COVID-19 - Laboratory Testing in the United States

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Apr 08, 2020
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In response to the COVID-19 outbreak, the CDC developed a test kit called the “Centers for Disease Control and Prevention (CDC) 2019-Novel Coronavirus (2019-nCoV) Real-Time Reverse Transcriptase (RT)-PCR Diagnostic Panel.” This test kit is used for upper and lower respiratory samples only. 

The CDC recommends testing an upper respiratory specimen for initial COVID-19 testing via nasopharyngeal swab.  When this is not possible, the CDC recommends the following alternatives:

  • An oropharyngeal (OP) specimen collected by a healthcare professional, or
  • A nasal mid-turbinate (NMT) swab collected by a healthcare professional or by onsite self-collection (using a flocked tapered swab), or
  • An anterior nares specimen collected by a healthcare professional or by onsite self-collection (using a round foam swab).

The CDC also recommends testing specimens from the lower respiratory tract, if available, but sputum should not be induced. 

According to the Centers for Disease Control (CDC), in conjunction with the Association of Public Health Laboratories (APHL), a total of 95 laboratories across the United States are currently using this diagnostic test.  Currently, a serologic test is not available, but is under development.

On March 27, the FDA granted emergency authorization for laboratories to being using a new rapid COVID-19 test produced by Abbott Diagnostics that could provide results in less than 15 minutes. Details regarding timing of production and distribution are expected to be forthcoming.

Due to the vague symptomatology associated with COVID-19, it can often be difficult to know which patients should be tested. Clinicians must use their clinical judgement along with careful history taking to determine if a patient has signs and symptoms compatible with COVID-19.  The CDC reports that most patients with confirmed COVID-19 have had either objective or subjective fever with symptoms of acute respiratory illness (e.g., cough, difficulty breathing). 

The CDC strongly encourages providers to test for other causes of respiratory illnesses, as the differential diagnosis is broad. The clinician should consider performing a respiratory pathogen panel to assess for other respiratory pathogens.

According to the CDC, patient priorities for testing may include:

  • Hospitalized patients who have signs and symptoms compatible with COVID-19 in order to inform decisions related to infection control.
  • Other symptomatic individuals such as older adults and individuals with chronic medical conditions and/or an immunocompromised state that may put them at higher risk for poor outcomes (e.g., diabetes, heart disease, receiving immunosuppressive medications, chronic lung disease, chronic kidney disease).
  • Any persons, including healthcare personnel, who have had close contact with a suspected or laboratory-confirmed COVID-19 patient or who have a history of travel from affected geographic areas within 14 days of their symptom onset.

The CDC also notes that documented COVID-19 infections in a jurisdiction and known community transmission may contribute to an epidemiologic risk assessment to inform testing decisions.  

Additionally, the CDC provides guidelines for Collecting, Handling, and Testing Clinical Specimens from Persons Under Investigation (PUIs) and encourages healthcare workers to use EPA-registered hospital disinfectants with label claims to be effective against SARS-CoV-2 (the virus that causes COVID-19).  The CDC has posted supplemental guidance regarding specimen collection, storage, and shipping to CDC laboratories.

For more detailed information on the CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel, the CDC has provided extensive FDA-authorized instructions for use which contains information about the test, its intended use, test procedure and performance characteristics.  The CDC website also provides the FDA Letter of Authorization for the diagnostic panel. The CDC also provides standard operating procedure for public health labs to create their own viral transport media pdf icon[5 pages] in accordance with the CDC’s protocol. For other detailed information and other frequently asked laboratory questions regarding diagnostic tools and the CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel, please visit the CDC page here.

Go to the profile of Julie Grishaw, ACNP

Julie Grishaw, ACNP

Senior Editor, McGraw-Hill Education

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