id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-352228-dzkf7c7l	Fontanet, Arnaud	Cluster of COVID-19 in northern France: A retrospective closed cohort study	2020-04-23		.txt	text/plain	4248	225	54	Methods: Between 30 March and 4 April 2020, we conducted a retrospective closed cohort study among pupils, their parents and siblings, as well as teachers and non-teaching staff of a high-school located in Oise. Participants completed a questionnaire that covered history of fever and/or respiratory symptoms since 13 January 2020 and had blood tested for the presence of anti-SARS-CoV-2 antibodies. Interpretation: The relatively low IAR observed in an area where SARS-CoV-2 actively circulated weeks before confinement measures indicates that establishing herd immunity will take time, and that lifting these measures in France will be long and complex. Using a combination of serologic assays with high sensitivity and specificity for anti-SARS-CoV-2 antibodies, we conducted a retrospective closed cohort study. This is, to our knowledge, the first study estimating by antibody detection the IAR of SARS-CoV-2 infection in a community affected by COVID-19, and the fist description of a COVID-19 outbreak in a school.	./cache/cord-352228-dzkf7c7l.txt	./txt/cord-352228-dzkf7c7l.txt