H5N1 influenza--continuing evolution and spread.

We don't know whether the next influenza pandemic will be caused by the H5N1 avian influenza virus. But Drs. Robert Webster and Elena Govorkova write that given the number of cases of H5N1 influenza that have occurred in humans to date (251) and the rate of death of more than 50%, it would be prudent to develop robust plans for dealing with such a pandemic.