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COVID-19 Client Alerts:The CDC issued new guidance yesterday on the standards for discontinuing home isolation of people with COVID-19. Employers should follow these guidelines for determining when employees can return to work. Prior to the update, employers were advised they could return employees with COVID-19 to the workplace under either a test-based strategy (where the return is contingent upon COVID-19 testing) or a symptom-based strategy (where the return is contingent upon a certain passage of time). Under the new guidance, a test-based strategy is no longer recommended, except in limited circumstances. Instead, employers should use the symptom-based strategy. Changes to the symptom-based strategy have been made based on new information about the virus. The new criteria for returning employees to work under the symptom-based strategy are: 1. In general, people with COVID who have symptoms may return to work under the following conditions:
*For people with severe symptoms, 20 days may be required before they are no longer contagious. 2. People who tested positive with COVID who have no symptoms may return to work 10 days after their test, assuming they do not develop symptoms in the meantime. Per the current EEOC guidance, employers may require sick employees to obtain a return to work release from a health care provider. Copyright © 2020, Murphy Austin Adams Schoenfeld LLP. All rights reserved. Please be assured that we make every effort to make certain that the information contained in this alert is current at the time this email was delivered. Because laws and legislation are constantly changing, please contact us if you are unsure whether this material is still current. Nothing contained herein should be construed as legal advice or a legal opinion on any specific facts or circumstances. The contents are intended to be for general information purposes only. We assume no liability in connection with the use of the information contained in this article. Given the rapidly evolving nature of legal and governmental responses to the COVID-19 pandemic, unfolding events likely will supersede many of the issues discussed in these updates. We encourage you to contact our lawyers directly for the most current information and counsel regarding legal and governmental responses to the COVID-19 pandemic. Please contact us to answer any questions you may have. Murphy Austin's Labor and Employment Law Team Please contact one of our team members if we can be of assistance. ‹ Return to COVID-19 Client Alerts Overview of Testing for SARS-CoV-2, the virus that causes COVID-19Overview of Testing for SARS-CoV-2, the virus that causes COVID-19 Key Points
This overview describes current information on the types of tests used to detect SARS-CoV-2 infection and their intended uses. This information is intended for use by healthcare providers, public health professionals, and those organizing and implementing testing in non-healthcare settings, such as schools, workplaces, and congregate housing. Information for the general public on SARS-CoV-2 testing is also available. Considerations When TestingPeople undergoing testing should receive clear information on
Individuals tested are required to receive patient fact sheets as part of the test’s Emergency Use Authorization (EUA). Testing for SARS-CoV-2 InfectionMany types of tests are used to detect SARS-CoV-2,1 and their performance characteristics vary.
Test TypesViral tests, including Nucleic Acid Amplification Tests (NAATs, such as Reverse Transcription – Polymerase Chain Reaction), antigen tests and other tests (such as breath tests) are used as diagnostic tests to detect current infection with SARS-CoV-2 and to inform an individual’s medical care. Viral tests can also be used as screening tests to reduce the transmission of SARS-CoV-2 by identifying infected persons who need to isolate from others. Viral Tests include:
Positive viral test results allow for identification and isolation of infected persons. Negative viral test results suggest no current evidence of infection. These results represent a snapshot of the time around specimen collection and could change if the same test was performed again in one or more days. Antibody (or serology) tests are used to detect previous infection with SARS-CoV-2 and can aid in the diagnosis of multisystem inflammatory syndrome in children (MIS-C) and in adults (MIS-A)2. Antibody testing does not diagnose current infection. Antibody testing is being used for public health surveillance and epidemiologic purposes. Antibody tests detect specific antibodies that target different parts (nucleocapsid or spike protein) of the virus. This should be considered when choosing whether to test for antibodies originating from past infection versus those from vaccination. For more information about COVID-19 vaccines and antibody test results, refer to Interim Clinical Considerations for Use of mRNA COVID-19 Vaccines