We Are Here to Support You | Karius

We are here to support you during the COVID-19 pandemic.


How the Karius® Test can help

Patients with severe COVID-19 infection and those with other infectious diseases may have overlapping clinical presentations. This is a particular clinical challenge for accurately diagnosing etiologies of pneumonia and FUO.

While the Karius Test does not detect SARS-CoV-2, it can non-invasively detect from a single blood sample over 1,000 pathogens (DNA viruses, bacteria, fungi, and parasites) causing infections. Clinicians can potentially stratify patients earlier in the diagnostic workup and mitigate exposure and transmission risks from invasive procedures.


When a SARS-CoV-2 test comes back negative


When the SARS-CoV-2 test result is negative, many patients undergo repeated SARS-CoV-2 testing to ensure that they are truly negative. Repeated testing poses some transmission risk to healthcare workers. Additionally, a negative SARS-CoV-2 test poses a diagnostic dilemma for clinicians. Due to limited resources during the pandemic and the SARS-CoV-2 transmission risk for invasive procedures such as bronchoscopy, diagnosing infections quickly and accurately is critical.


Examples of pathogens detected in patients with pneumonia or FUO, but who have been SARS-CoV-2 negative include:

  • Pneumocystis jirovecii
  • Legionella spp
  • Nocardia spp
  • Endemic mycoses


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.


Karius Test


Clinical Partnerships



Investigating secondary infections in patients with COVID-19 and the impact on disease severity, disease progression, and mortality

Karius is pursuing partnerships with leading institutions that have established COVID-19 research programs to evaluate the association between secondary infections and outcomes in patients with COVID-19, with a focus on patients with severe illness.

For more information on this clinical partnerships, contact us at medical@kariusdx.com.


Perspective on
Secondary Infections


Helping Healthcare Providers


  • Provide appropriate targeted care

  • Free up hospital & laboratory resources

  • Non-invasively evaluate for infections


Click below to learn more about anticipated benefits of the Karius Test during the COVID-19 pandemic.



    Karius® Test


    The Karius Test is a non-invasive blood test based on next-generation sequencing of microbial cell-free DNA that can detect both deep-seated and bloodstream infections. It can identify and quantify over 1,000 clinically relevant pathogens including bacteria, fungi, DNA viruses, and parasites. The Karius Test cannot detect RNA viruses such as SARS-CoV-2.The Karius Test has demonstrated success in diagnosing various infections including complicated pneumonia, infections in immunocompromised patients, and endocarditis.1,2,3


    The Karius Test is a laboratory service performed at our CLIA-certified and CAP-accredited lab in Redwood City, CA.a 




    blood sample





    DNA pathogens



    1 day

    turnaround timeb


    View Clinical Data


    Frequently Asked Questions


    1. Can the Karius Test detect SARS-CoV-2? 

      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.


    1. 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 medical@kariusdx.com or 866-452-7487.


    1. 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


    1. 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.


    1. How will my institution receive the Karius Test result?

      All Karius Test results are faxed to the fax number provided during account setup. Additionally, test results can be accessed via online portal or SMS. Please call Karius Customer Support for assistance with these alternative methods of receiving test results.


    For additional questions, please contact Karius Customer Support (Phone: 866-452-7487 | Email: help@kariusdx.com). We are available 24/7.

    a 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.
    b More than 85% of specimens received by 8:30 am (PT) Monday through Saturday will have results that are reported the next day, subject to lab capacity issues as mentioned above. 


    1 Farnaes L, et al. Diagn Microbiol Infect Dis 2019;94(2):188-191. doi: 10.1016/j.diagmicrobio.2018.12.016
    2 Rossoff J, et al. Open Forum Infect Dis 2019;6(8):ofz327. doi: 10.1093/ofid/ofz327
    3 Downey R, et al. J Pediat Inf Dis Soc 2020. piaa014. doi:  10.1093/jpids/piaa014