Schools can prevent most Covid outbreaks without routine testing, study finds

Schools can prevent Covid outbreaks without routinely testing attendees — that's if they take enough other precautions and community transmission is low, according to new report from the Institute for Disease Modeling.

The Seattle-based researchers looked at whether using Covid tests as a screening tool, as many K-12 schools and universities around the nation are doing, would help stave off outbreaks in schools that reopen in King County.

Computer models created by the Institute for Disease Modeling showed that routine testing was usually less valuable than preventive measures, such as reopening to younger students first and using hybrid schedules, which are currently recommended by the Washington State Department of Health. Other measures include state-mandated precautions, like mask-wearing, frequent hand-washing and sanitizing, thorough symptom screening, and adequate ventiliation.

With those precautions in place, and low rates of community transmission, only 2% of staff and students would be expected to get Covid at school or elsewhere over a three-month period, the institute found.

Without proper precautions, as many as an estimated 45% of staff and 30% of students could be infected over that same period.

State Health Officer Kathy Lofy said the ne study will help guide the state’s protocols for reopening schools.

But Lofy added that now is not the time for schools to increase in-person learning where Covid infection rates are sharply rising, like in King County.

The state Department of Health advises that schools avoid fully reopening in regions with 75 cases or more per 100,000 residents within a two-week period. As of last Saturday, King County had 135 cases per 100,000 residents. That's the highest rate in the county to date.