Zone One by Colson Whitehead
From the author of the Man Booker Longlisted 'The Underground Railroad'.
A pandemic has devastated the planet, sorting humanity into two types: the uninfected and the infected, the living and the living dead. The worst of the plague is now past, and Manhattan is slowly being resettled. Armed forces have successfully reclaimed the island south of Canal Street - aka 'Zone One' and teams of civilian volunteers are clearing out the remaining infected 'stragglers'.
Mark Spitz is a member of one of these task forces and over three surreal days, he undertakes the mundane mission of malfunctioning zombie removal, the rigours of Post-Apocalyptic Stress Disorder, and attempting to come to terms with a fallen world. But then things start to go terribly wrong...