Anaplasmosis [A. phagocytophilum]

This code represents an acute febrile illness caused by the bacterium Anaplasma phagocytophilum, transmitted by tick bites. It primarily affects white blood cells, leading to symptoms such as fever, headache, myalgia, and malaise, and can sometimes cause more severe complications like organ failure.

Use this code when documentation confirms a diagnosis of anaplasmosis specifically due to Anaplasma phagocytophilum. This diagnosis is typically supported by laboratory findings such as PCR detection of the organism, serology, or characteristic morulae seen in neutrophils on a peripheral blood smear.

• Ensure the documentation specifies Anaplasma phagocytophilum as the causative agent; other anaplasma species may have different codes.
• Do not confuse with ehrlichiosis, which is caused by a related but distinct group of bacteria.
• Consider sequencing this code as the primary diagnosis when it is the reason for the encounter, and code any associated manifestations or complications secondarily.