United States. An aggressive COVID-19 surveillance and testing effort at Duke University was highly effective in minimizing the spread of the disease among students on campus, according to a case study.
Duke's successful campaign was launched before the start of the semester. Before arriving on campus, all enrolled students were required to quarantine themselves for 14 days, sign a code of conduct that committed to obey mask-wearing and social distancing guidelines, and get tested for COVID.
Once classes began, the university conducted periodic surveillance testing using pooled samples to conserve resources, daily symptom self-monitoring, quarantined contact tracing, and periodic testing for those who had symptoms or had been exposed to someone with COVID-19.
The result: the average prevalence of infection per capita among students was lower than in the surrounding community, and large outbreaks observed on other campuses were avoided. Overall, the combined testing approaches identified 84 cases among students, with 51% among asymptomatic people.
"Our experience at Duke shows that combined risk reduction strategies and surveillance testing can significantly reduce transmissions on college campuses and beyond," said senior author Thomas Denny, a professor of medicine at Duke University School of Medicine and chief operating officer at the Duke Human Vaccines Institute.
Denny said Duke's experience was based on a combination of strategies. In addition to testing and quarantine before students arrived on campus, measures included:
- Creation of a smartphone app for self-monitoring and daily symptom reporting;
- Have students living on campus test themselves twice a week, using kits with pre-labeled containers, swabs, and sample bags; off-campus students assessed at least once a week;
- Strategically locate sites across campus to collect student test samples;
- Grouping of samples in a process called a combined test, with five samples pooled and analyzed for the presence of the virus. Batches that registered positives were divided into individual samples and analyzed separately to identify the source of the positive. The Duke Human Vaccine Institute processed 80,000 samples from August to October.
"At the end of the summer, there were still things we didn't fully understand about SARS-CoV-2 transmission, so there was some uncertainty in the fall semester," said Steve Haase, an associate professor in Duke's departments of Biology and Medicine. "Over the course of the semester, we've learned a lot of things, including that it's possible to limit the spread of the virus and create a safer environment for our students to have that invaluable learning experience on campus."
"Thanks to the collaboration of literally hundreds of dedicated people, along with the high level of engagement of our students, we've had a very positive drop," said co-author Kyle Cavanaugh, vice president of administration at Duke University. "Our dynamic surveillance testing strategy has served as a key component of our experience that has also included high compliance with masking, social distancing, and other key public health behaviors."
Source: Duke University.
