Classes have been back in session for less than a week after winter break and local schools are reporting record numbers of COVID-19 cases among students and staff, as the highly contagious omicron variant spreads locally.

Some districts, including the Mountain View Los Altos Union High School District, have abandoned sending out close contact notifications, saying it's logistically impossible with cases at record highs. They are instead warning families that all students should assume they have been exposed to the virus and get tested weekly.

"It is absolutely the highest (number of cases) we've seen by a long shot," MVLA Associate Superintendent Leyla Benson said. "When we were having a few cases a week, it was a much different landscape. This variant is much more contagious."

The district has had 45 students and 13 teachers or other adults who were on campus this week and subsequently tested positive for COVID-19, as of Friday morning. The district has roughly 4,500 students.

There also is a group who contracted the coronavirus over winter break, but found out in time to avoid coming to school. In total, the district counted 156 students and 26 adults with positive tests, Benson said on Thursday. She cautioned that the true numbers are likely higher, because people are only required to report a positive test result if they have been on campus.

In the fall semester, the district had no more than six students report positive tests in a single seven-day period.

Other local schools have similarly seen big increases in COVID-19 cases this week. Palo Alto Unified plans to publish updated case numbers later today, Jan. 7, but Superintendent Don Austin said Thursday evening that he expects over 200 cases, possibly more. By Friday morning, Austin revised his estimate to roughly 300 cases. Those only count students and staff who came to campus. In the fall, the district saw weekly case counts in the single digits among its 10,500 students.

The smaller Los Altos School District, which serves roughly 3,300 elementary and middle school students, also has seen cases increase. This week, 26 students and four staff members have tested positive. That may include some who never came to campus, Superintendent Jeff Baier said. Over the two weeks of winter break, 83 students and 26 staff tested positive.

In the K-8 Mountain View Whisman School District, which has 4,500 students, 23 staff and 33 students are listed as having tested positive in the past seven days, as of Friday morning, Jan. 7.

The spikes in COVID-19 cases at local schools follow a broader omicron-fueled surge in the pandemic both locally and nationally. Santa Clara County is seeing its highest numbers of COVID-19 cases to date, with a seven-day rolling average of 1,918 cases as of Thursday.

Trying to avoid classroom or campus closures

With cases at record highs, districts are grappling with how to safely keep students learning in person, even as more of their classmates and teachers test positive. After experiencing over a year of remote learning, education officials have stressed that they want students on campus, if at all possible.

"We had heard very clearly from the community the importance of in-school instruction and the effectiveness of in-school instruction," Benson said. "We know that this is the model that is best for student learning."

At the same time, local school administrators acknowledge that it is possible some classes will have to move online, at least temporarily. The biggest concern, officials say, is being able to maintain adequate staffing levels to keep classrooms open. Schools, like many industries, have been facing staffing shortages. Substitute teachers have been particularly hard to find.

Thus far, Palo Alto Unified, MVLA, Mountain View Whisman and Los Altos have all avoided having to move any classes online.

"It's manageable right now and as long as that remains true, we're open," Austin said, adding that he thought they would have had to close classrooms by now.

Baier called staffing the "linchpin" that is making in-person school possible, but said his district is currently in a reasonably good place.

"We are certainly stretched thin, but we've been able to make it work thus far," Baier said.

Beyond staffing, there's also the possibility that a classroom, or theoretically an entire school, could close if COVID-19 case numbers get too high. Unlike earlier in the pandemic, the state has not currently released specific metrics for when a school would have to close, instead saying that the process should be "guided by local epidemiology, with particular attention paid to concern for in-school transmission."

At the same time that staffing has proved a challenge, some districts are also moving to shorten the quarantine guidance for teachers and other staff who test positive, allowing them to return to the classroom more quickly. Rather than a mandatory 10-day quarantine, the Centers for Disease Control and Prevention has issued guidance that allows for a five-day quarantine, if the person doesn't have symptoms and tests negative on the fifth day.

That change is being adopted by some Santa Clara County districts, including Palo Alto Unified. MVLA and Los Altos are both currently making the transition, while Mountain View Whisman spokesperson Shelly Hausman said Thursday that the district is still using the same quarantine rules it did in the fall.

Although MVLA plans to adopt the new quarantine rules, Benson noted that they are more complicated, because they require a negative test on the fifth day, while the prior guidelines called for a flat 10-day quarantine, with no need to test again before returning.

The Santa Clara County Department of Public Health did not respond to specific questions from this news organization about its current quarantine guidelines and metrics for school closure, and instead said to refer to state regulations.

Abandoning contact tracing efforts

At the middle and high school levels, where students rotate between classes throughout the day, a single case can lead to over 100 close contact notifications. That has led Palo Alto Unified and MVLA to suspend sending out individualized close contact letters. Both districts are urging families to get regularly tested, with on campus testing options available.

"You would, as a parent, have the very real potential of receiving a contact letter every single day from us (for) however long this surge lasts," Palo Alto Unified Superintendent Don Austin said. "That's not going to add any value for anybody."

Without those close contact notifications, ensuring students actually get tested is a potential hurdle. Individualized close contact letters spell out specific testing requirements for students to remain on campus.

"What we need to convey to our community is that currently there is a prevalence (of the virus) in our schools, which means that statistically it is very likely that your child has come into close contact with someone, so the safest approach is to continue testing," Benson said.

The Los Altos School District is currently continuing with its contact tracing efforts, but Baier said district officials are looking for ways to streamline the process as more people are testing positive.

"With more cases, getting the letters out for the variety of scenarios in a timely fashion is just really difficult," Baier said.

Mountain View Whisman is also continuing to contact trace and send out close contact notifications, Hausman said.