Avian influenza, or bird flu, causes an infectious and contagious respiratory disease. In the lab, several scientists have made the H5N1 strain more contagious, a controversial line of research.
Tom Murphy, 56, in his home in Gainesville, Va., was diagnosed with ALS four years ago. An experimental drug seems to have slowed the progression of his disease, he says, though most ALS patients aren't as lucky.
T.J. Kirkpatrick for NPR
The CDC's director, Tom Frieden, testified before a congressional subcommittee Wednesday regarding a recent anthrax incident and lab safety improvements he is instituting.