Reopening for Business: COVID-19 Medical Tests for Employees
As organizations prepare to reopen for business, many are considering medical tests as a screening tool. It is important to understand the facts regarding the benefits and limitations of these tests when including them in a strategy for returning employees to the workplace. Without a proper understanding of the criteria for interpreting the results, a testing program may be wrongly implemented and provide a false sense of security.
Diagnostic Test – Ribonucleic Acid (RNA)/Polymerase Chain Reaction (PCR)
There are different types of tests available related to COVID-19 disease. There are diagnostic tests that determine whether the SARS-CoV-2 virus is present by detection of RNA (the virus genetic material). To collect a sample, a swab must be inserted deep into the nasal cavity. Nasopharyngeal material is then extracted, and a molecular test called polymerase chain reaction (PCR) is conducted in a laboratory. The test determines if a person is currently infected with the virus that causes COVID-19.
Disadvantages to this type of sample collection and testing include:
- False negative results reported due to improperly collected nasopharyngeal material.
- Shortages of swabs and personal protective equipment (PPE) for healthcare workers who collect the samples.
- Employee discomfort with collection of the sample.
Recently however, researchers at Yale University found that a saliva sample can be used instead of nasopharyngeal material and also provide greater detection sensitivity. They concluded that saliva based tests are a preferable indicator for infection with less variability in results and could enable at-home, self-administered sample collection for SARS-CoV-2 testing. Validation of the results is currently underway. On April 13, 2020, the Food and Drug Administration (FDA) approved a saliva based test developed by RUCDR Infinite Biologics and a commercial partner under an Emergency Use Authorization (EUA). The tests must be ordered by a physician and conducted in a healthcare setting under the supervision of a qualified professional. To meet this requirement, the company plans to mail the sample collection kit to the user and conduct a video telehealth visit to ensure proper sample collection. This would eliminate the risk of person-to-person exposure and minimize costs associated with sample collection by a healthcare professional.
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Regardless of the method used, an individual’s infection status can change if they become exposed to the virus after the test is conducted. Therefore, weekly testing would be recommended to effectively screen employees for the workplace.
One barrier to implementation of this as a routine screening tool is the limited availability of the RNA/PCR tests because rules for allocation vary from state to state. In some locations, testing is only available for those who are ill with symptoms of COVID-19, people with a physician’s order or workers who are first responders (police, firefighters, EMS), healthcare workers or others in essential services sectors such as public facing workers. Several cities across the U.S. are starting to roll-out expanded testing programs for their citizens. Some have no restrictions on who may receive the tests while others still require completion of a pre-screening questionnaire and appointments prior to administering the tests. Restrictions on who is eligible for testing should continue to be relaxed as the availability of test kits become more readily available. Companies may want to contract with specific laboratories to ensure consistency with interpretation of results if they are planning to use this as an ongoing screening tool for employees.
The other type of test is called serology or antibody testing to SARS-CoV-2. This is done with blood samples collected from a small finger prick to see if a person’s immune system demonstrates a combative response to the virus. Typically, the body’s immune system develops antibodies when they are exposed to a pathogen (such as a virus) to destroy or neutralize it. The immune system will then recognize this pathogen if it is encountered in the future and mobilize a response and generally provide some level of immunity against the virus. A positive antibody test means that an individual was exposed to SARS-CoV-2 at some point in the past and their immune system was able to launch an antibody-forming immune response. Employers would like to use a positive antibody test as a means to “clear” employees to come back to the workplace under the premise that they are immune to infection and cannot infect others. At this time, however, it is unknown whether a positive antibody test can affirm that a person has immunity and will be protected from infection or reinfection with COVID-19 disease. In addition, we do not yet know how long antibodies to SARS-CoV-2 stay in the body. So, if a person is immune, it is unknown how long that immunity might last. Therefore, the antibody test is not useful as a screening tool to determine potentially infective people, or those that have long-term immunity, based on the information currently available.
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The majority of the antibody tests currently on the market for COVID -19 have not undergone full FDA review and are inconsistent in reliability. The CDC is currently evaluating the performance of these commercially available tests and it is anticipated that the CDC will soon provide guidelines for how the results should be interpreted and used. FDA EUA approved tests can be found on the FDA website.
Organizations must understand the various types of testing and their advantages and disadvantages before incorporating testing into their plan for returning staff to the workplace. If not carefully selected and implemented, it could result in misinterpretation of test results, leading to misinformed decisions for managing the risks of disease transmission in the workplace.
EH&E offers a multidisciplinary team of experts, including medical professionals and occupational health specialists, who understand the science and health implications surrounding the coronavirus. If you need guidance on how to safely re-open your workplace and continue operations, contact us today to speak with an expert.
Development and validation of testing methods for SARS-CoV-2 are ongoing and over the course of time more information and data will become available. This post reflects information available as of the publication date and will be updated as new information becomes available.
Centers for Disease Control and Prevention (accessed 5/5/20): https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/testing.html
World Health Organization (accessed 5/5/20): https://www.who.int/news-room/commentaries/detail/immunity-passports-in-the-context-of-covid-19
Wyllie AL et al. Saliva is more sensitive for SARS-CoV-2 detection in COVID-19 patients than nasopharyngeal swabs. Preprinted – medRxiv, April 16, 2020.
Rutgers University, RUCDR Infinite Biologics (accessed 5/5/20): https://www.rutgers.edu/news/new-rutgers-saliva-test-coronavirus-gets-fda-approval
Vault Health (accessed 5/5/20): https://www.vaulthealth.com/covid
Quest Diagnostics (accessed 5/5/20): https://questdirect.questdiagnostics.com/products/covid-19-immune-response/b580e541-78a5-48a6-b17b-7bad949dcb57?utm_source=google&utm_medium=cpc&utm_campaign=71700000066217190&utm_content=58700005845625577&utm_term=p53388864531&gclid=EAIaIQobChMIl6Gi0K6b6QIVBsRkCh2_0AihEAAYASAAEgL-RvD_BwE&gclsrc=aw.ds
Wajnberg et al. Humoral immune response and prolonged PCR positivity in a cohort of 1343 2 SARS-CoV 2 patients in the New York City region. Preprinted – medRxiv, April 30, 2020.