Undetectable SARS-CoV-2 in a nasopharyngeal swab but persistent viral RNA from deep lung swabs: findings from an autopsy

Abstract

During the global pandemic of COVID-19 accurate diagnosis of the infection by demonstrating SARS-CoV-2 viral RNA by PCR in specimens is crucial for therapeutic and preventative interventions. There have been instances where nasal and throat swabs have been negative despite the patient having typical clinical and radiological findings compatible with the disease. We report a case of a man in his late 50s, brought to the hospital following a cardiac arrest and prolonged unsuccessful resuscitation. The history was typical for COVID-19 with fever for 10 days and worsening shortness of breath. His throat and nasal swabs (after death) were negative for SARS-CoV-2. A limited diagnostic autopsy was performed after 27 days, and lung swabs confirmed presence of SARS-CoV-2. This case highlights the importance of lung swabs when initial upper respiratory tract swabs are negative and proves that the virus can be detected from dead human tissue almost a month later.