Point of Care Testing for COVID-19

Created 7/30/2020; Updated 9/21/2020

Overview

Testing at the point-of-care (POC) for COVID-19 adds a distinct advantage—rapid availability of results upon which to make treatment and infection prevention and control decisions. The clinical performance of POC tests depend on the circumstances in which they are used and how carefully the test is performed. They need to be performed correctly, by trained personnel and in an environment where good laboratory practices are followed. In addition, the clinical status (e.g., symptomatic, exposed) of individuals being tested also needs to be considered when performing and interpreting the results of these tests. Reporting of results to Pennsylvania's electronic disease surveillance system, PA-NEDSS is mandated by law and becomes the responsibility of the facility doing the testing.

Types of Tests

At present, the U.S. Food and Drug Administration (FDA) has issued Emergency Use Authorization (EUA) for POC testing for COVID-19 via two types of tests: molecular detection and antigen detection.

Molecular detection tests use nucleic acid amplification technology (NAAT) for the qualitative detection of viral nucleic acids found in the RNA of the target virus. This is the same technology used by most clinical laboratories to detect SARS-CoV-2, the virus that causes COVID-19. This type of test has high sensitivity and specificity, but test performance varies by manufacturer and depends on proper specimen collection.

Antigen detection tests will react to the detection of nucleocapsid antigens. These antigens are generally detectable in the respiratory system during the acute stage of infection. Antigen tests are very specific but not as sensitive as molecular detection tests. This means that a positive antigen test is highly accurate, but there is a greater chance of false-negative results (i.e. a person who is infected will still test negative) with this test type.

POC testing can be used for diagnostic purposes or for screening. Testing is considered diagnostic when used to identify current infection in a person who has signs or symptoms consistent with COVID-19, or when a person is asymptomatic but has recent known or suspected exposure to SARS-CoV-2. Testing is considered screening when used for persons who are asymptomatic and do not have known or suspected exposure to SARS-CoV-2.

The performance of these tests is dependent on pretest probability. Pre-test probability is the chance that the patient has the disease, estimated before the test result is known. Pretest probability should be informed by using a rolling average of the positivity rate over the previous 7-10 days along with clinical context. Pretest probability needs to be considered when interpreting the results of these tests.

Specimen Collection

Each POC test uses a different method of specimen collection and storage. Carefully follow the Instructions for Use (IFU) for the instrument. Don all required personal protective equipment per PA-HAN-524 including a respirator or a facemask (if respirator is not available), eye protection, clean gown and clean gloves prior to specimen collection. Remove gloves, perform hand hygiene, and don clean gloves between collection or handling of each specimen.

All testing for SARS-CoV-2, including rapid antigen testing, is directly impacted by the integrity of the specimen, which depends on specimen collection and handling. Improper specimen collection may cause some swabs to have limited amounts of viral genetic or antigenic material for detection. Inadequate quality assurance procedures could result in cross contamination of the specimen, which could cause inaccurate test results. Delays from sample collection to testing should be minimized.

Plan and prepare a method for specimen collection and handling that minimizes the potential for specimen contamination, which can occur from specimen-to-specimen or from the provider performing specimen collection or running the test. IFUs should be carefully followed with attention to hand hygiene, glove use, and environmental cleanliness.

Measures should be taken to reduce the risk of result reporting errors by choosing an appropriate patient ID to key enter into the POC instrument and label the collected specimen. The best practice is to use the patient's MRN number or a combination of the full name and date of birth to ensure the results are matched correctly to individual being tested.

Interpreting Results

Clinical presentation and pretest probability should be carefully considered in evaluating results from POC testing platforms. When pre-test probability is low (e.g., absence of compatible symptoms, limited COVID circulation in the community, patient was not exposed to COVID, no outbreaks in the community), there is an increased likelihood of false positives and an increased likelihood of true negatives. When the pre-test probability is high (e.g., presence of compatible symptoms, COVID circulation in the community is high, patient exposed to COVID, outbreaks in the community), there is an increase likelihood of true positives and an increased likelihood of false negatives. These factors must be considered along with proper laboratory techniques when interpreting the results of antigen tests.

