Severe Fatal ARDS Due to Untreated Human Granulocytic Anaplasmosis in a 67-Year-Old Man: A Case Report

BACKGROUND Anaplasmosis, or human granulocytic anaplasmosis (HGA), is a tick-borne diseased caused by a gram-negative, intracellular bacterium, Anaplasma phagocytophilum. HGA usually presents with mild symptoms but can be more severe. This report describes a 67-year-old male resident of rural Pennsylvania, admitted to the hospital after a fall, who developed fatal acute respiratory distress syndrome (ARDS) associated with human granulocytic anaplasmosis (HGA) following transmission of Anaplasma phagocytophilum by a tick bite (Ixodes scapularis). CASE REPORT A 67-year-old man, resident of rural Pennsylvania, with history of diabetes mellitus, presented after falling from a 7-foot-tall ladder, sustaining right-sided hemopneumothorax, multiple right rib fractures, and unstable T12 vertebra fracture. He required tube thoracostomy and underwent T9-L2 posterior spinal fusion surgery. His initial labs showed leukopenia, thrombocytopenia, and elevated transaminase levels. His course was complicated by cardiac arrest and acute respiratory failure, consistent with severe ARDS. He received high positive end-expiratory pressure (PEEP) ventilation, prone positioning, and neuromuscular paralysis to improve refractory hypoxemia. Bronchoalveolar lavage (BAL) for bacterial, fungal, viral pathogens, Covid-19, respiratory viral panel, Mycoplasma pneumoniae, and Chlamydia pneumoniae were negative. his family withdrew medical care, knowing the patient's own wishes, and the patient died. Polymerase chain reaction (PCR) for Anaplasma DNA came back positive after the patient's death. His peripheral smear was then examined, showing morulae inside the cytoplasm of infected neutrophils.   CONCLUSIONS This report describes the atypical presentation of a case of HGA and highlights that in parts of the world where tick-borne diseases are endemic, disease awareness, high index of clinical suspicion, and early diagnosis and management are required.