Human granulocytic ehrlichiosis (HGE), also called human granulocytic anaplasmosis (HGA), is caused by a bacteria that attacks granuloyctes, a type of white blood cells. HGE is spread by the bite of an infected deer tick. Most cases of HGE in the United States occur in the Northeast, mid-Atlantic, and upper Midwest regions. HGE can occur at any time of the year, with symptoms appearing usually 7 to 14 days after being bitten by an infected tick. Symptoms of HGE include fever, headache, chills, muscle ache, and fatigue. Less common symptoms include abdominal pain, nausea, vomiting, diarrhea, cough, and joint aches. HGE can be treated with antibiotics, but it is important to begin treatment early to prevent potential life-threatening complications from developing.