id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-344009-hm36pepp	Nathanson, N.	Virus perpetuation in populations: biological variables that determine persistence or eradication	2005		.txt	text/plain	3463	180	46	However, small animal populations can turnover significantly each year, permitting the perpetuation of some viruses that cause acute infections. Measles has several attributes that -in the aggregate -are not seen for other common viral diseases: (i) There are longterm records of measles incidence, collected by many health departments in the United States and other countries; (ii) 95% of all measles infections manifest as illness (in contrast to 1% for poliomyelitis for example); (iii) the symptoms of measles are sufficiently pathognomonic so that it can be distinguished from other viral infections by clinical observers; and (iv) population-wide reports can be corrected for under-reporting (about 15% of measles cases were reported in most cities in the United States prior to the introduction of measles vaccine in 1963). Vaccine-induced reduction of susceptible individuals in such a population can be guesstimated to reduce the number of new infections per trough generation period below the threshold for virus perpetuation.	./cache/cord-344009-hm36pepp.txt	./txt/cord-344009-hm36pepp.txt