Once every week, students living on Stanford’s campus swab their own noses to test for coronavirus. If they test positive, they’re tested again. Faculty and staff are encouraged to get tested at the same rate. 

Over 40,000 tests later, Stanford has a mere 0.1% positivity rate: 33 student cases and 7 among faculty, staff or postdocs since June 29. 

Stanford Health Care — a separate but next-door entity from Stanford University — is not included in that regimen. Employees who are symptomatic or have been exposed to the virus are required to get tested by the hospital system’s clinic, but are ineligible for Stanford’s weekly surveillance testing. 

The separation means that the cumulative 474 positive tests among the 14,000 employees of Stanford Health Care from the start of the pandemic to Wednesday at noon are not reflected in the University’s COVID-19 dashboards. Seventy-six of those cases were identified on or after Aug. 31, a week before the University’s surveillance testing for students began. Over the last week, the average positive rate among Stanford Health Care employees was 1.5%; Santa Clara County’s was 1.6%.

[View more data on positive tests among Stanford Health Care employees at The Daily’s COVID-19 dashboard]

Stanford Health Care has conducted a total of 4,212 tests on employees since June 22; Stanford has administered 40,264 since June 29.  

In April, Stanford Health Care tested over 12,000 asymptomatic employees over the course of two weeks, and found only 0.3% tested positive, according to spokesperson Julie Greicius. In recent weeks, testing of asymptomatic employees has yielded positivity rates “well under” 0.25%, according to Dr. Bryan Bohman, Stanford Health Care’s Associate Chief Medical Officer of Workforce Health and Wellness.

“The testing needs and goals are very different for a university campus vs. a health system,” Bohman wrote in an email to The Daily. “Our health system employees don’t have congregate living arrangements; also our university students/employees don’t have the same PPE policies and procedures as we do in a health system.”

Stanford Health Care employees are, however, permitted to enter outdoor spaces in the campus zones during their workday, prompting questions for third-year resident physician J. Bradley Segal.

“As individuals who are on campus almost every single day of the week, I just can’t understand why we wouldn’t also be tested as part of that ongoing disease surveillance effort,” he said.

Stanford Health Care employees who are asymptomatic and exposed to the virus are required to be tested twice, once two to five days after exposure and again 14 days after. Those without symptoms or exposure can seek out a test at most once every two weeks. 

John Swartzberg, clinical professor emeritus of infectious diseases and vaccinology at UC Berkeley, agreed with the testing systems Stanford University and Stanford Health Care has in place.

“For Stanford, testing the students once a week is very reasonable,” he said. “The more tests we can do, the better.”

Stanford justifies its mandatory weekly testing of students as “largely due to the congregate and high-density living situations for students in university-provided housing.” All students currently living on campus are housed in the Escondido Village Graduate Residences.

In reference to moving testing of Stanford Health Care employees to a weekly cadence, Swartzberg said, “While I would never speak against testing, I don’t know that that’s a valuable use of that resource.”

George Rutherford, an epidemiology professor at UC San Francisco, agreed. Stanford is not over-testing “more than anybody else is,” he said. 

“It strikes me as prudent to not over test, if there really is not a lot of risk of transmission,” Rutherford said, citing the April study that found a 0.3% positivity rate among asymptomatic employees. 

Stanford Health Care maintains it has the ability to conduct as many tests as it sees fit.  

“Any decision about asymptomatic testing depends on a number of factors, including community COVID-19 prevalence, the accuracy of the tests that are available, and also convenience, speed, and costs of testing,” Bohman wrote. “We do have adequate testing capacity to test as many employees and patients as we think is necessary to maintain a very safe care environment.”

This article has been updated to omit reference to Vaden Health Center, as not all student testing occurs there. It has also been corrected to reflect that the number of tests conducted on Stanford Health Care employees since June 22 is 4,212, not 4,264. The Daily regrets this error.

Contact Julia Ingram at jmingram ‘at’ stanford.edu.