A little over a week ago, the Oregon Health Authority reported 245 schools with at least one recent COVID-19 case. This past week, the number rose to 329.

With about a month left in the school year, Oregon continues to deal with a COVID-19 surge, and school cases are a part of that.

Health officials say that increased community cases may lead to increased COVID-19 cases reported in schools, though they contend that does not necessarily mean transmission in schools.

So what do these numbers mean, and how accurate are they?

Where outbreaks are happening

Of the schools with COVID-19 cases, OHA senior health advisor Tom Jeanne said in the last couple of weeks, 194 K-12 schools had just one case. There were two or more cases at 73 schools.

Oregon health officials consider a single case appearing at a K-12 school as an outbreak.

But if a school has two or more cases, OHA says that does not always mean transmission happened within the school.

Analyzing data from January to the end of April, out of 866 school-associated outbreaks (467 reported outbreaks of one case, and 399 reported outbreaks of two or more cases), OHA found 8.6% reported transmission within a school.

“Of all those cases we’re seeing in schools, a very small percentage of them are associated with an actual school outbreak,” Jeanne said. “In other words, most of them — the COVID was acquired outside of the school.”

Oregon’s high schools have the majority of multiple cases.

The largest numbers of student cases are in Bend-La Pine schools, specifically the district’s high schools. Between Bend and Summit high schools there are 90 student cases and three staff/volunteer cases, according to OHA’s latest report.

The large Central Oregon district, the largest in the state to go “all-in” and reopen to all students, is changing its schedule in response to COVID-19 spread and its impact on the schools and students.

“The number of students and staff who are unable to attend and work in our schools is at an all-time high,” wrote interim superintendent Lora Nordquist in a statement earlier last week.

“Hundreds of students throughout the district have been quarantined as a result of rules that call for quarantine of ‘close contact’ to those with COVID-19.”

Some of these cases are coming from school sports, or social gatherings outside of school.

In her note, Nordquist said COVID-19 spread is connected to “parties, carpooling, BBQs, and social gatherings.”

In northeastern Oregon, an outside-of-school, community prom has been cited as a possible source for 11 student COVID-19 cases and a two-week shutdown at Wallowa High.

Jeanne said with a COVID-19 surge in Oregon — and more students in school in person — comes more cases.

“That’s part of the reason we’re seeing more cases tied to schools,” Jeanne said.

But Jeanne maintains that there are higher risk settings, including household gatherings, social events and sports, especially because schools are required to follow state COVID-19 protocols..

“We remain convinced that having schools open is really an important thing. ... We’re watching it closely right now, I don’t have any great concern that schools are superspreading places or places where we’re seeing an especially high number of transmissions. … It’s really what’s happening related to schools.”

There are school systems around the world that have kept schools open throughout the last year, noted Chunhuei Chi, Oregon State University professor and director of OSU’s Center for Global Health.

Chi cites Taiwan, a country that hasn’t closed schools at all in the pandemic, as an example of a school system that has implemented safety measures — from masks and temperature checks, to constant sanitizing, to keeping windows open — as a model for Oregon.

Oregon schools have implemented a lot of the same measures through the Ready Schools, Safe Learners guidance. But unlike Taiwan, community transmission in Oregon right now continues to be high, compared to where it was a few months ago.

Outside of schools, it can be harder to enforce some of those more informal community or social gatherings between students and their families. Jeanne with OHA acknowledges the challenge, and that reopening schools may have made those gatherings seem less risky.

“Once kids go back to school, they’re probably seeing more friends and they want to naturally do those things that we do around school and outside of school,” Jeanne said. “It’s limited our ability to directly affect all that stuff. People will do that stuff — that is a real challenge.”

Jeanne said in the next few weeks, the weekly report will separate “true” outbreaks, where there has been transmission, from schools with cases but no evidence of spread happening at school.

But even the state’s data on COVID-19 cases connected to schools can be confusing.

Between state and local reports, COVID-19 case numbers can be inconsistent

The Oregon Health Authority’s COVID-19 weekly outbreak report has many moving parts. The report includes outbreaks in workplaces, child care facilities and senior living communities.

As soon as a report of a COVID-19 case comes in, it gets into the state’s “queue.” Local and state public health departments can access that information in a database. From there, the report is processed by an epidemiologist, then gets tallied into OHA’s weekly report.

Individual school districts are also posting COVID-19 case information publicly, but their dashboards vary from district to district.

In Bend-La Pine, where the state’s report lists 93 recent cases at two high schools, the district’s own dashboard reports 74 recent cases between five high schools. The district said that number is more recent than OHA’s information.

The COVID-19 dashboard for Portland Public Schools lacks some of the specifics that are posted by other districts. In nearby Washington, Vancouver Public Schools’ dashboard includes weekly and cumulative COVID-19 case totals, as well as a breakdown by student and staff cases, with an indication of whether transmission occurred in school or not. There have been 91 cases district-wide since Sept. 1, the first day of the school year.

