HCP meets CDC symptom strategy guides but continues to test positive. What are the safe guidelines for RTW?

This question asks for safe RTW guidelines for Health Care Personnel (HCP) who could return to work based on CDC symptoms-based strategies for HCP1 but continue to test positive for COVID-19. 

The CDC recommends several possible strategies for HCP to return to work after COVID-19. If the HCP had symptoms the employer may use a test-based strategy or a symptom-based strategy. The symptom-based strategy requires work exclusion for 10 days from symptom onset, and for at least 3 days from clinical recovery (defined as absence of fever without use of fever-reducing medicines, and improvement in symptoms.) The test-based RTW criteria include clinical recovery (as above but without the 3 day requirement) plus 2 consecutive negative molecular tests (e.g. RT-PCR) collected at least 24 hours apart. 

For asymptomatic HCP who have tested positive for COVID-19, employers may use a test-based strategy requiring 2 consecutive negative molecular tests at least 24 hours apart, or a time-based strategy requiring work exclusion for 10 days from the positive test. Employers can adopt either strategy as recommended by CDC.

It is important that employees are not excluded from work, or required to return to work, for subjective or inconsistent reasons. 

Viral burden measured in upper respiratory specimens declines after onset of illness.2 In presymptomatic and asymptomatic patients, detection of virus can be as early as six days prior to the development of typical symptoms.3 

Viral shedding can occur for up to 6 weeks or longer.2 The length of illness and duration of post-recovery shedding of detectable viral RNA in the upper respiratory tract is not clearly described, but persistently positive nasopharyngeal, throat, and salivary specimens are not uncommon 3 weeks after recovery.10,11,12

Modest viral loads in the respiratory tract occur early in the illness, with viral loads highest approximately 10 days after symptom onset among those with mild illness and longer among those with severe illness.4,7 Detection of viral RNA does not necessarily indicate the presence of infectious virus. In one study of 12 patients, replication-competent virus was not successfully cultured from PCR-positive specimens collected more than 9 days after onset of illness, but not all samples beyond that time were tested.2,6 More research is needed to determine the length of the infectious period as we lack evidence to rule out the possibility of persistent or intermittent shedding of infectious virus, reactivation, or even reinfection. As the likelihood of isolating a replication-competent virus decreases, anti-SARS-CoV-2 IgM and IgG can be detected in an increasing number of persons recovering from infection.3   

Guidance to safely return to work:

CDC initially preferred the test-based strategy for HCP return to work, however in an update April 30, 2020 they adopted a neutral stance between the test-based and symptom-based strategies.1 OEM physicians should be aware of any state or local requirements for HCP return to work.1 OEM physicians can help employers understand the science underlying different RTW recommendations and requirements and assist them in defining a RTW strategy that aligns with their institutional needs. 

For employers using a test-based strategy, it may be helpful to plan for outliers with detectable viral RNA for an unusually long duration.  One strategy might be to offer antibody testing.  Since serology does not, at this time, confirm or refute the presence of active infection, serology testing can not be required as a condition of RTW,13 this could be presented as an option for the employee to help determine where they lie in the course of the disease.  It is important to consider the sensitivity and specificity of each testing method 8,9,14,15 the rate of false positives and false negatives, and other known caveats of serologic testing.16

Symptomatic HCP with suspected or confirmed COVID-19 could return to work after at least 10 days have passed since symptoms first appeared or at least 3 days (72 hours) have passed since resolution of fever without fever reducing medications and improvement in respiratory symptoms.1 HCP  with laboratory confirmed COVID-19 who do not have symptoms could return to work based on a time-based strategy after 10 days have passed since first positive COVID-19 diagnostic test assuming they have not developed symptoms since their positive test.1   

On return to work, HCP should use a facemask until all symptoms are resolved and for at least 14 days after illness onset, and then follow the facility's policy regarding universal masking for source control. In addition, they should self-monitor for symptoms, and seek re-evaluation from occupational health if respiratory symptoms recur or worsen.


  1. Criteria for Return to Work for Healthcare Personnel with Suspected or Confirmed COVID-19 (Interim Guidance) https://www.cdc.gov/coronavirus/2019-ncov/hcp/return-to-work.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Fhealthcare-facilities%2Fhcp-return-work.html
  2. Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19
  1. Arons, M. M., Hatfield, K. M., Reddy, S. C., Kimball, A., James, A., Jacobs, J. R., ... & Tanwar, S. (2020). Presymptomatic SARS-CoV-2 infections and transmission in a skilled nursing facility. New England Journal of Medicine.
  2. Zou, L., Ruan, F., Huang, M., Liang, L., Huang, H., Hong, Z., ... & Guo, Q. (2020). SARS-CoV-2 viral load in upper respiratory specimens of infected patients. New England Journal of Medicine. 2020 382(12), 1177-1179.
  3. Wölfel, R., Corman, V. M., Guggemos, W., Seilmaier, M., Zange, S., Müller, M. A., ... & Hoelscher, M. (2020). Virological assessment of hospitalized patients with COVID-2019. Nature, 1-5.
  4. Midgley CM, Kujawski SA, Wong KK, Collins, JP, Epstein ., Killerby ME et al. (2020). Clinical and Virologic Characteristics of the First 12 Patients with Coronavirus Disease 2019 (COVID-19) in the United States. Nature Medicine 2020 Apr 23. doi:10.1038/s41591-020-0877-5.
  5. Zheng, S., Fan, J., Yu, F., Feng, B., Lou, B., Zou, Q., ... & Chen, W. (2020). Viral load dynamics and disease severity in patients infected with SARS-CoV-2 in Zhejiang province, China, January-March 2020: retrospective cohort study. bmj, 369.
  6. Serology-based tests for COVID-19 https://www.centerforhealthsecurity.org/resources/COVID-19/serology/Serology-based-tests-for-COVID-19.htmlwebsite accessed on May 16, 2020
  7. Serology assays to manage COVID-19 F. Krammer, V. Simon, Science, 10.1126/science.abc1227 (2020).
  8. Zhou, F., Yu, T., Du, R., Fan, G., Liu, Y., Liu, Z., Xiang, J., Wang, Y., Song, B., Gu, X. and Guan, L., 2020. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. The lancet.
  9. Xiao AT, Tong YX, Zhang S. Profile of RT-PCR for SARS-CoV-2: a preliminary study from 56 COVID-19 patients. Clinical Infectious Diseases. 2020 Apr 19
  10. Xu K, Chen Y, Yuan J, Yi P, Ding C, Wu W, Li Y, Ni Q, Zou R, Li X, Xu M. Factors associated with prolonged viral RNA shedding in patients with COVID-19. Clinical Infectious Diseases. 2020 Apr 9.
  11. https://www.google.com/url?q=https://www.eeoc.gov/wysk/what-you-should-know-about-covid-19-and-ada-rehabilitation-act-and-other-eeo-laws&sa=D&ust=1589811163316000&usg=AFQjCNGeaNWIMtBbWc2FjKDbI5ewNwyglg
  12. Serology-based tests for COVID-19, https://www.centerforhealthsecurity.org/resources/COVID-19/serology/Serology-based-tests-for-COVID-19.html Website accessed on May 16, 2020.
  13. Serology assays to manage COVID-19. F. Krammer, V. Simon, Science. 10.1126/science.abc1227 (2020).
  14. Kirkcaldy, R. D., King, B. A., & Brooks, J. T. (2020). COVID-19 and Postinfection Immunity: Limited Evidence, Many Remaining Questions. JAMA.

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