Currently Authorized in the United States. See FDA’s list of In Vitro Diagnostics Emergency Use Authorizations for more information about the performance and interpretation of specific authorized tests. Overview of Testing ScenariosDiagnostic testing is intended to identify current infection in individuals and is performed when a person has signs or symptoms consistent with COVID-19, or is asymptomatic, but has recent known or suspected exposure to someone with suspected or confirmed SARS-CoV-2 infection. Screening testing is intended to identify people with COVID-19 who are asymptomatic or do not have any known, suspected, or reported exposure to SARS-CoV-2. Screening helps to identify unknown cases so that steps can be taken to prevent further transmission. Public health surveillance testing is intended to monitor population-level burden of disease, or to characterize the incidence and prevalence of disease. Surveillance testing is primarily used to gain information at a population level, rather than an individual level, and generally involves testing of de-identified specimens. Surveillance testing results are not reported back to the individual. As such, surveillance testing cannot be used for an individual’s healthcare decision-making or individual public health actions, such as isolation. An example of surveillance testing is wastewater surveillance. NOTE: For guidance on using tests to determine which mitigations are recommended as someone recovers from COVID-19, see the Isolation and Precautions for People with COVID-19. Choosing a TestWhen choosing which test to use, it is important to understand the purpose of the testing (diagnostic or screening), test performance in context of COVID-19 incidence, need for rapid results, and other considerations (See Table 1). Use of a laboratory-based NAAT in areas where COVID-19 Community Level and testing demand is high may result in diagnostic delays due to processing time and time to return results. Positive and negative predictive values of NAAT and antigen tests vary depending upon the pretest probability. Pretest probability considers both the COVID-19 Community Level as well as the clinical context of the individual being tested. Additional information is available on sensitivity, specificity, positive and negative predictive values for antigen tests and antibody tests, and the relationship between pretest probability and the likelihood of positive and negative predictive values. Table 1 summarizes some characteristics of NAATs and antigen tests to consider for a testing program. FDA has provided additional information for healthcare providers who are using diagnostic tests in screening asymptomatic individuals, and the Centers for Medicare & Medicaid Services has exercised enforcement discretion under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) to enable the use of antigen tests that are not currently authorized for use in asymptomatic individuals for the duration of the COVID-19 public health emergency. Laboratories that perform screening or diagnostic testing for SARS-CoV-2 must have a CLIA certificate and meet regulatory requirements. Tests that have received an EUA from FDA for point-of-care (POC) use can be performed with a CLIA certificate of waiver. Vaccination and SARS-CoV-2 TestingIf a person has received one or more COVID-19 vaccinations, it does not affect the results of their SARS-CoV-2 diagnostic or screening tests (nucleic acid amplification tests [NAAT], antigen or other diagnostic tests). Because mRNA COVID-19 vaccines use the SARS-CoV-2 spike protein to generate an immune response, a positive serologic (antibody) test for spike protein IgM/IgG could indicate either previous infection or vaccination. Antibody testing is not currently recommended to assess a person’s protection against infection or severe COVID-19 following COVID-19 vaccination or prior infection, or to assess the need for vaccination in an unvaccinated person. To evaluate for evidence of previous infection in a vaccinated individual, an antibody test specifically evaluating IgM/IgG to the nucleocapsid protein should be used (e.g., for public health surveillance or the diagnosis of Multisystem Inflammatory Syndrome in Children (MIS-C) or Multisystem Inflammatory Syndrome in Adults (MIS-A)). Table 1. NAAT and Antigen Test Differences to Consider When Planning for Diagnostic or Screening Use NAATsNAATsAntigen Tests*Antigen Tests*Diagnose current infection Diagnose current infection Diagnose current infection Diagnose current infection Viral Ribonucleic Acid (RNA) Viral Ribonucleic Acid (RNA) Nasal, Nasopharyngeal, Oropharyngeal, Sputum, Saliva Nasal, Nasopharyngeal, Oropharyngeal, Sputum, Saliva Varies by test, but generally high for laboratory-based tests and moderate-to-high for POC tests Varies by test, but generally high for laboratory-based tests and moderate-to-high for POC tests Varies depending on the course of infection† Varies depending on the course of infection† Authorized for Use