University expands wastewater early detection program, asymptomatic testing kits and exposure notification system
UC San Diego’s nationally recognized, evidence-based Return to Learn program employs a comprehensive suite of education, monitoring, testing, intervention and notification tools that no other university is using. And the program continues to expand—including a recent introduction of weekly self-administered student testing kits, growth of the campus’s wastewater viral monitoring program and widespread use of the cellphone-based CA COVID Notify exposure notification system.
The expansion of the program comes as COVID-19 cases surge throughout the nation.
“While UC San Diego is one of the few colleges in the nation with low rates of infection and a large student body on campus, the university remains vigilant to reduce transmission of virus in our community to the greatest extent possible,” said UC San Diego Chancellor Pradeep K. Khosla. “Our multi-layered strategy provides resiliency along many dimensions of the Return to Learn plan.”
Throughout fall, the campus’s multifaceted, proactive strategies to detect and prevent transmission of SARS CoV-2 proved effective. UC San Diego has more students on campus than any other college in the state with nearly 10,000 living on campus and thousands more living off campus. Yet the university has maintained an average positivity rate between 0.17% and 0.43% among on- and off-campus students during the start of its fall quarter (Oct. 1 to Nov. 29). San Diego County’s average positivity rate was between 2.7% and 6.1% in that same time frame.
Return to Learn centers on risk mitigation, viral detection and intervention, with the size and scope of health intervention strategies—such as the campus wastewater early detection system—greater than any other university in the nation.
Wastewater detection program soon to monitor entire campus
The campus first started monitoring wastewater outflow during the summer with six wastewater samplers and increased capacity to 52 samplers on Nov. 22. The additional samplers cover more than 100 residential buildings. In the coming months, the campus will deploy up to 200 samplers to cover the entire campus.
“This wastewater testing system is a way to stay one step ahead of the virus on campus at a time when there is increasing viral activity in the county,” said Return to Learn project co-lead Natasha Martin, associate professor of medicine at UC San Diego School of Medicine. “With wastewater, we are essentially running pooled testing of every student in the monitored buildings every day. The critical part of the program is that when we get a positive wastewater signal, we notify those in the buildings draining wastewater into the manhole where we detected the positive signal, and we encourage them to come in and get tested. Those who are positive can move into isolation housing.”
The new samplers detected traces of the novel coronavirus coming from nine different areas on campus on Nov. 23 and Nov. 28. University leaders quickly notified residents in those areas to get tested as soon as possible. After the building wastewater notifications were distributed, more than 700 students were tested in the notified buildings.
As of Nov. 30, three students were identified as shedding virus in buildings covered by the alert, likely contributing to three of the nine different areas which detected traces of the novel coronavirus.
Martin added, “We have already had several successes in alerting buildings to a possible infected resident from the wastewater, and subsequently identifying a shedding individual among those buildings. This shows our wastewater program is working.”
In September, the campus quickly detected the virus at Revelle College and tracked it back to two asymptomatic people who might have been the source. The university continues to monitor the areas where active virus was recently detected to investigate if the traces have been resolved by identification and isolation. UC San Diego has reserved more than 600 units in two separate buildings for quarantine and isolation housing.
“The wastewater sampling is highly sensitive, and even one infected resident can generate a positive signal in the wastewater, which subsequently turns negative after the resident is moved to isolation housing,” Martin said. “By combining wastewater monitoring with weekly asymptomatic testing, we are seeking to identify and isolate cases before they become outbreaks.”
Martin says that if an individual tests negative on Monday and somehow picks up the virus on Tuesday, UC San Diego can detect it that day through wastewater surveillance. As soon as virus is detected by a monitoring station, the university releases an alert notice asking community members who live in or visit the area to be tested as soon as possible. “This allows us to get the source of an outbreak at a much quicker rate than by relying on weekly testing alone.”
UC San Diego’s wastewater expansion will continue in the coming weeks, and the effort is significant. Samples have to be collected physically every day and delivered to the Knight Lab at the Center for Microbiome Innovation, which developed the advanced technologies to conduct wastewater tests on a large scale. Center director Rob Knight and his research team personally collected samples over the Thanksgiving holiday weekend to garner the critical data.
“We have a very robust, ambitious plan with a lot of logistical challenges, but we are already seeing the potential of this program to identify undetected individuals earlier than through routine asymptomatic testing,” Martin said. “This work is critical, especially as case rates rise within the greater San Diego community.”
Weekly testing to include self-administered test
In light of the recent rise in cases around San Diego County, the campus has recommended students and employees participate in an asymptomatic test on a weekly basis at no cost starting Nov. 30. Students living on campus and attending in-person classes are still required to test every 12-16 days.
The campus has more testing capacity than any other university in the state, with two labs processing the tests—the Center for Advanced Laboratory Medicine (CALM) and Expedited Covid IdenTification Environment (EXCITE). On average, UC San Diego processes about 1,000 to 1,500 tests per day.
“By having access to this much needed testing capacity we can systematically test key populations on campus in our asymptomatic testing program and still have more than enough reserve capacity to substantially increase testing in specific locations identified by the wastewater testing program,” said Dr. Robert “Chip” Schooley, professor in the Department of Medicine at UC San Diego School of Medicine and co-lead of UC San Diego’s Return to Learn program.
Additionally, the campus piloted a self-administered asymptomatic COVID-19 test for undergraduate and graduate students. Test kits can be picked up and returned within 72 hours—allowing students to test at a time and location of their choosing.
“Our goal is to develop multiple testing options that will enable our community to test with minimal inconvenience close to where they live, work or study,” Schooley added.
Students can now pick up and drop off a testing kit between the hours of 9 a.m. to 4 p.m., seven days a week at Seventh College, Nuevo East and the Price Center Ballroom B—and at additional locations beginning Dec. 7. The tests will be made available soon at vending machines, which will be placed at 20 locations across campus, which students can access by swiping their student ID. Self-administered testing will also become available for staff in winter quarter.
Paving the way with tech to save lives across the state
UC San Diego successfully piloted the CA COVID Notify app throughout the summer and early fall. The technology augments and expedites traditional contact tracing. Over 18,000 UC San Diego staff and students—more than 50% of the on-campus population—are now using the system. The program uses a smartphone’s Bluetooth capabilities to alert people if they have come in contact with someone who tested positive for the novel coronavirus in the last 14 days.
UC San Diego Health is partnered with the California Department of Public Health to plan a possible statewide deployment of the app. The exposure notification system was made available to students, faculty and staff members at UC San Diego in late September along with UC San Francisco in early October and was expanded in mid-November to five additional University of California campuses. On Nov. 23, the technology was also offered to all recent patients within the UC San Diego Health System, growing the user base by up to 350,000 in the San Diego region.
The expansion couldn’t come at a more critical time, according to Dr. Christopher Longhurst, chief information officer and associate chief medical officer at UC San Diego Health, and clinical professor of Medicine and Pediatrics.
“With new cases and hospitalizations surging across San Diego and the rest of the state, we need to deploy every weapon in our arsenal,” said Longhurst. “This privacy-preserving tool has already been shown to help, and there is no downside to making this available as widely as possible on a voluntary basis.”
More than 20 alerts have been issued on campus since the pilot was introduced, helping campus residents and visitors alike learn they may have been exposed.
When the program is eventually deployed across the state, it will be a major boon to contact tracing for California’s nearly 40 million residents.
“UC San Diego Health worked with elected officials to advocate for this technology, and piloted it for the entire state,” said Longhurst. “I am very proud that we have been asked to help lead statewide expansion if and when it is approved by the governor’s office.”