Human ehrlichiosis is caused by the infection of the Ehlichia ewingii or Ehrlichia chaffeensis bacteria. Symptoms include fever, headache, fatigure, confusion, and muscle aches. Additionally, some individuals may develop a rash. Symptom onset is typically within 1-2 weeks of a tick bite. Diagnosis is made by a healthcare professional and is based upon symptoms, clinical presentations, and confirmation of specialized laboratory tests. This disease is preventable through prevention of tick bites. Ehrlichiosis can cause death if left untreated. Individuals who are immune-compromised tend to develop more severe symptoms and have a higher case-fatality rates. Treatment is effective if started early in the course of the diseases. Diagnostic tests may show negative results during the first 7-10 days. When treated with antibiotics within the first five days, symptoms typically subside within 24-72 hours.