390 - Non-invasive Detection of Co-infections in Hospitalized Patients with COVID-19 using the Karius Test, A Plasma-based Next-Generation Sequencing Test for Microbial Cell-free DNA

Background: Patients hospitalized with SARS-CoV2 infections (Covid-19) are frequently febrile and can become critically ill quickly often leading to intervention with antimicrobial therapy. An etiologic diagnosis of superinfections can be difficult to obtain through the usual invasive procedures because of patient instability and the desire to avoid them because they may not be tolerated by the patient. Providers may also be hesitant to embark on such interventions in order to avoid healthcare personnel (HCP) exposure to aerosols.

Methods: Karius Test (KT) results are presented from 30 patients who presented with Covid-19. The KT is a CLIA certified/CAP-accredited next-generation sequencing (NGS) plasma test that detects pathogen cell free DNA (cfDNA). After cfDNA is extracted and NGS performed, human reads are removed and remaining sequences are aligned to a curated database of > 1400 organisms. Organisms present above a statistical threshold are reported.

Results: The KT detected pathogens in the majority of patients (n=20) with COVID-19. The most common infections were herpesviruses in 60% of patients. The most common bacterial pathogen was E. coli seen in 25% of patients. 15 out of 20 patients had more than one pathogen detected. 15% of patients had fungal pathogens, including one detection of Lichtheimia ramosa, in an immunocompromised patient. The results are summarized in the table.Co-infections detected by the Karius Test in patients hospitalized with COVID-19


Conclusion: Open-ended, plasma-based NGS for mcfDNA provides a non-invasive method to assess for co-infections in critically ill patients with COVID-19. This report highlights the potential to increase diagnostic yield as well as to decrease the need for invasive procedures – and their attendant risks to patients and HCP – to obtain etiologic diagnoses to better inform antimicrobial therapy for superinfection. It also serves to highlight the variety of pathogens affecting these patients during the COVID-19 pandemic.