COVID-19 Health Alert # 16:
Quarantine of Wisconsin residents exposed to COVID-19 is an essential prevention strategy
Bureau of Communicable Diseases, September 9, 2020
- DHS recommends a 14-day quarantine for all Wisconsin residents who were in close contact with a person with COVID-19.
- Close contact is defined as being within 6 feet of an infectious person for 15 minutes or more, unless the uninfected person was using appropriate PPE in a health care setting or similar environment.
- No employment sectors are considered exempt from the quarantine of exposed workers. Quarantine requirements may be modified in circumstances when excluding a person from work could result in an imminent threat to patient care, public health, or public safety. These circumstances should be approved on a case-by-case basis in consultation with local or state public health officials.
- In educational settings, strict adherence to quarantine requirements for students, educators and staff is necessary to minimize the risk of COVID-19 outbreaks.
Asymptomatic transmission of SARS-CoV-2 is known to be an important driver of the COVID-19 epidemic. Based on the best available data, it is currently estimated that 40% of COVID-19 cases are asymptomatic and that 50% of all COVID-19 infections are the result of asymptomatic or pre-symptomatic transmission. Prevention of infection due to asymptomatic transmission requires a multi-faceted strategy that includes widespread testing to identify and isolate cases, contact tracing to detect individuals who have been potentially exposed, and consistent application of quarantine rules.
Quarantine is the mandatory separation and restriction on movement of people who are not ill, but have been exposed to a communicable disease, to prevent transmission of infection. Quarantine is especially important for preventing and containing outbreaks of infections that can be transmitted from individuals who are asymptomatic or pre-symptomatic and may unknowingly spread the virus to others. While disruptive, excluding individuals who have been exposed to SARS-CoV-2 from work or school is a critically important strategy for reducing the impact of COVID-19. To strengthen our statewide containment strategy and prepare for the possibility of a worsening epidemic during the fall and winter months ahead, DHS is reiterating our commitment to the role of quarantine and clarifying our guidance related to its implementation in different sectors.
Health Care and Public Safety
The high risk of transmission of SARS-CoV-2 in hospital and long-term care settings was described early in the epidemic. Fortunately, nosocomial transmission has become less frequent in health care settings with widespread use of droplet precautions, including universal face mask and eye protection for all clinical care. While it is uncommon for health care workers to require quarantine because of exposures in the workplace, those working in areas with high levels of community transmission of COVID-19 may become exposed and potentially pose a risk to others if they develop infection. The safest approach to managing COVID-19 exposure of health care workers is to require 14 day home quarantine, similar to all employment sectors. In some instances, however, health care organizations have determined that excluding staff from work would result in staffing shortages which interfere with their ability to deliver appropriate levels of care. In this context, DHS recommends the following:
- Health care workers are not considered exposed and in need of quarantine if they have cared for a patient with COVID-19 while appropriately using PPE (i.e., contact and droplet precautions for all care, and airborne precautions if performing aerosol generating procedures).
- If a health care worker is found to have had close contact with a person infected with COVID-19 in a household or community setting, they should be excluded from work for 14 days unless the health care organization determines that doing so would prevent safe clinical operations.
- DHS recommends that health care organizations modify requirements for home quarantine of exposed workers on a case-by-case basis, rather than as a matter of policy applying to all staff in all clinical areas.
In addition to health care organizations, other employment settings may also find it difficult to exclude staff from work without creating a risk to public safety. Organizations employing first responders, police and fire departments, and correctional facilities may also to need modify the usual practice of voluntary home quarantine in the event that staff become exposed to COVID-19. Similar to health care settings, workers in public safety roles should not be automatically exempted from quarantine. Rather, agencies should consult with state or local health departments to determine whether and when work exclusions constitute an imminent threat to health or safety. If workers in these settings are asked to return to work during their quarantine period, the following measures should be in place:
- Daily symptom monitoring and documentation of results should be implemented for all workers.
- All workers in the environment should adhere to recommended infection control practices including wearing a face covering while indoors, hand washing and disinfection of surfaces, and physical distancing to the greatest extent possible.
- Workplaces may be asked by local health departments to provide written attestation as justification for waiving work exclusion requirements.
Other Employment Sectors
Public health departments should not recognize any employment sectors as exempt from the requirement to quarantine. Unlike guidance recently modified by the U.S. Department of Homeland Security, which indicates workers in a broad range “critical infrastructure” sectors may be exempted from quarantine, DHS recommends that workers in all settings be required to quarantine (see exceptions noted above).
Individuals who have been in close contact to a person with COVID-19 may continue to do remote work, or engage in work-related activities out of the home that do not involve either close contact or sharing an indoor space with other people who are not part of their household.
Prior research on influenza and other respiratory viruses shows that disease transmission in school settings can be important drivers of local epidemics. While some school districts and other educational institutions have decided to cancel in-person instruction at this time, many are preparing to continue in-person instruction and other school activities. Supporting in-person education in the safest possible way will require commitment by families, students, and all school staff and administrators to work together to identify any cases of COVID-19 as early as possible and to participate with contact tracing efforts to identify all people who have been in close contact with cases.
Children and adolescents are more likely than any other age group to be asymptomatic when infected with COVID-19, making disease containment challenging. Identifying all students and staff with possible exposure to COVID-19 and requiring immediate quarantine is therefore especially important in educational settings, where outbreaks may develop and spread through numerous waves of infection without detection.
School nurses who are trained in the appropriate use of medical-grade PPE are not required to be quarantined if they adhere to appropriate transmission-based precautions when in contact with students or staff who are found to have COVID-19.
Modifications of quarantine practice that are NOT endorsed by DHS
DHS recognizes that other state and federal public health agencies have endorsed a range of modified policies and practices related to quarantine. After close review of the scientific evidence, and in consideration that the ongoing high level of COVID-19 disease activity in Wisconsin, DHS has considered numerous such strategies proposed elsewhere and has explicitly decided to NOT implement these strategies.
- The recommended duration of quarantine should never be shortened because a COVID-19 test performed during the quarantine period is negative. DHS continues to recommend that all individuals in close contact with a known case be tested. The purpose of this testing, however, is to identify unrecognized cases needing further investigation; testing is not useful for determining when it is safe to return to work or school. Numerous studies confirm that infection can occur at any time during the 14 day incubation period. An individual who tests negative on day 7 of the quarantine still has significant risk of developing infection and spreading it to others at any time during days 8-14. Under limited circumstances, intensive serial testing can be used to facilitate early return to work, but this should be approved by local public health officials prior to implementation.
- Cloth face coverings, although an important community-level intervention to reduce the overall probability of exposure to COVID-19, should not be taken into account when determining whether a person was in close contact with a case. Only medical-grade PPE, worn by individuals trained in its use, is considered able to reduce the risk of transmission sufficiently to make quarantine unnecessary in the event of close contact to a person with known COVID-19.
Thank you for your collaboration and ongoing commitment to the health of the people of Wisconsin.
Ryan Westergaard, MD, PhD, MPH
Chief Medical Officer and State Epidemiologist for Communicable Diseases
Wisconsin Department of Health Services