COVID-19 patient outcome. Clinical characteristics and peripheral blood were acquired upon hospital admission from two well characterised cohorts, a cohort of 88 patients infected with influenza and a cohort of 80 patients infected with SARS-CoV-2 during the first wave of the pandemic and prior to availability of COVID-19 treatments and vaccines. Gene transcript abundances, enriched pathways and cellular composition were compared between cohorts using RNA-seq. A genetic signature between COVID-19 survivors and non-survivors was assessed as a prognostic predictor of COVID-19 outcome. Contrasting immune responses were detected with an innate response elevated in influenza and an adaptive response elevated in COVID-19. Additionally ribosomal, mitochondrial oxidative stress and interferon signalling pathways differentiated the cohorts. An adaptive immune response was associated with COVID-19 survival, while an inflammatory response predicted death. A prognostic transcript signature, associated with circulating immunoglobulins, nucleosome assembly, cytokine production and T cell activation, was able to stratify COVID-19 patients likely to survive or die. This study provides a unique insight into the immune responses of treatment naïve patients with influenza or COVID-19. The comparison of immune response between COVID-19 survivors and non-survivors enables prognostication of COVID-19 patients and may suggest potential therapeutic strategies to improve survival.

Combined RT-PCR and Host Response Point-of-Care Testing in Patients Hospitalised with Suspected COVID-19: A Prospective Diagnostic Accuracy Study.

INTRODUCTION: RT-PCR has suboptimal sensitivity for the diagnosis of COVID-19. A composite reference standard comprising RT-PCR plus radiological and clinical features has been recommended for diagnostic accuracy studies. The FebriDx finger prick point-of-care test detects an antiviral host response protein (MxA) in 10 min. We evaluated the diagnostic accuracy of FebriDx and RT-PCR compared to a composite reference standard. METHODS: Adults presenting to hospital with suspected COVID-19 were tested by FebriDx and RT-PCR. A composite reference standard was used to classify patients as having COVID-19 based on RT-PCR positivity, or RT-PCR negativity with COVID-19 radiological findings or other clinical criteria. Measures of accuracy were calculated for MxA alone, RT-PCR alone, and both combined. This study is registered with the ISRCTN (ISRCTN14966673) and has completed. RESULTS: A total of 478 patients were tested, with valid results in 475. Of these 475 patients, 222 (46.7%) were classified as having COVID-19; 192 (40.4%) were RT-PCR positive, and 30 (6.3%) were RT-PCR negative and diagnosed on radiological/clinical criteria. Sensitivity of FebriDx MxA vs the composite reference standard was 186/222 (83.8%, 95% CI 78.3-88.4) and was similar to the sensitivity of RT-PCR (192/222 (86.5%, 95% CI 81.3-90.7), (difference of 2.7%, 95% CI - 3.9 to 9.3, p = 0.42). The sensitivity of combined FebriDx and RT-PCR was 208/222 (93.7%) which was superior to both RT-PCR alone (difference of 9.9, 95% CI 4.1-15.9; p = 0.001) and FebriDx MxA alone (difference of 7.2, 95% CI 1.6-12.9; p = 0.011). CONCLUSION: Sensitivity of combined FebriDx and RT-PCR testing was superior to each alone for the detection of COVID-19 in hospital and may improve infection control and treatment decisions.

Routine molecular point-of-care testing for SARS-CoV-2 reduces hospital-acquired COVID-19.

