Abstract
Background Differentiating viral from bacterial acute
respiratory infections (ARIs) remains challenging, due to the
non-specific clinical manifestations. The COVID-19 pandemic is putting
extraordinary strain on healthcare resources. To date, molecular testing
is available but has a long turnaround time and therefore cannot provide
results at the point-of-care (POC) thereby exposing
COVID-19/Non-COVID-19 patients to each other while awaiting diagnosis.
Methods This observational study prospectively evaluated
the utility of a triage strategy including FebriDx, a POC fingerstick
blood test that differentiates viral from bacterial ARIs through
simultaneous detection of Myxovirus-resistance protein A (MxA) and
C-reactive protein (CRP), in rapidly determining viral cases requiring
immediate isolation and confirmatory molecular testing, from
non-infectious patients or bacterial infections requiring antibiotics.
Results 75 consecutive patients were screened, 48
eligible cases were tested with FebriDx, 36 were confirmed viral
infection and 35/36 had COVID-19. 31/35 COVID-19 cases tested positive
for SARS-CoV-2 via rRT-PCR and (4/35) had a clinical diagnosis of
probable COVID-19 based on symptoms, epidemiological history, and chest
imaging (PPV 100% (35/35)). 13 cases were FebriDx viral negative and
rRT-PCR was also negative. In one case, it was not possible to determine
the exact cause of infection, although a viral infection could not be
excluded. Including this patient, FebriDx NPV was 92.3% (12/13),
exceeding the NPV of rRT-PCR a 68.3% (13/19), and diagnostic
sensitivity was conservatively calculated at 97% (35/36) compared to
82.9% (29/35) for initial rRT-PCR. The diagnostic specificity of both
FebriDx and rRT-PCR was 100%.
Conclusions : FebriDx could be deployed as part of a
reliable triage strategy for identifying possible COVID-19 patients with
symptomatic ARI in the COVID-19 pandemic.
Key words: Pandemic; COVID-19; SARS-CoV-2; pneumonia; viral;
point of care; infection