Resistance to anti-flu drugs has risen by 12 percent worldwide in the past decade, scientists said on Thursday in a finding that could pose problems for health officials trying to avert a pandemic.Researchers at the Centers for Disease Control and Prevention (CDC) in Atlanta found resistance to a class of drugs used to treat influenza for more than 30 years rose from 0.4 percent in 1994-1995 to 12.3 percent by 2004.In some countries in Asia, where scientists suspect the next strain of flu with pandemic potential will originate, drug resistance exceeded 70 percent.
