id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-316493-wszoi6p2	Zhou, Weimin	First infection by all four non-severe acute respiratory syndrome human coronaviruses takes place during childhood	2013-09-16		.txt	text/plain	4322	237	55	BACKGROUND: Non-severe acute respiratory syndrome (non-SARS)-related human coronaviruses (HCoVs), including HCoV-229E, -HKU1, -NL63, and -OC43, have been detected in respiratory tract samples from children and adults. An S-protein-based indirect immunofluorescence assay (IFA) was then developed to detect anti-S IgG and IgM for the four individual HCoVs and applied to serum samples from a general asymptomatic population (218 children and 576 adults) in Beijing. To expand the epidemiological knowledge of four non-SARS-related endemic HCoVs in China, we expressed S proteins in a eukaryotic system and established an IFA for the detection of IgG or IgM antibodies against these four viruses. Our results showed that the S-based IFA enabled specific detection of IgG or IgM to four individual HCoVs. Using IFA, we investigated the natural seroprevalence of four non-SARS-related HCoVs in blood samples from a general population that comprised a variety of age groups.	./cache/cord-316493-wszoi6p2.txt	./txt/cord-316493-wszoi6p2.txt