COVID-19 diagnosis
The RT-PCR was performed by an
experienced microbiologist (D.M.) in the LHUB-ULB laboratory of Brussels
(Laboratoire Hospitalier Universitaire de Bruxelles, Belgium). Viral RNA
extraction was performed by m2000 mSample Preparation SystemDNA Kit
(Abbott) using 1000µl manually lysed sample (700µl sample + 800µl lysis
buffer from kit) eluted in 90µl elution buffer. A qRT-PCR internal
control was added at each extraction. qRT-PCR was performed using 10µl
of extracted sample in the RealStar®SARS-CoV-2 RT-PCR
Kit from Altona-diagnostics with a cut-off set at 40 cycle threshold
(Ct).
Patients with a negative RT-PCR benefited from a serological test
(Zentech, University of Liege Lab, Liege, Belgium) to determine whether
or not they have been exposed to SARS-Cov-2.