Case Presentation: This is a 38 year old male with a past medical history of hypertension, hyperlipidemia, bipolar disorder and alcohol abuse who was brought to the emergency room after he collapsed on the subway in May 2018. Several days prior to this episode, he reported cyclical fevers to a maximum of 102F, myalgias and lethargy with an otherwise negative review of systems. His social history was positive for recent travel to India without taking malaria prophylaxis and he was released from a detoxification unit the Berkshires two weeks prior. He admitted to hiking in the woods daily at the Berkshires (Upstate NY), but was adamant that he checked himself daily for ticks without any positive findings. In the emergency room, he was afebrile but hypotensive which resolved with fluid admiration. Blood work was significant for acute kidney injury (creatinine of 1.83 mg/dL), transaminitis (AST/ALT of 81/99 U/L) and pancytopenia. He was started on broad spectrum antibiotics (Cefepime/Vancomycin) for a presumed bacterial infection and admitted to medicine. The initial fever workup including blood cultures, chest x-ray, urinalysis and a blood parasite smear were unremarkable. The patient continued to be febrile throughout the night of the admission to a temperature maximum of 101F. The infectious disease service was consulted in the morning and his antibiotics were narrowed to Doxycline for presumed Anaplasmosis infection based on his travel history, transaminases, pancytopenia with an otherwise negative workup. Upon the start of the Doxycycline, he remained afebrile and was discharged the next day. PCR testing confirmed Anaplasmosis after his discharge.

Discussion: Anaplasmosis is a tick-borne infection caused by Anaplasma phagocytophilum. Symptoms of anaplasmosis include febrile flu-like illness, nausea, vomiting and abdominal pain. These symptoms often present five to fifteen days after a tick and most commonly transmitted in the spring and summer months. Laboratory abnormalities associated with infected patients include abnormal liver function tests and bone marrow suppression. This patient presented with a flu-like illness and was subsequently found to have a profound transaminitis and pancytopenia. He had an otherwise negative review of symptoms aside from his travel history and lack of prophylaxis toward malaria. He never complained of a rash and did frequent skin exams for ticks during his stay in the Berkshires. This history can skew medical providers as 25% of patients report no known history of a tick bite. However, the hallmark of this tick-borne illness is lack of rash (found only in approximately 10% of patients with anaplasmosis). He also had pancytopenia which can be seen in multiple tick-borne infections but his elevated transaminases are a hallmark of anaplasmosis in the domain of tick-borne illnesses. The treatment of anaplasmosis is the Doxycycline for 10 days or for three to five days after defervescence, whichever is longer. Within a day of the Doxycycline initiation, the patient’s condition significantly improved.

Conclusions: Anaplasmosis is a tick-borne illness that is often associated with spring and summertime fevers, liver function abnormalities and bone marrow suppression. It is important to start treatment upon suspicion of this illness to prevent morbidity and mortality associated with delayed diagnosis.