id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-290352-0pc5eji4	de Jong, Menno D.	Avian influenza A (H5N1)	2005-10-06		.txt	text/plain	9156	412	41	Since their reemergence in 2003, highly pathogenic avian influenza A (H5N1) viruses have reached endemic levels among poultry in several southeast Asian countries and have caused a still increasing number of more than 100 reported human infections with high mortality. However, occurrences of direct bird-to-human transmission of avian influenza viruses have increasingly been reported in recent years, culminating in the ongoing outbreak of influenza A (H5N1) among poultry in several Asian countries with associated human infections. The "Asian influenza" pandemic of 1957 was caused by an H2N2 virus that had acquired three genes (H2, N2, and PB1) from avian viruses infecting wild ducks, in a backbone of the circulating H1N1 human influenza strain. Furthermore, these infections were associated with severe hemorrhagic pneumonia and the induction of high levels of macrophage-derived cytokines and chemokines, strikingly reminiscent of clinical observations in humans during the Spanish flu pandemic, as well as of recent in vitro and in vivo observations of infections with highly pathogenic avian influenza H5N1 viruses (Cheung et al., 2002; Oxford, 2000; Peiris et al., 2004; To et al., 2001) .	./cache/cord-290352-0pc5eji4.txt	./txt/cord-290352-0pc5eji4.txt