Is it possible to provide an evidence-based diagnostic framework for the diagnosis of COVID-19 as a work-related illness? Some states (such as CA) have implemented presumption laws for COVID illnesses. It would be beneficial to have a reference which looks at PCR and antibody testing as methods to validate COVID diagnosis in someone who was symptomatic but unable to verify with PCR.

Determining whether a worker has COVID-19 and whether it can be considered a work-related illness requires an analysis of both the clinical diagnosis and possible work attribution.

CDC has developed a surveillance case definition for a probable case or death of COVID-19:
  1. Meeting clinical criteria AND epidemiologic evidence with no confirmatory laboratory testing performed for COVID-19; or 
  2. Meeting presumptive laboratory evidence AND either clinical criteria OR epidemiologic evidence; or 
  3. Meeting vital records criteria with no confirmatory laboratory testing performed for COVID-19.1,2
 A surveillance case definition is intended to cast a wide net in defining a disease consistently but is not intended to be used for making a clinical diagnosis.3 However, it is a useful starting place, which can be supplemented by additional clinical, epidemiological, laboratory, and radiologic data in making a clinical diagnosis when all elements of the surveillance case definition are not met. In many cases, the diagnosis will be straightforward, with typical symptoms and a positive RT-PCR test result. However, sometimes the clinical diagnosis can be more challenging as the illness can have a widely varied presentation and course. And RT-PCR can have a high percentage of false negative results.4 In a pooled analysis, the probability of a false negative RT-PCR was 38% on the day of symptom onset, decreasing to 20% three days later.4 A negative RT-PCR result should therefore not exclude a diagnosis of COVID-19 if the diagnosis is strongly suspected on clinical grounds.

In the case of suspected COVID-19 with a negative RT-PCR result, the use of a reliable and validated antibody test could potentially be helpful. The challenge is that more than 100 antibody tests are currently marketed and many tests are not reliable.5 When using an antibody test to confirm the diagnosis, it is critical to know which test was performed and the specificity and sensitivity of the test, as many will have high rates of false positives and/or false negatives. It is also important to look at when the test was performed in the course of illness as positive results are not reliably seen until 2 weeks into the illness.5 A clinical diagnosis can still be made based on the judgement of the clinician even in the absence of laboratory confirmation.

Once a clinical diagnosis has been made, a determination of work attribution is important for determining OSHA Recordability and how the illness will be treated under Workers Compensation.

On May 19, OSHA provided revised guidance on work-relatedness determinations (removing the previous differing approaches for healthcare and non-healthcare settings). OSHA now only requires the recording of “confirmed cases”, which require at least one respiratory specimen that tested positive for SARS-CoV-2.6 Under OSHA's revised recordkeeping requirements, COVID-19 is a recordable illness if:
  • The case is a confirmed case of COVID-19, 
  • The case is work-related if an event or exposure in the work environment either caused or contributed to the resulting condition, and
  • The case results in death, days away from work, restricted work or transfer to another job, medical treatment beyond first aid, loss of consciousness, or the illness is diagnosed by a physician or other licensed health care professional. 6

Whether an illness is compensable under Workers Comp is determined by the specific laws of the state where the employer is located. For example, on May 6, Governor Newsom of California issued an Executive Order which stated that: “Any COVID-19-related illness of an employee shall be presumed to arise out of and in the course of the employment for purposes of awarding workers’ compensation benefits” if “the employee tested positive for or was diagnosed with COVID- 19 within 14 days after a day that the employee performed labor or services”.7 Under this order, this determination of work-relatedness creates a rebuttable presumption, meaning that an employer can challenge the determination if there is evidence that the illness was acquired elsewhere.The Illinois Workers Comp Commission passed a similar requirement, presuming that “workers contracted COVID-19 on the job if they work at businesses deemed essential by the state’s stay-at-home order, such health care, banks and grocery stores.”8 However, this was challenged and a judge halted enforcement of the rule, so that, like many states, Illinois still “requires employees to prove that their workplace was the cause of their illness.”8 Minnesota has enacted a statutory presumption of COVID-19 as an occupational disease for police, emergency responders, correctional workers, and certain healthcare and childcare workers.9 Many states also exclude “ordinary diseases of life”. Whether COVID-19 is compensable will therefore depend on the laws of the state and the specific circumstances of each case. 
 
 

Citations

  1. CDC. FAQ: COVID-19 Data and Surveillance. April 17, 2020. https://www.cdc.gov/coronavirus/2019-ncov/covid-data/faq-surveillance.html
  2. CDC. Coronavirus Disease 2019 (COVID-19) 2020 Interim Case Definition, Approved April 5, 2020. https://wwwn.cdc.gov/nndss/conditions/coronavirus-disease-2019-covid-19/case-definition/2020/ 
  3. CDC. Surveillance Case Definitions. https://wwwn.cdc.gov/nndss/case-definitions.html 
  4. Kucirka et al. Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction–Based SARS-CoV-2 Tests by Time Since Exposure. Ann Int Med, May 13, 2020. https://doi.org/10.7326/M20-1495  
  5. Whitman et al. Test performance evaluation of SARS-CoV-2 serological assays. April 29, 2020. https://doi.org/10.1101/2020.04.25.20074856 
  6. US Department of Labor. Revised Enforcement Guidance for Recording Cases of Coronavirus Disease 2019 (COVID-19). May 19, 2020. April 10, 2020. https://www.osha.gov/memos/2020-05-19/revised-enforcement-guidance-recording-cases-coronavirus-disease-2019-covid-19
  7. Newsom G. Executive Order N-62-20. May 6, 2020. https://www.gov.ca.gov/wp-content/uploads/2020/05/5.6.20-EO-N-62-20-text.pdf 
  8. Elejalde-Ruiz A. If you get sick with COVID-19, is your employer liable? As businesses prepare to reopen, worker safety is a priority. Chicago Tribune, May 4, 2020.  https://www.chicagotribune.com/coronavirus/ct-coronavirus-employer-liability-workplace-exposure-20200501-dye6husnszchpnpaadiensn2ja-story.html 
  9. Minnesota Department Labor and Industry. Workers’ compensation COVID-19 presumption.  April 8, 2020. https://www.dli.mn.gov/sites/default/files/pdf/COVID-19_work_comp_presumption.pdf

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Disclaimer:
The Forum does not necessarily represent an official ACOEM position. The Forum is intended for health professionals and is not intended to provide medical or legal advice, including illness prevention, diagnosis or treatment, or regulatory compliance. Such advice should be obtained directly from a physician and/or attorney. Questions are answered with the best available data or recommendations at the time.