at the Point-of-Care Authorized for Use at the Point-of-Care Most 1-3 days. Some could be rapid in 15 minutes Most 1-3 days. Some could be rapid in 15 minutes Ranges from 15 minutes to 30 minutes Ranges from 15 minutes to 30 minutes Moderate (~$75-$100/test) Moderate (~$75-$100/test) Most sensitive test method available Short turnaround time for NAAT POC tests, but few available Usually does not need to be repeated to confirm results Most sensitive test method available Short turnaround time for NAAT POC tests, but few available Usually does not need to be repeated to confirm results Short turnaround time (approximately 15 minutes) ◊ When performed at or near POC, allows for rapid identification of infected people, thus preventing further virus transmission. Short turnaround time (approximately 15 minutes) ◊ When performed at or near POC, allows for rapid identification of infected people, thus preventing further virus transmission. Longer turnaround time for lab-based tests (1–3 days) Higher cost per test After an infection has ended, and the risk of transmission has passed, people may have detectable RNA and test positive for up to 90 days Longer turnaround time for lab-based tests (1–3 days) Higher cost per test After an infection has ended, and the risk of transmission has passed, people may have detectable RNA and test positive for up to 90 days Negative tests should be repeated per FDA guidance May need confirmatory testing Less sensitive (more false negative results) compared to NAATs, especially among asymptomatic people and with some variants Negative tests should be repeated per FDA guidance May need confirmatory testing Less sensitive (more false negative results) compared to NAATs, especially among asymptomatic people and with some variants * As noted in the labeling for authorized over-the- counter antigen tests: Negative results should be treated as presumptive (meaning that they are preliminary results). Negative results do not rule out SARS-CoV-2 infection and should not be used as the sole basis for treatment or patient management decisions, including infection control decisions. Please see FDA guidance on the use of at-home COVID-19 antigen tests. † The decreased sensitivity of antigen tests might be offset if the POC antigen tests are repeated more frequently. Health Equity in SARS-CoV-2 TestingSocial determinants of health may influence access to testing. For example, travel time may limit access to, and use of, testing services for those who have limited access to transportation and who live in areas with fewer public transit services and schedules. Racial and ethnic disparities in test site distribution have been found.3 Other factors that may affect both access to, and use of, testing services include:
Delays in testing may also delay seeking care when sick as well as delays in self-isolation that could reduce the spread of the virus to others. CDC’s COVID-19 Response Health Equity Strategy outlines a plan to reduce the disproportionate burden of COVID-19 among racial and ethnic minority populations and other population groups (e.g., essential and frontline workers, people living in rural or frontier areas) who have experienced a disproportionate burden of COVID-19. One component to move towards greater health equity is ensuring availability of resources, including access to testing for populations who have experienced longstanding, systemic health and social inequities. All population groups, including racial and ethnic minority groups, should have equal access to affordable, quality and timely SARS-CoV-2 testing—with fast turnaround time for results—for diagnosis and screening. Efforts should be made to address barriers that might overtly or inadvertently create inequalities in testing. In addition, completeness of race and ethnicity data is an important factor in understanding the impact the virus has on racial and ethnic minority populations. The U.S. Department of Health and Human Services has required laboratories and testing facilities to report race and ethnicity data to health departments, in addition to other data elements, for individuals tested for SARS-CoV-2 or diagnosed with COVID-19. Healthcare providers and public health professionals need to ask and record race and ethnicity for anyone receiving a reportable test result and ensure these data are reported with the person’s test results in order to facilitate understanding the impact of COVID-19 on racial and ethnic minority populations. Some strategies to achieve health equity in testing access and availability include:
