Persistent viral infectivity after 27 days from COVID-19 symptoms onset

Abstract

The persistence of SARS-CoV-2 in pharyngeal swabs belonging to patients affected by COVID-19 is not a rare occurrence. Indeed, the viral load determined through real-time reverse-transcriptase PCR (rRT-PCR) test peaks at the onset of symptoms and decreases to undetectable level within 1–3 weeks.1

Nevertheless, few studies investigated the potential infectivity of the clinical specimens, and to date viral culture isolation failed after some weeks from the first symptoms,1 being the 18th day the last timing in which virus replication in vitro was achieved in immunocompetent host.2

Here we report the case of SARS-CoV-2 infection positivity at the molecular test after 42 days, describing successful viral replication in vitro obtained after 27 days from the first positive swab.

A 58-year-old man resulted positive to SARS-CoV-2 during routine screening for health workers; he was initially asymptomatic. He underwent isolation and was treated with lactoferrin, vitamin C and D. The subsequent day after testing positive, swab specimens from his wife and daughter yielded positive for SARS-CoV-2 infection; however, they returned negative after 15 and 10 days, respectively. After 4 days he developed fever (max 38.7°C) and cough and was treated with paracetamol and levocloperastine. At the seventh day after the swab positivity he aggravated and presented dyspnoea exertional, although with 94%–97% saturation and no pulmonary abnormalities evidenced by direct lung auscultation; treatment with azithromycin (500 mg/day) for 6 days was started. After 3 days of treatment, he did not show fever. After 23 days he continued to have a cough that was successfully treated with prednisone (50 mg/day for 4 days, 25 mg/day for 2 days, 12.5 mg/day for 2 days). At the haematologic analysis the unique alteration regarded an increment of D-dimer (D-dimer=996 ng/mL), a characteristic associated with a hypercoagulative status often found in severe cases of COVID-19.3 Treatment with fodaparinux (2.5 mg/day for 10 days) was initiated.