Wolf Running by Toni Boughton

A woman with no memory wakes to a nightmare. A strange new virus is sweeping the planet, killing millions.

And a vast majority of those that die come back as mindless creatures intent on devouring their prey – humans.

In this desolate new reality there is only one person she can trust; a fellow captive of the ravenous hordes. And when they get separated she will fight both the living and the dead to get back to her friend.
http://www.amazon.com/dp/B00KC0HLGE