Ehrlichiosis is an umbrella term for the diseases caused by the bacteria Ehrlichia chaffeensis, E. ewingii, or E. muris eauclairensis. Spread by both the black-legged tick and lone star tick, symptoms include fever, chills, muscle aches, headache, and upset stomach. Transmission by blood transfusion and organ transplant have also occurred. About one-third of people develop a rash that begins five days after the onset of fever and appears as either red splotches or dots. Late-stage ehrlichiosis can cause inflammation of the brain and surrounding tissue (meningoencephalitis), uncontrolled bleeding, and respiratory or organ failure.