As confirmed coronavirus cases continue to increase locally, schools and universities are amping up their prevention efforts, from preparing for online learning options and conducting intensive cleaning to urging cancellation of large events.

The Palo Alto school district, which sent home from school last week two students whose parent had been exposed to the coronavirus, has implemented extra cleaning of the students' schools, Palo Alto High School and JLS Middle School. Custodial staffs at every campus are following recommended cleaning procedures daily, "with extra effort on areas considered high-risk," such as bathrooms, athletic areas, cafeterias and the nurse's office as well as "high-touch points" such as door handles, hand railings, lockers and shared desks, the district announced.

Superintendent Don Austin declined to state whether the two students had been tested for the coronavirus, citing their privacy, but said that the district was following direction from the Santa Clara County Public Health Department.

Austin was also authorized by the school board president to suspend a board policy that prohibits alcohol-based cleaning products and immediately ordered alcohol-based hand sanitizers for schools, he wrote in an update to families and staff on Wednesday.

The district has suspended all school-sponsored international field trips and is re-evaluating local field trips daily, Austin said. The Greene Middle School band left Wednesday for a trip to Disneyland near Los Angeles, despite reported concerns from some parents who fear the traveling students could be exposed to or bring back the virus. (Seven cases have been confirmed in Los Angeles County.) The school district took the temperatures of all students and adults attending the field trip before boarding a bus, according to the district, and Greene's principal met with the students to review "proper health protocols and responsibilities." Music teachers told parents in an email they planned to wipe down the surfaces of the bus with antibacterial wipes before boarding and remind students to wash their hands thoroughly at each rest area and throughout the day. The teachers said they had a "limited supply" of hand sanitizer and antibacterial wipes and asked parents to send their children with extras, if possible.

The county has advised against canceling domestic field trips, though Austin said he is "not sure that this advisement will hold up for much longer."

Palo Alto Unified has no plans to close schools at this point and is not providing online instruction to students whose parents might choose to keep their child at home.

"No school in our county is closing at this time," Austin wrote in his update. "We have no confirmed cases and no practical reason to close our doors. ... Everyone is fully engaged and trying to make the best decisions possible for our students, staff and community."

The private Menlo School in Atherton closed for the rest of the week after a staff member interacted with a relative who tested positive for the novel coronavirus on Tuesday, March 3. The school is preparing for online learning if the closure lasts beyond the weekend.

Castilleja School in Palo Alto is canceling classes on Monday, March 9, and asking all students to work from home so teachers can prepare for "synchronous distance learning should the need arise," Head of School Nanci Kauffman and Chief Financial and Operating Officer Kathy Layendecker wrote in a message to parents. The school is not aware of any students or staff who have been exposed to the coronavirus.

If the private all-girls school closes, Castilleja plans to provide remote learning for all students and will treat it "as regular school days with required attendance, participation and timely assessments."

The school is also canceling a middle school dance this Friday evening and has convened a "COVID-19 Command Team" to lead the school's safety, prevention, monitoring and communication efforts.

The school is asking all Castilleja community members to inform Layendecker of international travel and if anyone living or working in their household has been exposed to or diagnosed with the coronavirus.

The Ravenswood City School District is providing masks to students experiencing symptoms and school offices will be using logs to track such students, interim Superintendent Gina Sudaria wrote to families this week. Schools are stocked with thermal skin thermometers, hand sanitizer, soap, paper towels and tissues. Ravenswood is in San Mateo County, where there have been two confirmed coronavirus cases as of Wednesday. The county manager declared a local emergency there on Tuesday.

"In the event the pandemic worsens, we may adopt other precautions such as screening visitors based on medical and epidemiological advice," Sudaria said.

Los Altos Hills community college Foothill College is "working under the assumption that we will be open as normal for the foreseeable future," President Thuy Nguyen wrote to students, but is preparing training videos for students, faculty and staff on how to use Zoom, which provides software for remote conferencing services, and online education platform Canvas should the need arise for remote learning. The community college has not canceled any events but said that faculty and staff members' plans to attend external conferences have been canceled.

