Secondary and Co-Infections in Patients with COVID-19
The Karius Test is a non-invasive blood test based on next-generation sequencing of microbial cell-free DNA (mcfDNA). Although the Karius Test does not detect SARS-CoV-2, it can identify and quantify pathogens causing secondary infections which may benefit patient outcomes and antimicrobial stewardship during the COVID-19 pandemic.
Severe COVID-19 pneumonia requiring ICU management can be complicated by life-threatening secondary bacterial or fungal infections, some of which may not be clinically suspected.¹
90% of the mcfDNA detected belonged to typical pathogenic bacteria (e.g. E.coli and K. pneumoniae) with the remainder belonging to commensal bacteria (e.g. oral Streptococcus species), fungi (Candida species) and DNA viruses.
The detection of mcfDNA from various pathogens in patients with COVID-19 suggests a high probability of secondary infections.
Diagnosing Infections During the COVID-19 Pandemic
While the Karius Test does not detect SARS-CoV-2, it can non-invasively detect from a single blood sample over 1,000 pathogens causing respiratory or other infections. Karius Test results are typically reported within one day of sample receipt.
Click to learn how the Karius Test can help diagnose infections in each patient scenario.
Garcia-Vidal C, Sanjuan G, Moreno-Garcia E, Puerta-Alcalde P, Garcia-Pouton N, Chumbita M, et al. Incidence of co-infections and superinfections in hospital patients with COVID-19: a retrospective cohort study. Clin Microbiol Infect. 2020. https://doi.org/10.1016/j.cmi.2020.07.041.
Kitsios, G.D., Bain, W., Al-Yousif, N. et al. Plasma microbial cell-free DNA load is associated with mortality in patients with COVID-19. Respir Res 22, 24 (2021). https://doi.org/10.1186/s12931-021-01623-0.
The concentration of the microbial DNA is measured in molecules of DNA fragments per microliter of plasma.
The Karius Test detected respiratory pathogen in 3/4 subjects with no clinical suspicion for secondary infection.
In a study of 15 patients with COVID-19 who were tested for pathogens using the Karius Test, a significant association was found between mcfDNA load and 30-day mortality.² Integration of mcfDNA detection with clinical data provides opportunities for earlier detection of pathogens causing secondary infections, better antibiotic stewardship, and improved patient outcomes.
How the Karius Test can help
Non-survivors had higher total mcfDNA molecules per microliter compared to survivors. (p=0.04)
Non-survivors had a trend for a higher number of organisms detected per sample compared to survivors. (p=0.06)
Concentration of microbial cell-free DNA is measured in molecules of DNA fragments per microliter of plasma (MPM).
Patients with microbiologic confirmation by positive respiratory cultures had high mcfDNA MPMs.
When the Diagnosis is Not COVID-19
Patients with severe COVID-19 infection and those with other infectious diseases may have overlapping clinical presentations. Accurately diagnosing etiologies of pneumonia and fever of unknown origin (FUO) can be a clinical challenge.
How the Karius Test can help
While the Karius Test does not detect SARS-CoV-2, it can non-invasively detect from a single blood sample over 1,000 pathogens causing deep-seated and bloodstream infections.
Examples of pathogens detected by the Karius Test in patients with pneumonia or FUO, but who have been SARS-CoV-2 negative include:
The diagnosis of an alternative respiratory infection does not rule out infection with SARS-CoV-2. When diagnostic testing is negative, the possibility of a false negative result should be considered in the context of a subject’s recent exposures and the presence of clinical signs and symptoms consistent with COVID-19.
A Non-invasive, Broad, Complementary Test
Reduce COVID-19 exposure and transmission risk to healthcare workers from diagnostics such as bronchoscopy or chest CT using the non-invasive Karius Test.
Diagnose infections quickly and accurately to provide appropriate, targeted care.
Stratify patients earlier in the diagnostic workup with a rapid, comprehensive assay to help providers triage patients.
• Fungi including , molds
A Diagnostic Dilemma
Diagnosing infections quickly and accurately is critical.
Karius Test can assist with this diagnostic dilemma by non-invasively detecting bacteria, fungi, and DNA viruses causing respiratory or other infections from a single 5 mL blood sample.
• 1 blood sample
• 1,000+ DNA pathogens
• 1 day turnaround time*
Karius Test Results
Behind the Data
New study on identifying secondary infections in patients with COVID-19
Click to learn more.
• Nocardia spp
• Mycobacte riaspp
• Fungi including Candida, Aspergillus, molds
Bronchoscopy? Cultures? PCR?
What else is on the differential?
Is the patient truly
Order the Karius Test
Order the Karius Test
1. Can the Karius Test detect SARS-CoV-2?
Frequently Asked Questions
No. The Karius Test cannot detect RNA viruses such as SARS-CoV-2. The list of 1,000+ detectable pathogens can be found here: kariusdx.com/pathogenlist.
2. Does a positive Karius Test result rule out COVID-19?
No. The diagnosis of an alternative respiratory infection does not rule out infection with SARS-CoV-2. As with any diagnostic test, the Karius Test results should be interpreted within the context of clinical data, including patient history, physical findings, epidemiological risk factors, and other laboratory data.
Our Medical Affairs team of infectious diseases physicians is available for consultation. Please contact Medical Affairs at email@example.com or 866-452-7487.
3. Does prior antimicrobial therapy influence Karius Test results?
The Karius Test can detect cell-free DNA (cfDNA) from dead and dying pathogens released into the bloodstream. Therefore, the cfDNA signal of a pathogen may still be detected even when a patient has been pre-treated with antibiotics.
4. What is the Karius Test process?
The Karius Test is a simple and efficient process. One 5 mL blood sample should be collected in a plasma preparation tube (PPT), centrifuged at your hospital, and then shipped overnight to Karius. Karius Test kits, which include collection tubes and shipping supplies, are supplied by Karius. Results are typically reported one day after sample receipt.
For additional questions, please contact Karius Customer Support (Phone: 866-452-7487 | Email: firstname.lastname@example.org).
We are available 24/7.
This test was developed and its performance characteristics determined by Karius. This test has not been cleared or approved by the FDA, nor is it required to be. The Karius laboratory is certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA ‘88) and is accredited by the College of American Pathologists (CAP) to perform high-complexity clinical laboratory testing.
• Endemic mycoses