In early 2020, Georgia Tech researchers designed a saliva-based polymerase chain reaction (PCR) test and encouraged community members to test weekly to track the health of the campus. Their strategy confirmed 62 percent of the campus’ positive cases in the Fall 2020 semester. The method of surveillance testing — focusing on case clusters and then having patients isolate — reduced positivity rates from 4.1 percent in the beginning of the semester to below 0.5 percent mid-semester.