Human granulocytic anaplasmosis.

Tick-borne infections have been recognized in the United States for more than a century. Patients who present with nonspecific fever after exposure to ticks should be evaluated by clinical examination and routine laboratory testing to determine if the illness is potentially a tick-borne infection. This article focuses on the diagnosis and management of human granulocytic anaplasmosis (HGA) caused by Anaplasma phagocytophilum.