World War Z plot from Wiki
The story is told in the form of a series of interviews conducted by the narrator, Max Brooks, an agent of the United Nations Postwar Commission. Although the exact origin of the plague is unknown, a young boy from a village in Chongqing, China is identified as the plague's official patient zero. The plague spreads to various nations by human trafficking, refugees and the black market organ trade. Initially these nations are able to cover up their smaller outbreaks, until a much larger outbreak in South Africa brings the plague to public attention.
Weird notice the city in China??
https://en.wikipedia.org/wiki/World_War_Z