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— Clinical

Test Driven

Before you can treat COVID-19 — or understand the scope of the health threat — you need to know in whom and where the virus lurks

In the early days of the pandemic, scientists and physicians struggled just to understand the scope and scale of the looming public health threat. Who was infected? How many? Where?

Answers were scarce, in large part because testing was equally so, and without comprehensive testing data, no one really knew what was happening.

In late-February, the Food and Drug Administration (FDA) debuted guidance permitting university-based hospital labs to develop SARS-CoV-2 diagnostic tests. Steve Gonias, MD, PhD, chief of pathology services for UC San Diego Health and chair of the Department of Pathology at UC San Diego School of Medicine, headed a committee to coordinate lab efforts among the five UC medical centers and later represented those labs in UC’s broader response to the pandemic.

In late March, UC San Diego Health announced it was partnering with five leading in vitro diagnostics manufacturers — Thermo Fischer Scientific, Roche Diagnostics, GenMark Diagnostics, Abbott Diagnostics and Luminex Corporation (the last being a test developed at UC San Diego) — to expand testing capacity. Each manufacturer produced its own testing platform, but none alone could meet UC San Diego’s overall need. In combination, however, they might help weather the coming storm.

Open exam: UC San Diego students are able to conduct self-tests for detecting SARS-CoV-2, following a few simple, illustrated steps.

Ordinarily, said David Pride, MD, PhD, an infectious disease specialist and director of microbiology at the Center for Advanced Laboratory Medicine (CALM) at UC San Diego Health, a single testing platform would be used for sake of consistency.

“We took a diversified approach to meet our patient care needs. Having different platforms means we are able to maintain testing supply, even when one or more manufacturers can’t meet our testing needs,” Pride said.

The goal was to boost testing capacity to 1,000 to 1,500 tests per day within two to three weeks, up from the then-current rate of just a couple dozen tests per day. That ambition was quickly reached. Within six months, CALM had expanded capacity to 6,000 COVID-19 tests daily. Typical turnaround time was reduced to approximately 16 hours.

“In my 17 years as chair of the Department of Pathology, this is perhaps the best example of our pathology lab directors and hospital leaders coming together to accept a challenge on behalf of our entire state and country,” said Gonias. “We succeeded at a high level.”

In April 2020, UC San Diego Health launched serological testing, which looks for the presence of antibodies to the novel coronavirus, evidence that a person has been previously infected, even if they never experienced tell-tale symptoms.

“This is part of the next wave of testing,” said Ronald W. McLawhon, MD, PhD, director of CALM and UC San Diego Clinical Laboratories and chief of the Division of Laboratory and Genomic Medicine. “It’s intended to answer those growing questions about who has been infected and who might still be vulnerable to exposure.”

“We took a diversified approach to meet our patient care needs. Having different platforms means we are able to maintain testing supply…”

David Pride, MD, PhD

Serological testing was conducted most often in the early months of the pandemic, but less so as vaccination rates increased, with more and more persons possessing antibodies through inoculation.

In May, UC San Diego went live with its own university-based, FDA-approved COVID-19 diagnostic test.

Other UC labs soon followed. On August 31, 2021, UC San Diego Health crossed a milestone, performing its millionth COVID-19 test.

to Learn

A major component to bringing students back to campus and the resumption of in-person instruction was widespread testing, which began with the official launch of the Return to Learn (RTL) program in May 2020.

Testing formally began with on-campus locations providing self-administered, nasal swab-based COVID-19 tests to the approximately 5,000 undergraduate and graduate students who continued to reside on campus, with plans to expand to monthly testing of all 65,000 students, staff and faculty in the fall.

“Asymptomatic testing is important because most of the transmission of the virus is done by people who aren’t having symptoms”

Robert Schooley, MD

“Asymptomatic testing is important because most of the transmission of the virus is done by people who aren’t having symptoms,” said Robert Schooley, MD, an infectious disease specialist, professor of medicine and one of RTL’s leaders.

“People who do develop symptoms begin to shed virus from the nasopharynx two or three days before those symptoms appear. These individuals feel fine, yet they are shedding larger amounts of the virus at this stage of the illness than after they become ill. This happens because in the beginning stages, the virus turns off the ‘first response’ elements of the immune system. These responses are responsible for the flu-like symptoms we experience in most viral infections. The virus grows unimpeded and leaves us unaware of our infection. This phase of the illness is known as the “pre-symptomatic phase.”

In October 2020, more than 6,000 students moved into dorms, which had been reorganized to incorporate pandemic mitigation measures, such as single-resident rooms. Those numbers expanded with the winter semester and continued to grow, along with the percentage of courses offered in-person.

Throughout, testing has continued unabated, fueled by easy-to-use vending machines that dispense COVID-19 tests, the involvement of the Expedited COVID IdenTification Environment (EXCITE) lab (which in tandem with CALM doubled testing capacity) and other monitoring measures. The tests are free and available to students, staff and faculty.

On September 20, the 2021 Fall Quarter began, with total enrollment exceeding 40,000 students. Of the nearly 12,000 undergraduate students who had moved into campus housing, only 13 tested positive for COVID-19.


With time, the ability and capacity of UC San Diego clinicians and scientists to test for COVID-19 expanded dramatically. It was offered in drive-through settings, to persons requiring testing before travel and to other public institutions, such as local schools via the EXCITE lab, who needed an early detection system in order to reopen their own classrooms.