Abstract Introduction Karius testing uses metagenomic sequencing to identify microbial cell-free DNA. It can identify a broad range of bacterial, viral, fungal, and parasitic organisms with a rapid turnaround time of about 48 hours. It has been shown to guide therapy for patients with clinical sepsis but without positive culture data and to promote antibiotic narrowing for patients with febrile neutropenia. We present a patient who had multi-system organ dysfunction in the setting of septic shock, despite initially inconclusive culture data, and whose fungal sinusitis was not identified prior to Karius testing. Case Presentation The patient is a 58-year-old man with a history of hypertension, HIV (viral load undetectable), major depressive disorder, and polysubstance use disorder who presented initially with encephalopathy in the setting of a urine toxicology screen that was positive for amphetamines. He developed rhabdomyolysis, acute kidney injury, ileus, coagulopathy, and presumed septic shock, although cultures were unrevealing, requiring transfer of care to the ICU. His course subsequently was complicated by cardiac arrest, massive hemolysis, and Stenotrophomonas maltophilia pneumonia. Despite nasogastric tube suction and administration of rectal vancomycin and intravenous metronidazole, vancomycin, meropenem, micafungin, doxycycline, and trimethoprim/sulfamethoxazole, the patient remained in shock, with normal cardiac function on echocardiography, so a Karius test was performed. It returned positive for Mucor and Rhizopus species and Herpes simplex virus (HSV) 1. In light of air-fluid levels in the maxillary sinus identified noted on a head CT performed early in his hospital course, the patient underwent urgent rhinoscopy with identification of mold and subsequent surgical resection of infected tissue. Systemic amphotericin, isavuconazole, and acyclovir, and intranasal amphotericin, were initiated. His course further was complicated by development of acalculous cholecystitis, respiratory infection with Pseudomonas putida, and disseminated necrotic wounds with biopsy findings that were concerning for superimposed infection with both Pseudomonas and Mucor species. Additional surgical debridement was not consistent with the goals of care of the patient. In the setting of worsening shock, his care was transitioned to comfort measures only, and he expired. Discussion Although this patient ultimately did succumb to his critical illness, Karius testing was key to securing the diagnoses of fungal sinusitis and HSV infection in this patient without evident immunosuppression or uncontrolled diabetes mellitus. Future research should seek to identify how Karius testing influences the outcomes of patients in the ICU and to provide guidance about how to incorporate this testing into routine clinical practice. This abstract is funded by: None
Smith et al. (Fri,) studied this question.