What to know about contact tracing at Purdue

Contact tracing can help contain spread of COVID-19 by identifying those who may be infected and those with which they potentially have had contact, says Dr. Esteban Ramirez, Protect Purdue Health Center chief medical officer.

When it comes to stopping the spread of COVID-19, those who are infected are critical sources of information.

That’s where contact tracing comes into play: the process of identifying and, when necessary, contacting individuals who have been in high risk close contact someone who has tested positive for COVID-19. Dr. Esteban Ramirez, chief medical officer for the Protect Purdue Health Center, says contact tracing will be a critical tool to curb the spread of COVID-19 as students return to campus this fall.

“Once you become infected with COVID-19, it can take two to fourteen days to show symptoms while you’re releasing those virus particles and potentially infecting the people around you at the same time,” Ramirez says. “We know there will be cases on campus, but we can manage the amount of infection we are releasing. That’s what we’re trying to accomplish with contact tracing.”

High risk and low risk exposure 

Ramirez says there are two different types of exposure to COVID-19 — high risk and low risk.

High risk exposure is being within six feet of an infected individual for more than 15 minutes without a mask. Low risk contact is typically described as limited and protected exposure to an infected individual.

“An example of limited exposure is sitting in a classroom, with everyone sitting forward with a mask on and someone in the room happens to test positive,” Ramirez says. “Your exposure to that person was likely pretty limited and protected.”

How contact tracing at Purdue works

Once the Protect Purdue Health Center is notified of a positive case, the first step is contacting that individual directly – usually within a couple of hours, Ramirez says. Students can expect to hear from both a case manager and a contact tracer. 

Purdue currently has 25 case managers and 35 contact tracers.

“Our case managers have one person to take care of, and that person is you,” Ramirez says. “A contact tracer’s responsibility to take care of the people around you.”

The contact tracer will interview the student to determine who they’ve been in contact with and the quality of those interactions to determine who might have had high risk contact and low risk contact. If the student is symptomatic, the contact tracer will try to identify who they’ve been in contact with in the last 48 hours. If the student is asymptomatic, the contact tracer will likely ask who they’ve been in contact with for the last two weeks.

“For asymptomatic individuals, that two week window is really important because we won’t have a way of knowing an exact timeline of when you first got infected and when you started exposing others to the virus,” Ramirez says. 

Then, the contact tracer notifies those individuals who might have had high-risk exposure – without revealing the identity of the person diagnosed with COVID-19.

Those who had low-risk exposure will not be contacted, Ramirez says. 

“Like the example above, if someone in your class tests positive but you were all 6 feet apart and wearing masks, you likely won’t be contacted through contact tracing because that would be a low-risk exposure,” Ramirez says. “These individuals will continue to follow the Protect Purdue Pledge.”

Ramirez says contact tracers at Purdue are also incorporating proximity tracing – which is a data tool pulling from existing Purdue data streams to estimate proximity and duration of an individual’s exposure to someone diagnosed with COVID-19.

Once the contact tracer has collected the data they need, Purdue then turns that information over to the state of Indiana. 

Ramirez emphasized the importance of working closely and quickly with an assigned contact tracer once someone has been notified of their diagnosis. He also pointed out that those who test positive won’t need to notify coworkers or anyone else of their potential exposure and to let contact tracers do the work for them.“Our goal is to get in touch with you as soon we can once we receive notification that you’ve tested positive,” Ramirez says. “We want to intercept any exposure and potential spread if we can.”