Per the FDA EUA, positive results must be used in conjunction with clinical presentation and patient history. Negative results should be treated as presumptive and do not rule out COVID-19. If there is still concern that a person has COVID-19 after a negative POC test, that person should be tested again using a different authorized molecular test. For testing in long-term care facilities, see guidance provided in PA-HAN-526.

CLIA Certification

Facilities utilizing POC tests for COVID-19 must have a Pennsylvania laboratory permit and a Clinical Laboratory Improvement Amendments (CLIA) Certificate of Waiver. If you have questions about laboratory permits or CLIA certification, please notify RA-DHPACLIA@pa.gov to assure laboratory compliance.

Training

Facilities must carefully review the Instructions for Use (IFU) and must train staff on the collection of specimens and performance of the test according to the IFU. Use online training videos provided by the company or the package insert instructions. Document staff training and competency.

The Centers for Disease Control and Prevention (CDC) Booklet Ready, Set, Test is a good resource for ensuring that staff has the basic training necessary to safely and accurately perform POC laboratory testing. An online training which conveys information in this booklet is also available and offers educational credits for a number of different professions. Familiarity with good laboratory techniques will improve the accuracy of results from these POC tests.

Reporting Results to PA-NEDSS

All positive, negative and inconclusive/indeterminate results must be reported within 24 hours to Pennsylvania's electronic surveillance system, PA-NEDSS. Do not report "invalid" results; repeat testing as per the  IFU. To request a PA-NEDSS account, complete the PA-NEDSS Prime Contact Information Form and send it to PA-NEDSS@pa.gov. The facility will then receive registration instructions and training materials. 

A "prime contact" for the facility will need to be named; the prime contact can then add people who are designated to report on behalf of the facility. Training information will be sent with the registration information. The attached Disease Reporter Guide also provides instructions. The following fields are required:

• Patient name
• Patient date of birth
• Patient address (use the address of the facility for residents; employees must have their residential address reported)
• Patient race and ethnicity
• Patient phone number (can use facility phone number for residents)
• Patient gender
• Test name
  • For molecular detection tests, choose "2019 novel coronavirus nucleic acid detection (rRT-PCR, probe)"
  • For antigen detection tests, choose "2019 novel coronavirus ANTIGEN detection"
• Test information
  • Specimen collection date
  • Test completed date (for point-of-care testing these dates are likely to be the same)
    

Key training resources for PA-NEDSS include the New User Guide, Disease Reporter Guide, and Technical Bulletin which provides basic technical information for PA-NEDSS.

Additional resources:

• COVID PA-NEDSS Reporting (9/18/2020)
• NEDSS Data Entry FAQ (9/18/2020)

Additional Requirements

Follow manufacturer's instructions for performance of the test.

Resources

CMS guidance for how to receive a CLIA Certificate of Waiver
https://www.cms.gov/Regulations-and-Guidance/Legislation/CLIA/Downloads/HowObtainCertificateofWaiver.pdf

Table of Point-of-Care Tests for COVID-19

*These resources were obtained from the Food & Drug Administration (FDA) website and are subject to change. This table contains information for select devices. Additional devices are listed on the FDA website. If the links provided no longer function, or you need additional information, we advise going to the FDA COVID-19 Emergency Use Authorization (EUA)website, under the section for COVID Invitro Diagnostic Products. From there, type the name of the instrument into the search box or browse the list provided.

Footnotes

1. Individuals suspected of COVID-19 infection or exposure can be symptomatic, pre-symptomatic, or asymptomatic. Diagnostic tests authorized for use on individuals suspected having of COVID-19 by their healthcare provider may be performed on specimens from certain asymptomatic individuals (e.g., those who have likely been exposed to an infected individual).
2. Follow the collection procedure outlined in the instructions for use (IFU).
3. The Department of Health has sufficient evidence to conclude that detection of SARS-CoV, the virus that causes SARS, will not be a significant contributor to the detection of antigen using this test based on the current absence of SARS-CoV in the Commonwealth at this time.

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