The Foothill-De Anza Community College District has convened meetings this week with representatives from both community colleges to discuss their response to the coronavirus, including how to "maintain instructional continuity" and support students if the campuses have to close.

The Centers for Disease Control and Prevention (CDC) has recommended K-12 schools and child care programs "work in close collaboration and coordination with local health officials to make dismissal and large event cancellation decisions."

"Schools, working together with local health departments, have an important role in slowing the spread of diseases to help ensure students have safe and healthy learning environments," the CDC's interim guidance for schools stated.

Stanford University, meanwhile, is urging cancellation or postponement of university events between March 4 and April 15 that involve more than 150 people — not including regular academic courses, according to a Tuesday announcement from Russell Furr, associate vice provost for environmental health & safety. Furr is leading a new emergency operations organization Stanford activated this week to coordinate the university's response to the coronavirus.

An alumni day scheduled for this weekend and a Stanford Institute for Economic Policy Research summit have been canceled, among numerous other university events. The Office of Religious Life has suspended public worship services.

Some events that will have fewer participants but will be held in confined spaces should be reconsidered, he wrote. He urged organizers to consider other factors such as the age and health of expected attendees and the need to clean the space after the event. Stanford is also suggesting the use of phone calls or videoconferencing instead of large meetings.

"At Stanford, we are aiming to balance two imperatives: We are seeking to continue our work of education and research to the greatest extent possible while also keeping our community safe and protecting the health of communities beyond our campus, as well," Furr wrote.

At this time, all Stanford athletic competitions are proceeding as scheduled, though with limited public attendance, the university said.

Stanford is also planning more continual cleaning in common areas and on commonly touched surfaces. "Elevated cleaning" will be required in academic, dining and housing spaces, Furr wrote.

No one traveling from China, South Korea, Italy, Iran or any other country with a CDC Level 3 travel health restriction is allowed to be present on the Stanford campus unless he or she completes a 14-day self-isolation immediately upon arrival in the U.S. This includes all people, including children, with or without symptoms, Furr wrote. It also applies to visitors to Stanford.

By Wednesday, Stanford decided to put more travel restrictions in place, banning university-sponsored international travel to any country through April 15. The university is "strongly" recommending against personal travel out of the country and against "non-essential university-sponsored domestic travel to reduce Stanford's contribution to the potential spread of infection to other areas," Furr wrote in a March 4 message.

Stanford asked people to register any travel plans with the university.

After ending a winter quarter study abroad program in Florence, Italy, early Stanford announced on Wednesday that all spring quarter international programs would be suspended temporarily. The Centers for Disease Control issued guidance this week for higher-education institute to consider suspending or postponing study abroad programs.

"Contingency planning is actively underway on a number of fronts to anticipate the evolution of the virus' spread," Furr said.

Online petitions have emerged calling on both Palo Alto Unified and Stanford to take more stringent precautions.

Palo Alto parents have asked the district to start spring break early, extending it to two weeks, and to provide online learning options so students can stay home. More than 1,700 people had signed this petition as of Thursday.

A petition started by a student group called Stanford Against Coronavirus described the university's education efforts on the coronavirus as "deficient at best" and proposed a contingency plan, including encouraging faculty to conduct classes digitally as much as possible, to not require attendance for classes with more than 50 students and to provide face masks for students with flu symptoms. As of Thursday, more than 2,000 people had signed the petition.

"If Stanford University hesitates to take immediate and appropriate actions to protect its 16,520 students and 14,060 faculty and staff members, COVID-19 will have a great potential to spread throughout the campus, jeopardizing the lives of us all," the petition states.

On Wednesday, Furr acknowledged "there are many questions from students and faculty about issues including course attendance, technology options for faculty in delivering course material, administration of final exams and other course-related matters. The university is working through these issues right now, in coordination with school and faculty leadership, and we will be providing more guidance shortly."

Confirmed coronavirus cases continue to rise in Santa Clara County. As of Friday, the latest total is 24.

Read our latest updates on local coronavirus cases here.

Find comprehensive coverage on the Midpeninsula's response to the new coronavirus by the Almanac, Mountain View Voice and Palo Alto Online here.