Comparison of the performance of Host Immune ResPonse tests for distinguishing bacterial and viral acute respiratory infection
Comparing diagnostic accuracy of different host response tests in acute respiratory illness in adults
Current interventions as of 17/09/2025: This study will consist of a diagnostic accuracy study comparing different host response tests (Febri-Dx, MeMed BV, Inflammatix TriVerity, Bi-VirTest) in response to acute respiratory infection, in the form of a prospectively recruited study. Adult patients presenting to ED or Acute Medical Unit with symptoms susceptive of acute respiratory infection will be recruited and samples will be collected. Recruits will have a point-of-care Febri-Dx and Bi-VirTest taken at enrolment and further blood samples will be stored for retrospective Inflammatix TriVerity and MeMed BV testing. Three nasopharyngeal swabs will be collected - one to test for viral respiratory infections needed to help guide clinical adjudication and the other two frozen if further diagnostic work is needed. Additionally, serum, EDTA and Paxgene samples will be stored if further diagnostic work is needed. The results of the FebriDx/Bi-VirTest/MeMed BV/TriVerity test will not be made available to the patient or treating clinical staff in the emergency department or acute medical unit. The routine nasopharyngeal swab for viral pathogen result will be available as part of routine clinical care. Acute patient participation in the study will end after sample collection. Due to the low risk and brief nature of the patient involvement in the study, and that no routine deviation from routine clinical care is planned, no active observation and follow-up of patients post participation is needed. Routine outcome date will be collected. Blinded clinical adjudication of infectious status (non, viral, bacterial, co-infection) will be the reference standard which diagnostic accuracy is calculated. Positive Percentage Agreement (PPA), Negative Percentage Agreement (NPA), Positive Predictive Value (PPV), Negative Predictive Value (NPV), Overall accuracy, AUROC, all with 95% confidence intervals. A secondary exploratory objective includes evaluating the equivalence of EDTA blo
1. Is a patient in the ED or AMU, Southampton General Hospital, UHS 2. Aged ≥18 years old 3. Able to be recruited and sampled within 24 hours of arrival in the ED or AMU 4. Has the capacity to consent to the study 5. Has at least one of the following acute respiratory symptoms: 5.1. Cough 5.2. Shortness of breath 5.3. Coryza 5.4. Sore Throat 5.5. Wheeze 5.6. Fever (where not definitively explained by another cause) 5.7. Reported exacerbation of a chronic respiratory condition (e.g., asthma, COPD)
1. Not fulfilling all inclusion criteria 2. Declines nasal/pharyngeal swabbing, finger prick testing or venesection 3. Underlying severe bronchiectasis, cystic fibrosis, severe immune suppression