Considerations for testing in different scenariosDiagnostic testingTesting persons with signs or symptoms consistent with COVID-19Positive test results using a viral test (NAAT, antigen or other tests) in persons with signs or symptoms consistent with COVID-19 indicate that the person has COVID-19, independent of vaccination status of the person. A negative antigen test in persons with signs or symptoms of COVID-19 should be confirmed by NAAT, a more sensitive test. For more information, see the Antigen Test Algorithm. All persons (independent of vaccination status) with positive results should isolate at home or, if in a healthcare setting, be placed on appropriate precautions. Some people should receive treatment. Most people with COVID-19 have mild illness and can recover at home without medical care. For more information, see CDC’s COVID-19 isolation guidance. Testing asymptomatic persons who have had recent known or suspected exposure to SARS-CoV-2Viral testing is recommended for individuals who have been exposed to persons with COVID-19. People who have had an exposure with someone known or suspected of having COVID-19 should be tested at least 5 days after the exposure. If symptoms develop before 5 days, they should get tested immediately. In instances of higher pretest probability, such as high incidence of infection in the community, or a person with household or continuous contact with a person with COVID-19, clinical judgement should determine if a positive antigen result for an asymptomatic person should be followed by a laboratory-based confirmatory NAAT. Results from NAATs are considered the definitive result when there is a discrepancy between the antigen and NAAT test. For more information, see the antigen test algorithm. Persons with positive results should follow CDC’s COVID-19 isolation guidance. Testing persons who have recently tested positive, and recovered from COVID-19If someone has had exposure to someone with COVID-19 and is asymptomatic, but has had COVID-19 within the past 30 days,* testing to identify a new infection is generally not recommended. If someone has become newly symptomatic after having had COVID-19 within the past 30 days,* antigen tests should be used to identify a new infection. If they test negative, the antigen test should be repeated per FDA guidance. If someone had exposure to another person with COVID-19, but the exposed individual has had COVID-19 within the past 30-90 days,* consider using antigen tests (rather than an NAAT, such as a PCR test) to identify a new infection. They should not test until at least 5 days after their exposure. Whether they are symptomatic or asymptomatic, if they test negative with an antigen test, they should repeat the antigen test as recommended by FDA guidance. *The clock starts from the day of your first positive test result or your original onset of symptoms, whichever came first. Some adults with severe illness may produce replication-competent virus beyond 10 days that may warrant extending duration of isolation and precautions. A test-based strategy for ending isolation may be considered in consultation with infectious disease experts for persons with severe illness or who are severely immunocompromised. For more information, including on retesting persons previously infected with SARS-CoV-2, visit Ending Isolation and Precautions for People with COVID-19: Interim Guidance. Screening TestingTesting asymptomatic persons without recent known or suspected exposure to SARS-CoV-2 for early identification, isolation, and disease prevention Screening testing allows early identification and isolation of persons who are asymptomatic or pre-symptomatic and who might be unknowingly transmitting virus. Screening testing may be most valuable in certain settings where early identification is essential to reducing transmission and mitigating risk for severe disease among populations at high risk. CDC’s COVID-19 Community Levels recommendations include implementing screening testing in high-risk settings at the medium and high levels. Examples of screening testing include:
How to conduct screening testingWhen screening testing is used, it should be applied to participants regardless of vaccination status. People without symptoms and without known exposure to COVID-19 do not need to take any special actions while awaiting screening test results. If a person tests positive on a screening test and is referred for a confirmatory test, they should isolate until they receive the results of their confirmatory test. Settings to prioritize for screening testingSettings that should be prioritized for screening testing include facilities and situations where transmission risk is high and the population served is at high risk of severe outcomes from COVID-19 or there is limited access to healthcare, including:
Serial screening testing is less effective at reducing COVID-19’s impacts in settings where disease rates are lower, risk of spread is lower, and risk of severe illness is lower. Because of this, CDC does not recommend serial screening testing in most lower risk settings. Setting-specific Testing Guidance
Previous UpdatesUpdates as of May 27, 2022
As of January 21, 2022
As of October 22, 2021
As of August 2, 2021
As of July 1, 2021
As of June 14, 2021
As of September 18, 2020
As of August 24, 2020
As of July 17, 2020
As of July 2, 2020
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