Chloropleth Maps

Chloropeth maps are used to express spatial units with uniform colors and patterns. They are appropriate for scaled data such as the new cases of T. brucei gambiense in Africa in 2006. The colors represent the varying prevalence categories of the disease as given by the key. T. brucei is the protozoa that causes sleeping sickness or African Trypanosomiasis. The vector is the tsetse fly, which prefers shady river areas. The symptoms include confusion, altered diurnal rhythm, dementia, and convulsions. The victim becomes progressively  mentally impaired, loses bladder control, and may undergo varying forms of paralysis eventually fading into a coma.