Fig. 1

Approximate geographic locations of M. tuberculosis strains sampling sites in Guangxi, China. The fill color of provincial administrative regions of China next to Guangxi is light grey, the color of foreign countries is dark grey. The capitals of countries or provinces have marked by a red square. Red and brown round dots denote the counties in hot spot, green dots indicate cold-spot. Hot spot is a term in geology that referred to M. tuberculosis high incidence rate area and vice versa. The black dot is a county that did not identify as a hot or cold spot in our previous study