Bureau of Communicable Diseases, May 8, 2020
Summary
- Wisconsin DHS and CDC now prioritize COVID-19 testing for asymptomatic people in a wider range of scenarios to support the public health response. This change reflects both growing testing capacity and the wider recognition of the importance of asymptomatic and presymptomatic transmission.
- DHS and CDC have revised recommendations about discontinuation of isolation for patients with COVID-19 in health care and non-health care settings. The recommended duration of isolation has been extended to be at least 10 days from the date symptoms first appeared.
Dear Colleagues,
Below please find new information about evolving guidance from CDC, which has been adopted by Wisconsin DHS for health care and public health partners in our state.
Testing of Asymptomatic People
There is growing evidence that persons with COVID-19 become infectious days prior to developing symptoms, and many develop only mild symptoms or no symptoms at all. In congregate living settings and workplaces where physical distancing is difficult to maintain, symptom-based screening alone is unlikely to detect all cases and testing a broader group of asymptomatic individuals may be necessary to control transmission. Laboratory capacity for COVID-19 capacity in Wisconsin is currently sufficient to recommend testing asymptomatic persons in a wider range of settings where detection of unrecognized cases serves an important public health purpose. On May 3, the CDC revised its guidance related to testing priorities for nucleic acid or antigen testing as follows:
High Priority
- Hospitalized patients with symptoms
- Healthcare facility workers, workers in congregate living settings, and first responders with symptoms
- Residents in long-term care facilities or other congregate living settings, including prisons and shelters, with symptoms
Priority
- Persons with symptoms of potential COVID-19 infection, including: fever, cough, shortness of breath, chills, muscle pain, new loss of taste or smell, vomiting or diarrhea, and/or sore throat.
- Persons withoutsymptoms who are prioritized by health departments or clinicians, for any reason, including but not limited to: public health monitoring, sentinel surveillance, or screening of other asymptomatic individuals according to state and local plans.
In Wisconsin, DHS recommends COVID-19 testing for asymptomatic individuals in the following situations:
- As part of public health investigations, such an outbreak involving multiple cases in a workplace.
- For individuals in congregate living situations such as nursing homes or assisted living facilities
- In health care settings, when needed to inform infection control interventions, such as before aerosol-generating procedures.
- In community settings, when testing of close contacts of confirmed cases would inform local public health interventions, such as contact tracing investigations, or decisions about location of quarantine* or isolation.
*In all the above situations, negative test results should not result in discontinuation of quarantine for people who have been close contacts to known cases, and who may still be in the incubation period. In other words, COVID-19 testing can be useful for detecting unrecognized cases (“ruling in”), but not excluding infection in people who were exposed (“ruling out”).
Revised Recommendations about Discontinuation of Isolation
To control community transmission of COVID-19 in Wisconsin, DHS continues to recommend that all individuals with suspected or confirmed COVID-19 remain in isolation until they are presumed to no longer be contagious. Based on updates to CDC’s interim guidance on Discontinuation of Isolation for Persons with COVID-19 Not in a Healthcare Setting and Return to Work Criteria for Healthcare Personnel, DHS is now recommending the following criteria be used to determine release from isolation of individuals with suspected or confirmed COVID-19. These criteria can be applied to all individuals with suspected or confirmed COVID-19, including health care workers and critical infrastructure workers.
Symptomatic individuals with suspected or confirmed COVID-19 should remain in isolation until:
- At least 10 days* have passed since symptoms first appeared, AND
- At least 3 days (72 hours) have passed since recovery. Recovery is defined as resolution of fever without the use of fever-reducing medications and improvement in respiratory symptoms (e.g., cough, shortness of breath)
Asymptomatic individuals with lab-confirmed COVID-19 should remain in isolation until:
- At least 10 days* have passed since the collection date of their first positive COVID-19 diagnostic test, assuming they have not subsequently developed symptoms. NOTE: patients who develop COVID-19 symptoms during this period should extend isolation precautions for at least 10 days from the date of symptom onset (see above).
Optional test-based strategy: DHS recommends the above strategies for discontinuation of isolation for most individuals; however CDC also provides guidance for a “test-based strategy” that may be considered in some circumstances, including immunocompromised persons. The decision to use a test-based strategy should take into consideration the availability of sufficient testing supplies and laboratory capacity, and is likely to result in longer time-periods for isolation.
*The recommended isolation period has been extended from a minimum of 7 days to a minimum of 10 days for both symptomatic and asymptomatic individuals with laboratory-confirmed COVID-19. This update is consistent with new CDC guidance and is based on new epidemiologic and laboratory evidence indicating a longer duration of viral shedding than previously believed.
DHS encourages all health care providers to communicate with patients at the time of initial diagnosis about public health recommendations regarding release from isolation and release, and to coordinate communicate with local public health officials about any concerns about individuals who may not be following these recommendations to local public health officials.
For more information, please visit the DHS COVID-19 webpages for those who have been diagnosed with COVID-19 and for health care providers.
For more information about hospitalized individuals, see CDC Interim Guidance for Discontinuation of Transmission-based Precautions and Disposition of Patients with COVID-19 in Healthcare Settings.
Sincerely,
Ryan Westergaard, MD, PhD, MPH
Chief Medical Officer and State Epidemiologist for Communicable Diseases
Wisconsin Department of Health Services