The Beaverton School District’s dashboard is less detailed than Vancouver’s, but still separates staff and student cases. However, the data may not be completely up to date, because it’s compiled after information has come out in OHA’s weekly report. Those numbers come from local health department collaboration with school nurses.

Lags in reporting the data are an issue. It may be days before COVID-19 symptoms show up, days before a person receives a test result, and days before that positive case shows up in OHA’s report.

“There’s definitely a few days, in most cases … between when they first develop symptoms and when we actually get the report.” Jeanne said.

In OHA’s latest report, the most recent COVID-19 case is from May 2, three days before the report’s publish date. The “newest” school cases in the report are from April 30. That means these cases weren’t reported publicly until a week after they were found.

These higher school numbers mirror the surge in COVID-19 throughout Oregon that was still growing through the end of April. Numbers have leveled off some in May, but if that trend is also going to affect school cases, that hasn’t shown up in school data yet.

Shellie Bailey-Shah, Beaverton’s public communications officer, calls it an “imperfect system,” but said with the dashboard, the district wants to provide as much transparency as possible.

Portland Public Schools’ dashboard publishes “probable” cases on its web site, but it lacks information about COVID-19 cases that are confirmed by positive test results. The district said individual school communities learn about positive cases, and most of them have been reported by OHA. PPS also lists “impacted schools” — schools where COVID-19 has caused groups of students to move from in-person to online schools.

PPS reports its numbers on Mondays, two days ahead of the Oregon Health Authority

Most recent reports show numbers going up in PPS schools, and they’re likely missing some of the most recent cases at schools

First, there are inconsistencies in what shows up in the Oregon Health Authority’s weekly report. For example, in Portland, Cesar Chavez, Bridlemile, and Hayhurst school communities were notified of positive COVID-19 cases in April. The latter two cases were included in a Willamette Week story. Yet none of the cases are included in OHA’s report of active or resolved cases. PPS officials said they shared those cases with OHA.

OHA said it could be due to that lag in getting information through the various reporting layers.

Another underlying issue is that not all students, especially asymptomatic students, get tested. Schools are only required to offer on-site COVID-19 testing for symptomatic students or staff, or someone with a known exposure to a COVID-19 case.

Young people are less likely to develop COVID-19 symptoms, but they can still transmit the disease. It’s possible that more cases can be linked to schools than data shows.

At the same time, research suggests new COVID-19 variants may be more contagious in children than previous COVID-19 strains.

“We have seen statistics that the new variants, the B.1.1.7, originally in the UK, are more contagious, not just among adults, but among kids and teenagers,” OSU professor Chi said. “Teenagers and kids, when they are infected, on average they will be generally fine without symptoms or very mild symptoms, but not necessarily so for the adults.”

Even when showing symptoms, there may be barriers to testing a student at school. In Portland, some parents did not give permission for their students to be tested before schools reopened. If that’s the case, school staff can call for permission. The district said it also provides resources for free community testing sites as it sends the student home.

Once a case is confirmed positive, that person, and students or staff who were in contact with the affected person are required to quarantine. But if students are exposed to someone who tests positive for COVID-19, their household members aren’t required to quarantine.

Chi said that’s a hole in Oregon’s requirements that could be leading to more cases.

“If a student has been exposed to cases, … not just the student needs to be quarantined, the family also needs to be quarantined,” Chi said. “That’s a big hole, because there’s a potential if the student brings back the virus, there’s a potential the student can infect other members in the family, and then if the family are not quarantined, the family can continue to bring that to the community.”

Vaccines — and what else schools can do

Students 16 or older are now eligible for, and receiving the COVID-19 vaccine, and districts such as Portland Public Schools have been facilitating vaccine access for those older students. Last week, Pfizer officials said the U.S. Food and Drug Administration is expected to authorize its COVID-19 vaccine for children 12 to 15.

At least one school district, Eugene 4J, is already planning a clinic for 12- to 15-year-olds, as reported by KLCC.

With students vaccinated, that could mean fewer cases of COVID-19, and less risk in being back inside schools, or out together at social gatherings.

But that hasn’t happened yet.

Chi said until both students and their parents are vaccinated, there will continue to be COVID-19 cases associated with schools.

“It’s not adequate to just vaccinate teachers, because the students can get infected, and then bring that back to their parents,” Chi said. “Unfortunately, this is what we are seeing.”

The school year is almost over. With that comes summer school, summer camp and before long, the start of another school year that may look different than school pre-pandemic.

Jeanne said OHA and the Oregon Department of Education are working on updated guidance for summer programs and the fall.

He said the state continues to prioritize having schools open and offering in-person learning for students. But what happens outside of school continues to present challenges to safety and health for those same students, and their families.

“We’re not out of the woods yet.”