Detection of SARS-CoV-2 pneumonia

$\bf Background:$ Developing therapeutic strategies for a SARS-CoV-2 infection is challenging, but first the correct diagnosis has to be made. Unspecific upper and lower respiratory tract symptoms can be misleading; hence, a nasopharyngeal swab test with a real-time reverse-transcription-polymerase chain reaction is of great importance. However, early viral clearing jeopardizes a sound diagnosis of COVID-19. $\textbf {Case presentation:}$ We report on two Caucasian patients who had negative pharyngeal swab tests at the onset of SARS-CoV-2 pneumonia. In one patient, the virus was not even detectable in bronchoalveolar lavage despite typical radiomorphologic changes. $\bf Conclusions:$ Negative PCR findings in both the pharynx and bronchoalveolar lavage do not exclude COVID-19 pneumonia. Computed tomography is a crucial diagnostic prerequisite in this context