When a university employee or trainee tests positive, a process begins to identify and contact others who may have been exposed.
When a person tests positive they become a case. Occupational Health interviews every case to re-trace their steps and identify all people who were potentially exposed. Those who are identified as having a high-risk exposure are considered contacts, who are then called to inform them they are considered a contact. Once confirmed, the process of quarantine is initiated. This includes a set of instructions to the individual employee and establishing a health monitoring plan with Occupational Health.
At this time, we are not investigating properly masked interactions because we want to focus our attention on interactions that carry a significant risk of transmission. We have substantial evidence that masks, including cloth masks, work. There are published studies on the CDC website that include an MMWR report from WashU that demonstrated that when actively symptomatic hairdressers were wearing a mask and their customers were wearing a mask while in close proximity for more than 15 minutes, there was NO transmission of disease. However, each situation is reviewed independently and certain dually masked contacts if close enough for long enough may also result in concern regarding an exposure.
These published data have been further corroborated by a marked absence of transmission in our lab or classroom settings on both campuses when this definition of contact was used. When we see evidence of infection in more than one person in a given location where a clear exposure cannot be documented, we do more widespread testing using something called a cluster investigation. These cluster investigations have not uncovered any transmission while masked.