The Centers for Disease Control is investigating three mysterious cases of a bacterial disease that is typically found in tropical climates — yet the infected people have not left the United States. In a health alert posted Wednesday, the CDC said that they are working with the health departments of Kansas, Texas and Minnesota to determine how three people — two adults and one child — contracted melioidosis disease, an infection caused by the Burkholderia pseudomallei bacteria. The first patient to be diagnosed with the disease, in March, died 10 days after being hospitalized, though they had two preexisting conditions,...