id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-277307-wabruzfs	Gu, Wei	Associations of Early COVID-19 Cases in San Francisco with Domestic and International Travel	2020-05-21		.txt	text/plain	1096	79	66	In San Francisco, we validated a qRT-PCR test to detect SARS-CoV-2 infection from nasopharyngeal swab samples based on the EUA (Emergency Use Authorization)approved US CDC assay 3 . Those who did not have a recent travel history, a close contact who was COVID-19 positive, or were not a frontline healthcare worker were categorized as community transmission with an unknown source of infection and comprised 39% of cases. Viruses in the G clade comprise most of the genomes sequenced from patients in Europe 8, 9 , but notably have also been identified in the vast majority of cases associated with the New York SARS-CoV-2 outbreak in March to April of 2020, which occurred after the timeline of this study 11, 12 Viruses from two additional travel-associated cases from Europe (UC43) and New York (UC41) were mapped to other clades circulating in Europe (Figure 2) . Sequencing identifies multiple, early introductions of SARS-CoV2 to New York City Region	./cache/cord-277307-wabruzfs.txt	./txt/cord-277307-wabruzfs.txt