id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-023488-jf2xl3vl	Le Duc, James W.	Emerging Viral Diseases: Why We Need to Worry about Bats, Camels, and Airplanes	2016-02-12		.txt	text/plain	9385	464	49	On occasion, a virus that is already widespread in a population can emerge as a cause of epidemic or endemic disease, due to an increase in the ratio of cases to infections. Although many zoonotic viruses can be transmitted to humans on occasion, their relative ability to spread from human to human determines whether or not they emerge as significant new virus diseases of mankind (Table 2 ). In the history of modern virology (the last 50 years) there are very few documented instances where zoonotic viruses have established themselves in the human population and emerged as new viral diseases of mankind (Table 2 ). Rarely, as in the case of HIV, SARS coronavirus, and Ebola filovirus, a zoonotic virus becomes established in humans, causing a disease that is truly new to the human species.	./cache/cord-023488-jf2xl3vl.txt	./txt/cord-023488-jf2xl3vl.txt