Tick-borne infections were first formally recognized over a century ago, but it was only in 1990 that the first case of human granulocytic anaplasmosis (HGA), a tick-borne infection caused by Anaplasma phagocytophilum, was identified.1,2 Like other tick-borne infections, HGA presents as a nonspecific febrile illness. The most common clinical features are fever, headache, myalgia and malaise.2 This case report presents a rare but serious complication of HGA – acute respiratory distress syndrome (ARDS).


A 49-year-old female with no past medical history presented to her local emergency department with complaints of fevers, headache, neck pain, myalgia, and malaise. She denied symptoms of upper respiratory tract infection, diarrhea, dysuria, rashes, and bleeding or bruising. She worked as an administrative assistant and lived on a farm in a rural area of Pennsylvania. She was in a monogamous relationship. She drank alcohol socially, and she was not known to use any illicit drugs.

Her vital signs were temperature of 102 degrees Fahrenheit, pulse of 100 beats per minute, oxygen saturation of 98% on room air, and respiratory rate of 18 breaths per minute. On physical examination, she appeared fatigued but was alert and oriented to person, place, and time. There were no focal neurologic deficits. Her oropharynx was clear. Her neck was supple with full range of motion. Brudzinski and Kernig test were negative. Her lungs were clear to auscultation. Cardiac exam revealed tachycardia but no murmurs, rubs, or gallops. Her abdomen was soft and non-tender. There were no stigmata of liver disease. She had no rashes and no cutaneous bleeding. There were no palpable lymph nodes.

Laboratory evaluation revealed a white blood cell count of 2 x109/L (normal range = 4-11 x109/L), platelet count of 43 x109/L (normal range = 140-400 x109/L), and hemoglobin of 11 g/dL (normal range = 14-17 g/dL). Her liver function panel revealed an aspartate aminotransferase (AST) of 923 U/L (normal range = 7-42 U/L) and alanine aminotransferase (ALT) of 946 U/L (normal range = 1-45 U/L). Her bilirubin and alkaline phosphatase were mildly elevated. The patient was admitted for Systemic Inflammatory Response Syndrome (SIRS). She was empirically started on vancomycin and piperacillin-tazobactam. On her first day of admission she developed hypoxemic respiratory failure. A chest x-ray showed bilateral airspace opacities without evidence of volume overload. Mechanical ventilation was initiated and doxycycline was added. She was transferred to Thomas Jefferson University Hospital for management of ARDS.