Figure. Geographic distribution of the 4 most common strains defined by restriction fragment length polymorphism: A) strain kps12, B) strain kps121, C) strain kps41, and D) strain kps44. Each o represents a patient. Each square is 10 km × 10 km. The background shading represents the total number of tuberculosis (TB) cases in each area during the study period, which largely reflects the population density.