dertysAccording to the president of Frontier Airlines, a nurse who was on flights between Dallas and Cleveland and who later tested positive for Ebola may have been at a more advanced stage of the illness than previously thought. Barry Biffle emailed employees Friday about the findings by the Centers for Disease Control and Prevention. He said the CDC has assured the Denver-based airline that crew members on the flights are at a very low risk of exposure. The airline put the pilots and flight attendants on leave for 21 days, which health experts consider the outer limit of how long it would take someone exposed to Ebola to become sick. Yahoo News