Summary

Advice

The technology described in this briefing is FebriDx. It is a rapid dual marker immunoassay test. The test detects raised levels of C-reactive protein (CRP) and myxovirus resistance protein A (MxA) in peripheral whole blood. The test is done at the point of care and gives results in 10 minutes.
The innovative aspects are that the FebriDx test measures MxA, a marker for viral infection, as well as CRP. This helps clinicians to differentiate between bacterial and viral respiratory tract infections.
The intended place in therapy would be in primary or secondary care, to help guide the appropriate use of antibiotics for people with acute febrile respiratory tract infections. It could also help with early detection of viral infections, such as COVID‑19.
The main points from the evidence summarised in this briefing are from 43 diagnostic accuracy studies (2 in COVID‑19), 4 feasibility studies and 1 clinical evaluation (including 1,133 people in total). The evidence suggests that FebriDx is effective, meaning it has high sensitivity (over 80%) and specificity (over 90%) when identifying bacterial and viral infections in adults. It could also help with diagnosis in children. The emerging evidence of the test for people with viral infections, such as COVID‑19, suggests it could have benefits as an early triage tool.
Key uncertainties around the evidence are that there is currently only 1 published study exclusively in children and 1 published study for people with suspected COVID‑19. There is limited follow-up evidence looking at the effect of the test on antibiotic use. Most of the evidence was on a previous format of the technology; the new integrated format is identical in performance to the earlier device.
The cost of FebriDx is £12.75 (excluding VAT), which would be in addition to standard care. There is published evidence suggesting that FebriDx could save costs by reducing antibiotic use and avoiding complications associated with this.