Grosse Point Woods Anaplasmosis: Anaplasmosis previously known as HGE, is an illness caused by the bacterium Anaplasma phagocytophilum carried by black-legged ticks, aka deer ticks. Anaplasmosis previously known as HGE, is an illness caused by the bacterium Anaplasma phagocytophilum carried by black-legged ticks, aka deer ticks.