The investigators will collect residuary lung tissue after medically indicated pulmonary resections at the Thoracic Surgery Department of University Hospitals Leuven. More specifically the investigators will collect lung tissue from patients that had earlier PCR proven COVID-19 and/or serum anti-SARS-CoV-2 antibodies.~Furthermore, for negative control of the methodology the investigators will also collect lung tissue from patients that have no signs for earlier SARS-CoV-2 infection.
The aim of this study is to confirm or rule out the residual presence and viability of SARS- CoV-2 in the respiratory tract and lung parenchyma of patients previously infected with SARS-CoV-2.~Presence and viability of SARS-CoV-2 in lung tissue will be assessed with reverse transcriptase-polymerase chain reaction (PCR) and viral culture. The histological location of residual SARS-CoV-2 will be determined with fluorescence immunohistochemistry and single molecule fluorescence in situ hybridization, targeting viral proteins and RNA respectively.