OBJECTIVES: Risk of hospital-acquired COVID-19 (HA-COVID-19) infection is increased by cohorting infected and non-infected patients together in assessment areas, whist awaiting laboratory PCR results. Molecular point-of-care tests (mPOCT) reduce time to results and improve patient flow but the impact on HA-COVID-19 is unknown. METHODS: In this pre and post implementation study patients were evaluated across two time periods: March 1st to August 13th 2020, prior to the introduction of mPOCT in medical admissions areas, and 14th August 2020 to 1st April 2021, after mPOCT introduction. The primary outcome was proportion of HA-COVID-19 infection among all COVID-19 positive patients. Secondary outcome measures included time to SARS-CoV-2 results, length of time spent in the medical assessment area and comparison of local, regional and national proportions of HA-COVID-19. RESULTS: 1988 patients were admitted through the acute medicine admission cohorting area and tested for SARS-CoV-2 prior to introducing mPOCT and 4640 afterwards. Median (IQR) time to SARS-CoV-2 result was 6.5 (2.1-17.9) hours prior to introducing mPOCT and 1.0 (0.8-1.3) hours afterwards (p < 0.0001). Median (IQR) duration in the assessment cohort area was 12.0 (4.8-20.6) hours prior to introduction of POCT and 3.2 (2.0-5.6) hours afterwards (p < 0.0001). The proportion of hospital-acquired COVID-19 cases was 108 (16.5%) of 654 prior to introducing mPOCT compared with 168 (9.4%) of 1782 afterwards, (HR 0.55, 95%CI 0.43-0.70; p < 0.0001). In the period following the introduction of mPOCT up to 1st April 2021 the median proportion of HA-COVID-19 was 13.6% (95%CI 8.2-18.9%) locally, compared with 43.8% (95%CI 37.8-49.9%) for all acute NHS trusts regionally and 30.9% (95%CI 28.4-33.5%) for all NHS trusts nationally. CONCLUSIONS: Routine mPOCT for SARS-CoV-2 was associated with reduced time to results, time spent in admission cohort areas, and hospital-acquired COVID-19, compared to laboratory PCR.

FebriDx host response point-of-care testing improves patient triage for coronavirus disease 2019 (COVID-19) in the emergency department.

OBJECTIVES: Patients presenting to hospital with suspected coronavirus disease 2019 (COVID-19), based on clinical symptoms, are routinely placed in a cohort together until polymerase chain reaction (PCR) test results are available. This procedure leads to delays in transfers to definitive areas and high nosocomial transmission rates. FebriDx is a finger-prick point-of-care test (PoCT) that detects an antiviral host response and has a high negative predictive value for COVID-19. We sought to determine the clinical impact of using FebriDx for COVID-19 triage in the emergency department (ED). DESIGN: We undertook a retrospective observational study evaluating the real-world clinical impact of FebriDx as part of an ED COVID-19 triage algorithm. SETTING: Emergency department of a university teaching hospital. PATIENTS: Patients presenting with symptoms suggestive of COVID-19, placed in a cohort in a 'high-risk' area, were tested using FebriDx. Patients without a detectable antiviral host response were then moved to a lower-risk area. RESULTS: Between September 22, 2020, and January 7, 2021, 1,321 patients were tested using FebriDx, and 1,104 (84%) did not have a detectable antiviral host response. Among 1,104 patients, 865 (78%) were moved to a lower-risk area within the ED. The median times spent in a high-risk area were 52 minutes (interquartile range [IQR], 34-92) for FebriDx-negative patients and 203 minutes (IQR, 142-255) for FebriDx-positive patients (difference of -134 minutes; 95% CI, -144 to -122; P < .0001). The negative predictive value of FebriDx for the identification of COVID-19 was 96% (661 of 690; 95% CI, 94%-97%). CONCLUSIONS: FebriDx improved the triage of patients with suspected COVID-19 and reduced the time that severe acute respiratory coronavirus virus 2 (SARS-CoV-2) PCR-negative patients spent in a high-risk area alongside SARS-CoV-2-positive patients.

A SARS-CoV-2 nucleocapsid ELISA represents a low-cost alternative to lateral flow testing for community screening in LMI countries.

Background Controlling the spread of SARS-CoV-2 is problematic because of transmission driven by asymptomatic and pre-symptomatic individuals. Community screening can help identify these individuals but is often too expensive for countries with limited health care resources. Low-cost ELISA assays may address this problem, but their use has not yet been widely reported. Methods We developed a SARS-CoV-2 nucleocapsid ELISA and assessed its diagnostic performance on nose and throat swab samples from UK hospitalised patients and sputum samples from patients in Ghana. Results The ELISA had a limit of detection of 8.4 pg/ml antigen and 16 pfu/ml virus. When tested on UK samples (128 positive and 10 negative patients), sensitivity was 58.6% (49.6-67.2) rising to 78.3% (66.7-87.3) if real-time PCR Ct values > 30 were excluded, while specificity was 100% (69.2-100). In a second trial using the Ghanaian samples (121 positive, 96 negative), sensitivity was 52% (42.8-61.2) rising to 72.6% (61.8-81.2) when a > 30 Ct cut-off was applied, while specificity was 100% (96.2-100). Conclusions: Our data show that nucleocapsid ELISAs can test a variety of patient sample types while achieving levels of sensitivity and specificity required for effective community screening. Further investigations into the opportunities that this provides are warranted.