The Snohomish Health District said it has seen two record-setting days of new confirmed cases received in a single day. On Wednesday, the health district received 182 new cases. These high numbers mean that the rolling two-week case rate through Nov. 7 will see another significant increase, the department said.

In an announcement Friday, the health district also pointed to a new report by the Institute for Disease Modeling (IDM) — issued by the Washington State Department of Health — that quantifies how various diagnostic screening scenarios could help mitigate the risk of COVID-19 transmission associated with reopening schools. It affirms that while returning to in-person instruction is not zero-risk, the risks could be significantly reduced through school-based preventive measures, cohorting, hybrid scheduling, and a phased-in approach that brings back K-5 grades first.

In the context of such preventive measures, the report did not find additional benefit from routine testing of asymptomatic individuals in the school setting. For more information on the report, see Department of Health’s press release.

According to the health district, the report continues to support the fall guidance and decision tree released by state health department and the Office of Superintendent of Public Instruction, and the district’s Oct. 20 guidance has not changed:

• Continued distance learning is still strongly recommended, with limited in-person learning for younger learners (especially K-3) and high need students (e.g., disabilities, homelessness, farthest from educational justice)
• In-person learning for older students is discouraged, except high need students, particularly at the current level and trajectory of COVID-19 activity in the community.
• Strongly recommend canceling or postponing most in-person extracurricular activities, including sports, performances, clubs, events, and such, with the option to allow extracurricular activities in small groups of six or fewer students.

“Risk assessment and values vary widely across interested parties, with some wanting much more in-person learning and others much less,” said Dr. Chris Spitters, Health Officer for the Snohomish Health District. “As the local health officer, my role is to help local school leaders apply to Snohomish County the guidance provided by DOH and its subject matter experts.”

All pathways forward carry some risk and uncertainty in the context of the COVID-19 pandemic. The absence of a zero-risk pathway, the novelty of the situation, and the residual uncertainty in the evidence base are implicit factors affecting all of our respective roles in this.

These processes are also influenced by risk tolerance, values, and other factors that vary from family-to-family and community-to-community. The Health District’s role is to provide K-12 leadership with what we know about the COVID-19 risks and the means to mitigate them. It is then in the school leadership’s domain to take that guidance and incorporate it into their decision making and operations with respect to the students’ education.

The health district’s guidance to schools focuses on elements within the DOH’s existing framework for K-12 learning:

• Focus in-person learning on those special needs and elementary school students least likely to be able to learn remotely.
• Implement rigorous programs of daily symptom screening, face coverings, distancing, hand hygiene, environmental disinfection, and optimizing ventilation (to exhaust indoor air and entrain outdoor air as much as feasible).
• Ensure follow-up testing of students and staff identified as suspected cases through daily screening.
• Follow through with contact investigations and quarantines of cases and contacts, respectively, in the school community.
• Follow DOH and OSPI guidelines, including those for when to close a classroom or school.
• Defer plans for in-person learning among older students (i.e., middle and high school).
• Maintain frequent communication and close collaboration between the Health District and school leadership.
• Reassess if school-based transmission exceeds control capacity, schools appear to be catalyzing or amplifying community transmission, or if a hospital surge threatens acute care capacity in the county.

The current, ongoing community-wide increase in COVID-19 transmission has not been linked to transmission in schools so far, but rather has been driven by transmission in private social gatherings where masks are not being worn and in some workplaces with social distancing or other prevention deficits, the health district said. While sporadic cases and clusters of cases have been and will continue to be detected in school settings (both with and without in-person learning), mitigation and control efforts have been successful.

In a briefing Nov. 5, the state health department noted that school-based outbreaks have been reported in just 32 instances with 110 secondary cases statewide —a very small proportion of the community-wide transmission that is occurring. In Snohomish County, there have been six school-based outbreaks involving 18 total cases. There have been more cases involving students and staff, but the exposure was community-acquired or close contact in a setting other than the school, the health district said.

These findings are consistent with findings in Institute of Disease Modeling study, suggesting that incorporating the full suite of mitigation efforts listed above will be highly effective in limiting school-based transmission and its impact on community transmission.

“The public health community’s interpretation of the COVID-19 literature is that the preponderance of empiric data suggests that while transmission from elementary school-aged children may occur, it is substantially lower in relative magnitude compared to older children and adults,” added Spitters. “Our current thinking is that schools conducting cohorted, hybrid in-person learning with the above prevention measures in place are unlikely to experience uncontrolled transmission, nor are they likely to exacerbate community based transmission.”