Diagnostic Tools and Virus: Questions and Answers

Updated April 2, 2020

The diagnostic panel’s Food and Drug Administration (FDA)-authorized instructions for useexternal iconexternal icon contain information about the test, its intended use, test procedure and performance characteristics.  FDA’s EUA websiteexternal iconexternal icon has published the FDA Letter of Authorizationexternal iconexternal icon for the diagnostic panel. the authorization letter defines the authorized use and the conditions of authorization that apply to CDC and to testing laboratories.

The International Reagent Resource (IRR)external iconexternal icon will distribute the diagnostic panel and most of the associated reagents to registered state and local public health labs. During this emergency response to COVID-19, CDC is deferring the decision to authorize new county or city laboratories to their state public health laboratory. Laboratories that meet these criteria may request registration at CDC’s IRR.

CDC has also posted a list of commercially available lots of primer and probe setspdf iconpdf icon that have passed CDC functional quality control and may be used with the CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel.

The Food and Drug Administration (FDA) authorized the Emergency Use Authorization (EUA) on February 4, 2020.

  • CDC’s diagnostic panel is intended for use by state and local public health laboratories designated by CDC as qualified, and in the United States, certified under the Clinical Laboratory Improvement Amendments (CLIA) to perform high complexity tests. This includes U.S. state and local public health laboratories and Department of Defense (DoD) laboratories.
  • Each laboratory that places an order will receive one diagnostic panel initially, and each panel can test 700-800 patient specimens.

This is a picture of CDC’s laboratory test kit for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). CDC tests are provided to U.S. state and local public health laboratories, Department of Defense (DoD) laboratories.

This is a picture of CDC’s laboratory test kit for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). CDC tests are provided to U.S. state and local public health laboratories, Department of Defense (DoD) laboratories.

The CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel contains the following:

  • 2019-nCoV_N1, 2019-nCoV_N2 and 2019-nCoV_N3 primers and probes that target the nucleocapsid (N) gene and are designed for both universal detection of SARS-like coronaviruses as well as specific detection of the 2019-nCoV;
  • RP primers and probes that target the Human RNase P gene; and
  • nCoVPC, the 2019-nCoV positive control used in the assay.

The CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel also requires the use of additional authorized materials and authorized ancillary reagents that are not included with the test but are commonly used in clinical laboratories. They are described in the authorized CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel Instructions for Use Package Insert.

The CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel requires the control materials, or other authorized control materials listed below. All of these controls must generate expected results for a test to be considered valid, as outlined in the CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel Instructions for Use.

  • Human Specimen Control (HSC): A human cell culture preparation used as an extraction control and positive control for the RNase P primer and probe set that is extracted and tested concurrently with each specimen extraction run.
  • Positive Control for COVID-19 (nCoVPC): Run with each batch of specimens.  Monitors for failures of rRT-PCR reagents and reaction conditions.
  • No Template Control (NTC): Nuclease-free water included in each run.  Monitors for reagent and system contamination.

Clinicians should base their decisions on whether a patient should be tested for COVID-19 on:

  • Signs and symptoms,
  • Local epidemiology, and
  • If the patient has had close contact with a confirmed COVID-19 patient or a history of travel from an area with sustained transmission within 14 days of symptom onset.
  • Clinicians should consider that recent studies indicate that people who are infected but do not have symptoms likely also play a role in the spread of COVID-19.

Clinicians are encouraged to test for other causes of respiratory illness in addition to COVID-19. More details on clinical characteristics of COVID-19 are found on Evaluating and Reporting Persons Under Investigation.

Use appropriate personal protective equipment when collecting and handling specimens from individuals suspected of being infected with COVID-19, as outlined in the CDC Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens From Persons for Coronavirus Disease 2019 (COVID-19).

The National Institute of Health (NIH)’s Biodefense and Emerging Infections Research Resources Repositoryexternal iconexternal icon (BEI Resources) will provide laboratories with SARS CoV-2 samples.

The Biomedical Advanced Research and Development Authority (BARDA) in the U.S. Department of Health and Human Services (HHS) is providing a web portal to support U.S. government medical countermeasure research and development. Interested stakeholders can learn more here.external iconexternal icon