While cases of bird flu in humans have steadily climbed since last fall, health officials maintain the risk to humans is low

A Canadian teenager infected with the H5N1 bird flu in November has fully recovered, but scientists are worried about mutations in the virus that can increase its ability to bind to human cells, causing deadlier diseases.

In light of the ongoing global spread of the H5N1 avian influenza, U.S. public health experts are reassured that current treatments and vaccines are effective against severe disease. The virus, which has caused sporadic human cases,