Ehrlichia species are bacteria that cause Ehrlichiosis.Ehrlichia bacteria live in a particular type of white blood cell, called monocytes. In the wild, both mice (the same mice that harbor Lyme disease) and white-tailed deer have this bacteria living in their blood. Ticks feed on these hosts, become infected, and then infect humans. The disease often presents with a sudden high fever, fatigue, muscle aches, and headache within a week of having a tick bite. Many of these cases are self-resolving; others require antibiotic treatment. In addition to low white cell counts, low platelet counts, anemia, and liver impairment, and kidney failure can occur. Ehrlichiosis is diagnosed largely on clinical history, including a history of tick bites, fever and symptoms, in addition to laboratory tests that identify the bacteria in white cells. Ehrlichiosis can be a cause of myocarditis.