Case Presentation: Anaplasmosis phagocytophilum is a rare, emerging tick borne illness transmitted by the Ixodes Scapularis tick endemic to the North Central and Northeastern United States. With an incidence of 6.1 cases per million in 2010, patients often present with nonspecific symptoms such as fever, leukopenia, thrombocytopenia, and transamintis. Cases outside of endemic areas are rare and easily missed. We report on a patient in the Southern United States posing diagnostic challenges to this rare illness.
Discussion: A 60-year-old male presented to a Florida Emergency Department with fever, malaise, productive cough, loss of appetite, recent fall, and increasing muscle weakness for three days. His social history was significant for tobacco and alcohol abuse. Three weeks prior to presentation, patient was at an RV camp in upstate New York. He denied sick contacts, animal bites or new rashes.
Initial workup revealed a fever of 40.1o C, WBC count of 2,300 cells/uL, a platelet count of 50,000 cells/uL,and elevated liver enzymes (AST:271 units/L, ALT:137 units/L. CT scan of the head and neck demonstrated chronic sinusitis and a chest X-ray further revealed hyper-aeration. From our initial evaluation, we concluded that this patient may have sepsis secondary to community acquired pneumonia and liver failure secondary to alcohol abuse.
The patient was started on broad spectrum antibiotics on admission, however, despite treatment his symptoms worsened and his WBC count and platelet counts dropped to 900 cells/uL and 35,000 cells/uL respectively. Despite no evidence of bites or rash, the patient’s recent travel history prompted us to order a hepatitis panel, tick-borne illness panel, and a peripheral blood smear. Doxycycline was also started empirically. On day three, the patient’s symptoms resolved and his white blood cell count increased to 2,100 cells/uL and continued to trend upward.
All the patient’s lab testing came back negative. Peripheral blood smear results showed no intracytoplasmic inclusion bodies. With high clinical suspicion, we then ordered tests for Anaplasmosis phagocytophilum, the only tick borne PCR not available in our hospital which returned positive confirming the diagnosis. The patient was discharged home on oral Doxycycline with follow up with an infectious disease specialist.
Conclusions: Anaplasmosis phagocytophilum is a difficult diagnosis in patients who present with sepsis in non-endemic areas. With the increase of travel, and southern states presenting as havens for Northern residents in the wintertime, tick borne illnesses should be high on the list of differential diagnoses. While A. phagocytophilum is rare, delay in care can lead to dramatic decline in susceptible patients and life-threatening complications. We recommend that doxycycline should be considered in empiric treatment of septic patients with transaminitis, leukopenia, and thrombocytopenia and test for Anaplasmosis phagocytophilum in addition to other tick borne illnesses especially in those with a travel history to endemic areas.