id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-283823-8n1cy0hj	Parikh, Bijal A.	The Brief Case: “Not Positive” or “Not Sure”—COVID-19-Negative Results in a Symptomatic Patient	2020-07-23		.txt	text/plain	1618	84	49	The diagnosis of SARS-CoV-2 has relied almost exclusively on molecular testing of upper and lower respiratory specimens. As of 7 April 2020 (when the BAL fluid sample for this patient was sent to a reference laboratory for testing), 28 of the 29 commercially available assays approved by the FDA for emergency use were for testing on nasopharyngeal swabs (Table 1 ). Case reports of SARS-CoV-2 detection in sputum, tracheal aspirate, and BAL fluid specimens suggest that these specimens may be positive when NP swabs are negative, though large-scale studies have yet to be published (5) . It has become clear that negative NP swabs alone do not rule out SARS-CoV-2 infection, and as of now, there is no single "ideal" specimen for the diagnosis of COVID-19 (5) . Updated IDSA (Infectious Diseases Society of America) guidelines for COVID-19 diagnosis describe an algorithmic approach based on patient symptomatology, suspicion for infection, hospitalization status, and availability of lower respiratory specimens (6) . SARS-CoV-2 viral load in upper respiratory specimens of infected patients	./cache/cord-283823-8n1cy0hj.txt	./txt/cord-283823-8n1cy0hj.txt