Covid-19 Rapid Diagnostic Tests on Blood Drop

The Covid-19 pandemic requires a reliable diagnosis of affected patients in order to manage
them in an appropriate manner, in the appropriate departments. Furthermore, the diagnostic
reference at the time of this study is based on reverse transcription by reaction in
polymerase chain reaction (RT-PCR) on a nasopharyngeal swab taken. This method has may yield
false negatives (up to 30% depending on the series) and its lead time is several hours.

Alternatives are therefore being developed, in particular rapid blood tests. The rapid
diagnostic test distributed by Biosynex has been evaluated by the National Reference Center
for Respiratory Infections Viruses as very specific for the detection of IgG + IgM (93%).

As part of the evaluation of this test, it was used in patients with severe Covid-19 disease,
requiring hospitalization in critical care in order to be able to establish their reliability
in a clinical context where many confounding factors may occur, such as lymphopenia or
systemic inflammation. However, the early diagnosis of this patient population remains
critical in order to be able to refer them to the appropriate services.