Contact tracing: a critical tactic in fight against COVID-19

While contact tracing as a strategy employed in the fight against COVID-19 has made news lately, Dr. John Krueger, Chickasaw Nation Under Secretary of Health, says the idea has its roots in 19th century medicine.

“Contact tracing is really medical detective work,” Dr. Krueger said. “If a person is deemed to be infected with an infection, we contact that person and then ask them to think of anyone they may have come in close contact with. We then reach out to those contacts to offer testing or to establish if they might be affected.”

This strategy can be effective at containing outbreaks and stopping spread of the infection.

Krueger said the first time contact tracing was used was in 1854 when Dr. John Snow in London, England, sought to discover the cause of that era’s dread pandemic – cholera.

“At the time, the theory was that cholera spread through the air,” he said. “Dr. John Snow was a physician in the community and he was able to deduce that it was coming from contaminated water in the Broad Street area, which is modern day SOHO.

“Dr. Snow showed where the affected persons cases had occurred on a map and then conducted interviews to determine where people had obtained their drinking water. He determined the source was the Broad Street Pump and managed to help eradicate further spread by having the handle removed from the pump. Though the source of the infection was actually a contaminated basement septic system that was leaking into the pump’s water supply, the effect of his action was to help stop the spread of the cholera epidemic raging in London at the time.”

Modern day contact tracing involves contacting people by phone or in person to determine those who had close contact with a coronavirus infected patient.

“The vast majority of people coming through our testing center at this time will not test positive; they will test negative,” Krueger said. “Any positive we get back triggers several responses from our health system.”

After checking the condition of the one infected, a trained a member of a Chickasaw Nation team of contact tracers asks permission to conduct a contact tracing interview.

“They will ask about close contacts and try to understand where that person might have traveled to over the last one-to-14 days, who they might have come in contact with and if there were any high risk contacts. After they have the names of those folks, they will start the other part of the investigation, which is to reach out to those other networks and determine if we want to invite those people for testing or just have them isolate at home.”

The idea is to keep them from going out to the broader community and putting others at risk.

“That’s one way you can stop an infection from spreading,” Krueger said.

Patient privacy is uppermost in the investigatory process.

“When we do contact tracing, we don’t tell you who you were exposed to. Sometimes it’s pretty obvious because a family member has told other family members, but we keep your information protected.”

Krueger says it’s important for community members to remain vigilant.

“COVID is still in our community,” he said. “Thankfully, we’ve been able to reduce that spread very significantly through a lot of public health measures put in place.”

He said public health is very different from direct medical care.

“I’m a family doctor by training and most of my care as a family doctor involves taking care of individuals. Public health takes care of populations of people. You have to think a little bit differently when you’re taking care of a large population and you’re trying to think about the wellbeing of hundreds, thousands or even millions of people.

“When we go to the doctor, we think about our own health and not necessarily about how our health condition could affect other people. When you put on your public health hat, you have to ask how the health of everybody affects everyone else.”

Krueger said of the nearly 16,000 total coronavirus tests the Chickasaw Nation has performed to date, a significant number are tribal employees and family members, which helps provide insight into how to stop its spread.

“Seeing our own testing data has been very helpful to us to evaluate our mitigation strategies we have in place. If we need to we can change things to help make our workplace even safer.

“If there are outbreaks, we can rapidly identify them and respond, isolate those individuals, contact-trace them and their close contacts and not only protect our workplace but our communities in which we live and work,” he said.