REDWOOD CITY, Calif: Karius, a life sciences company that uses metagenomics to rapidly detect over 1,400 pathogens using a simple blood draw, announced new findings that demonstrate the clinical utility of its Karius Test to detect pathogens causing serious infections including those diseases that are difficult to diagnose through conventional methods.
It is important that patients with pneumonia are able to receive a quick diagnosis to begin targeted treatment, but diagnosing pneumonia can be difficult because symptoms vary between patients, many pathogens can cause pneumonia, and once patients start on an antibiotic treatment, it can be difficult to detect the pathogen with routine culture-based methods (or with routine cultures). In addition, the standard culture-based testing method for pneumonia diagnosis can take up to six weeks.
At IDWeek Dr. Georgios Kitsios, Assistant Professor of Medicine at the University of Pittsburgh, will present findings of a clinical research study applying the Karius Test in critically-ill patients with pneumonia in the Intensive Care Unit. The investigators looked at 29 mechanically ventilated adult patients to determine whether the Karius Test could overcome some of the limitations of culture-based testing for pneumonia. The study found that the Karius Test detected pathogens missed by standard culture-based testing in 73% of the cases. The investigators also compared the results of the Karius Test metagenomics in blood samples with metagenomic analyses in respiratory specimens (sputum) taken at the same time, and identified good agreement between the two approaches.
Metagenomic sequencing in plasma and sputum samples showed good concordance between the blood and lung compartments, as well as with culture results in pneumonia patients, said Dr. Kitsios. Especially in cases of aspiration pneumonia, the Karius Test provided evidence of polymicrobial infections, not detected by clinical blood cultures. Further research is needed to evaluate the clinical utility of real-time metagenomics for pneumonia diagnosis and antibiotic guidance in mechanically ventilated patients.
In addition, Dr. John Farrell of OSF Saint Francis Medical Center will present new findings that highlight how diagnostics that use next-generation sequencing, like the Karius Test, can help improve the diagnosis for infectious diseases. The study was done at OSF Saint Francis Medical Center with 42 patients (45 samples) over the course of 90 days. Over the course of the 90-day study period, the infectious-disease team at OSF Saint Francis Medical Center identified four specific clinical scenarios where the Karius Test provided the most value patients with suspected invasive fungal infections; culture-negative endovascular infections/endocarditis; possible discitis or paravertebral infection; and lung disease in patients with Acquired Immunodeficiency Syndrome.
The Karius test provides a more sensitive and less invasive alternative to traditional diagnostic procedures for deep-tissue infections, such as vertebral biopsy of suspected spinal infections, said Dr. Farrell. Use of this technology for the appropriate patient population represents a true win-win since results are available faster than with conventional culture-based diagnostics, and at a fraction of the cost to patients who would otherwise require a diagnostic surgical procedure.
A Karius Test result was available in 44/45 samples. Positive results for one or more pathogens was present in 56. 8% (25/44) of samples. Among positive tests, 56% (14/25) were confirmed by culture, antigen, or PCR. In three of the cases, the Karius Test was the only test that was able to detect the pathogen.
Karius will also present new data that shows the Karius Test's value as a non-invasive alternative for detecting invasive mold infections in immunocompromised patients. A study with Fred Hutchinson Cancer Research Center showed that the Karius Test identified pathogenic molds in 79% (19/24) of subjects with proven non-Aspergillus invasive mold infections, including Mucor, Rhizomucor, Scedosporium, Rhizopus, and Cunninghamella spp.
Additional studies presented at ID Week 2019 include the detection of pathogens in diagnostically challenging cases such as rat lungworm disease, and an application in epidemiology by identifying a cluster of Rickettsia typhi infections in Texas.
Learn more about the six studies that will be presented at ID Week 2019.