Tooth and Nail by Craig DiLouie

As a new plague related to the rabies virus infects millions, America recalls its military forces from around the world to safeguard hospitals and other vital buildings. Many of the victims become rabid and violent but are easily controlled-that is, until so many are infected that they begin to run amok, spreading slaughter and disease. Lieutenant Todd Bowman got his unit through the horrors of combat in Iraq. Now he must lead his men across New York through a storm of violence to secure a research facility that may hold a cure. To succeed in this mission to help save what's left of society, the men of Second Platoon will face a terrifying battle of survival against the very people they have sworn to protect-people turned into a fearless, endless horde armed solely with tooth and nail.