Case 1 was a 66 year old male experiencing symptoms of shortness of breath, fever and muscle pain since 8 days. Lab findings showed thrombopenia (87,000/µL, ref. 149,000–31,9000/µL), lymphopenia (930/µL, ref. 1,133–3,105/µL), normal neutrophil count (2,980/µL, ref. 1,573–6,100/µL) low eosinophil count (0/µL, ref. 28–273/µL), normal basophil count (10/µL, ref. 6–50/µL), elevated D-dimers (1,480 ng/mL, ref. <500 ng/mL) and elevated C-reactive protein (29 mg/L, ref <5 mg/L). Chest CT on the day of admission showed bilateral ground glass opacities with a crazy paving pattern suspicious for COVID-19 (CT severity score of 10 or CO-RADS classification of 4: COVID-19 likely). Repetitive nasopharyngeal swabs on day 8, 9, 12 and 13 as well as anal swabs on day 9 and 13 after symptom onset were all SARS-CoV-2 RT-PCR negative using the protocol described by Corman and colleagues [6]. Serology on day 13 after symptom onset indicated negative IgM but positive IgG (Prima Professional®, Point-Of-Care antibody Tests). On day 13, the patient was admitted to the intensive care unit (ICU) because of type 1 respiratory insufficiency (pO2 60 mmHg, ref. 83–108 mm Hg; pCO2 31 mmHg, ref. 35–45 mm Hg; pH 7.46, ref. 7.35–7.45). He did not require mechanical ventilation. Based on these findings, he was diagnosed with COVID-19.