With the cautious return of thousands of students to Johns Hopkins University this past semester, frequent COVID-19 testing for asymptomatic cases has served as an essential tool for keeping the campus community safe while allowing a limited number of in-person gatherings to take place.
Johns Hopkins University leaders set up a nimble but comprehensive testing operation, with nine sites across its campuses that funnel the tests to a central processing lab on the university's East Baltimore campus. To date, this system has processed more than 200,000 PCR tests, which are using saliva samples to detect COVID-19. All students, faculty, and staff spending time on campus have been required to take the tests each week—with undergraduates required to test as often as three times a week. In such a highly irregular year, the testing became an experience that felt routine.
"There were constant anecdotes of people showing immense appreciation for our testing staff," says Julie Cady-Reh, director of continuous improvement at Johns Hopkins, who has overseen the testing sites. "These displays of gratitude spoke volumes about how meaningful it was for everyone to have the in-person campus experience and emerge from isolation."
Follow the journey of a COVID-19 test at JHU from the campus to the lab below.
As part of the move-in process in late January, Johns Hopkins undergraduates took their first of many PCR tests for COVID-19. About 5,000 students—an estimated 88% of undergrads—returned to Baltimore for the semester, including nearly 1,500 in residences on the Homewood campus.
Shriver Hall—normally host to concerts, guest speakers, and performances—was one of the five sites on the Homewood campus converted to a makeshift testing facility for spring semester. Beyond Homewood, testing sites were opened at the School of Nursing, Carey Business School, Peabody Institute, and the School of Advanced International Studies in Washington, D.C.
The Glass Pavillion was another site on the Homewood campus that was converted into as a COVID-19 testing facility. Undergraduates were required to take three tests a week for most of the semester in response to the pandemic’s winter surge.
A PCR (polymerase chain reaction) test uses molecular amplification to detect the virus’s genetic material. The Johns Hopkins sites distributed an average of about 13,500 tests each week during the semester, with the results typically available within 12 hours of their receipt at the lab, says Cady-Reh.
Once the saliva samples are collected, they’re loaded into a van for delivery to the Stand-Alone Covid Lab in the Wood Basic Science Building in East Baltimore. In a typical day during the spring semester, the lab would receive three to four deliveries from couriers, in addition to tests picked up on the East Baltimore campus, totaling roughly 2,500 samples per day.
Lab staffers Deby Adejuwon and Dalia Ahmed load the heat-inactivated saliva samples into a machine that reformats the samples from collection tubes onto plates. This is the first step in preparing the samples for SARS-CoV-2 testing.
Next up, lab staffer Sierra Johnson-Dendy, with the help of a robot, extracts RNA from the reformatted saliva samples. Isolating RNA will allow for detection of the presence, or absence, of the SARS-CoV-2 virus.
Here, a machine drops PCR reagent mixture onto a plate. The lab performs PCR reactions on every saliva sample to amplify copies of SARS-CoV-2 virus. If the virus is present, a real-time quantitative PCR machine will detect a fluorescent signal indicating a positive test result.
The Stand-Alone Covid Lab staffs about 30 technicians, technologists, administrators, and supervisors. “This team has put in so much energy to start this operation from scratch and process thousands of tests every day and turn them over with quick results,” says Sarah Zaidman, the lab’s administrative coordinator. “Their effort deserves a great deal of recognition, and I hope our Hopkins community appreciates the achievement.”