Abstract Title: Navigating Anaplasmosis: A Case Report Highlighting Diagnosis and Treatment Background: Human Granulocytic Anaplasmosis caused by Anaplasma phagocytophilum is an emerging concern in the United States, spread by Ixodes scapularis and Ixodes pacificus in the Northeastern and Midwestern regions and in the Western regions, respectively. Tick-borne infections are increasingly reported during the summer months, especially in Pennsylvania. Lyme disease remains the most reported tick-borne illness in the state. Anaplasmosis presents unique challenges due to its nonspecific clinical manifestations and potential to mimic other tick-borne diseases. Preventing tick bites prevents the spread of infections. Case Presentation: The case of a 68-year-old male patient highlights the critical importance of recognizing and diagnosing anaplasmosis promptly. He presented to the ED with sudden onset high-grade fevers at 103°F, chills, abdominal pain with nausea and vomiting, and generalized weakness. His heart rate was 105/min and BP was 146/87 mm Hg. Fever panel was negative. With alarming findings such as profound thrombocytopenia (platelets decreasing from 102 K/mcL to 56 K/mcL within a day), transaminitis, and elevated CRP levels at 322.1 mg/dL, admission for suspected sepsis of unclear origin was necessitated. Empirical treatment with IV Doxycycline, Atovaquone, and Azithromycin was initiated to cover potential tick-borne infections. Radiological investigations, including CT scans and echocardiography, were unremarkable, further complicating the diagnostic process. The patient's history of living in wooded areas, owning dogs, and previous deer rearing raised suspicion for a tick-borne illness, despite no recollection of a recent tick bite. Definitive diagnosis was achieved through a tick-borne PCR panel, which confirmed Anaplasma phagocytophilum infection. This gram-negative intracellular bacterium selectively infects neutrophils, leading to the characteristic intracytoplasmic inclusions known as morulae, observed on peripheral blood smear. Given the patient's old age, he was at increased risk for severe complications such as systemic inflammatory response syndrome and multiorgan failure. Following a five-day course of IV Doxycycline, the patient's clinical status improved with resolution of fever and thrombocytopenia. He was discharged on oral Doxycycline and Atovaquone, emphasizing the importance of timely intervention and appropriate antimicrobial therapy in managing anaplasmosis. Discussion: This case underscores the challenges in diagnosing tick-borne illnesses, particularly in non-endemic regions with limited awareness. Heightened clinical suspicion due to drastic thrombocytopenia, prompt empirical treatment, and utilization of specific diagnostic tools such as NAAT/Tick-borne PCR panels are crucial in achieving favorable patient outcomes. Early recognition of clinically compatible symptoms associated with thrombocytopenia remains paramount in combating the rising incidence of tick-borne infections across the United States.