While the novel coronavirus poses the smallest risk to children and teenagers, a positive case in Hillsboro spooked families so badly more than 40% of students at South Meadows Middle School were absent Monday and Tuesday.

Nearly 43% of students, or 318, were gone Monday, district spokeswoman Beth Graser told The Oregonian/OregonLive.

Parents for 41 of those children called ahead to say their student was sick. A typical week in March sees about 70 absences per day, she said.

On Tuesday preliminary numbers showed 300 kids weren’t in class.

On Wednesday, Glaser provided finalized numbers for Tuesday’s absences. Turns out, 242 students, or 33%, were absent, she said.

Despite inquiries from parents and community members, officials in Oregon have been reticent to call for school closures even in buildings with confirmed cases of coronavirus, much less a wholesale shuttering of districts as was the case in neighboring Washington, which as of Tuesday has 18 times as many cases as Oregon and 24 deaths to Oregon’s zero.

That’s because schools offer a respite for students experiencing poverty and homelessness, officials with the Oregon Health Authority argue. Health care workers with school-aged children are needed to work the front lines of the disease, they said. In addition, if school close and children are cared for by parents or other elderly relative, they could spread the virus to that more vulnerable category of people.

Instead, districts across the state have adopted a set of guidelines issued by the agency to slow the disease’s spread.

In Hillsboro, teachers are giving children more time after lunch and recess to wash up and are also providing bottles of pump-style hand sanitizer in classrooms.

Educators in Beaverton are being more vigilant about asking students whether they’ve properly washed their hands after eating or playing outside.

“Schools, and especially elementary schools, run on such a tight timeframe, so they’re just making sure kids are getting that done” without extending lunch periods or recess time, District spokeswoman Maureen Wheeler said.

Neither district reported a noticeable uptick in absences Tuesday. In Beaverton, absenteeism was up about 2% over last year, Wheeler said.

Portland Public Schools spokeswoman Karen Werstein said a larger-than-normal share of teachers phoned in sick last week, although those numbers decreased Monday and were even lower Tuesday.

In Weston, the eastern Oregon city where a man confirmed to have contracted coronavirus attended a middle school basketball game, officials ordered a deep clean of the gymnasium by crews wearing hazmat suits.

But aside from that, Athena-Weston Superintendent Laure Quaresma said, it’s business as usual — or as close as it gets during flu season.

Oregon health officials recommend covering coughs and sneezes and that anyone showing mild symptoms should stay home and recover. They also say proper handwashing is among the most effective ways to slow the spread of the disease and Quaresma said Athena-Weston teachers and staff have emphasized what they call “good health habits.”

“We’ve got a big emphasis on handwashing and staying home when you’re sick. That educational piece is very big,” she said.

Despite a steady uptick in the number of presumed and confirmed coronavirus cases reported across the country, school closures remain rare, save for the three states with the most confirmed cases of COVID-19.

Nationally, 113 schools or districts have closed their doors over coronavirus concerns with another 26 scheduled to shutter, according to national education reporting outfit Education Week. On Tuesday, the outlet reported that 57 schools or districts serving 1% of the nation’s school children were closed.

Seattle Public Schools on Tuesday announced it would temporarily shutter Aki Kurose Middle School, the district’s first such closure despite its position near the epicenter of the coronavirus outbreak in the U.S, because an adult staff member tested positive for COVID-19. The nearby Northshore district closed all of its schools to conduct deep cleans shortly after the first Washington case was confirmed, The Seattle Times reported.

New York Gov. Andrew Cuomo announced that large gathering spaces, including churches and schools, within a one-mile radius containment zone will close for two weeks in New Rochelle. That’s where the state reported its first coronavirus fatality.

Closing a school as soon as its first student, parent or employee tests positive for a moderately transmissible disease like coronavirus, Yale University social scientist and physician Nicholas Christakis told Science Magazine, can reduce the number of transmissions by about 25% during an epidemic.

“By that time, they’ve probably transmitted it to other people,” he said. “It’s the tip of the iceberg.”

In Oregon, only Lake Oswego’s Forest Hills Elementary temporarily shuttered when a staff member was confirmed as the state’s first presumed case of coronavirus, reopening only after the employee had been away from the school for 14 days. The school reopened March 5 after a deep clean.

So far, there have not been any positive tests reported for Forest Hills students or employees.

Education officials from across the state, including education department head Colt Gill and state PTA President Kristi Dille, say the Oregon Health Authority made the right call in suggesting schools remain open.

In eastern Oregon, Athena-Weston’s Quaresma said the district wants to retain a sense of normalcy in its classrooms.

“We’re trying to be school as normal because bugs are always there. This is one that’s not well known, so we’re just using common sense without going into a panic,” she said.

Kale Williams of The Oregonian/OregonLive staff contributed to this report.

--Eder Campuzano | 503-221-4344 | @edercampuzano Do you have a tip about Portland Public Schools? Email Eder at ecampuzano@oregonian.com or message either of the social accounts above. Subscribe to Oregonian/OregonLive newsletters and podcasts for the latest news and top stories.