A previously healthy 73-year-old male from Delaware presented with a three-day history of generalized fatigue, confusion and high grade fever in mid January. He was found down at home and on initial evaluation was febrile to 39.5° C, tachycardic, and tachypneic. His cardiopulmonary and abdominal exams were unremarkable. He was disoriented but had no focal neurologic deficit. Skin examination revealed no rashes. Laboratory data indicated leukopenia at 3,000, thrombocytopenia at 67,000 and mild transaminitis. His chest x-ray, head computed tomography (CT) and abdominal CT were unrevealing. His urine drug screen, urine culture and blood culture were also negative. A lumbar puncture was considered but not attempted due to severe thrombocytopenia to 18,000 the following day. He was, however, started on empiric antibiotic for meningitis with vancomycin, ceftriaxone, ampicillin and acyclovir. A follow up brain MRI was equally unrevealing.
On hospital day 4, he developed acute hypoxic respiratory failure requiring non-invasive positive pressure ventilation. Chest CT indicated bilateral pulmonary infiltrates. An echocardiogram showed new onset cardiomyopathy with global hypokinesis and an ejection fraction of 35%. Antibiotics were de-escalated to ceftriaxone alone as community-acquired pneumonia was now the leading source. Influenza PCR, Streptococcus pneumonia and legionella urine antigen all came back negative. Further history revealed his hobby as an avid hiker with exposure to ticks. As ceftriaxone got changed to IV doxycycline, the patient’s mental status improved significantly and his fevers subsided. An erlichiosis PCR confirmed Anaplasma phagocytophilum
Discussion:
Human granulocytic anaplasmosis (hga) is a tick-borne illness that is endemic to midwestern and eastern United States. Occurring mostly during summer and spring, cases during the winter are less than five percent of those reported. Although tick -borne illnesses were always on the differential, it was not pursued due the seasonality of his presentation. Understanding that anaplasmosis can occur any month in the year is important in early recognition of the disease. A careful history of tick-exposure, along with telltale signs of fever, leukopenia, thrombocytopenia and transaminitis are key in making the diagnosis.
Conclusions:
We report a rare case of anaplasmosis in the winter month with complication to the heart where prompt treatment led to complete recovery of the patient. Reports of myocardial involvement in anaplasmosis is extremely uncommon yet could become a fatal complication. Treatment should not be delayed for laboratory testing as PCR could be a falsely negative if drawn too early in the disease process. Early diagnosis and treatment, as illustrated in this case, could prevent deterioration of cardiomyopathy, shock and fatality.