Flu and Parkinson's - how H5N1 bird flu causes neural degeneration in mice

People infected with the bird flu virus - influenza A subtype H5N1 - go through the usual symptoms of fever, aching muscles and cough. The virus is so virulent that 60% of infected humans have died. But according to a study in mice, the infection could also take a more inconspicuous toll on the brain, causing the sorts of damage that could increase the risk of diseases like Parkinson's and Alzheimer's many years after the virus has been cleared.