A key part of UC San Diego’s proactive Return to Learn strategy to detect SARS CoV-2 (which causes COVID-19) and reduce transmission of the virus is wastewater monitoring. The campus’s early detection system identified active virus in the wastewater outflow in the Revelle College area last Friday afternoon. The campus community was notified within 14 hours and targeted messages were sent to members in and around the Revelle community indicating they should be tested for the virus as soon as possible out of an abundance of caution.
The campus community acted immediately with more than 657 people tested over the weekend and as a result, the virus was detected before an outbreak could occur.
“We were able to mobilize and get out a message quickly and our campus community responded by going to our testing sites which we are especially thankful for given many of them were taking exams and leaving the campus over the holiday weekend,” said Dr. Robert “Chip” Schooley, professor in the Department of Medicine at UC San Diego School of Medicine and a leader of UC San Diego’s Return to Learn program. “This was a great experience from a couple of different perspectives. The science-based decision-making and communication were well received. The test sites and the laboratory managed the surge very well over a holiday weekend.”
Two positive case were identified and the individuals have been in self-isolation.
UC San Diego has been testing sewage for more than a month from two clinics, a research building, and the Revelle dormitories, according to Rob Knight, director of the Center for Microbiome Innovation.
“Wastewater testing will be an important component of COVID-19 tracking projects because it can catch infections that are missed by saliva or nasal swab tests,” said Knight. “In addition, people begin to shed the virus in waste before symptoms develop.”
The campus plans to scale up wastewater testing considerably in the coming months. The Center for Microbiome Innovation at UC San Diego has the advanced technologies to conduct these tests on a large scale. The setup for the project was supported by a team of other researchers in the Knight lab and by UC San Diego Facilities Management, Environmental Health and Safety, and the Office of Strategic Initiatives.
How does the testing work? Wastewater is collected from the samplers every day and brought to Knight’s lab on the School of Medicine campus where viral RNA is extracted, then genes specific to SARS-CoV-2 are amplified by RT-qPCR in the Microbiome Core. The number of PCR cycles gives an indication of how much virus was in the sample. Such analyses have been reported to be sophisticated enough to detect one infected person out of 100,000 who are flushing toilets and taking showers.
It is just one component of Return to Learn program which is guided by three adaptive pillars developed by campus experts: risk mitigation, viral detection and public health interventions. These measures help protect the health and safety of the campus and surrounding community. More information is available at the Return to Learn website.