Contact tracing helps uncover COVID-19's ‘social network’

Published on Monday, June 1, 2020

By: Karen Bascom

Beyond the shelter-in-place orders, personal social distancing measures and clinical trials for treatments and vaccines, University of Mississippi Medical Center medical experts say there is another tool health systems should use to curtail the spread of COVID-19: contact tracing.

The goal of contact tracing is to stop transmission of a disease, said Dr. Mary Currier, UMMC professor of preventive medicine.

“Contact tracing helps us so that a disease outbreak doesn’t blossom,” Currier said.

The Mississippi State Department of Health and other health departments across the country have used contact tracing to track reportable diseases for decades. What counts as reportable varies from state to state, Currier said, but often includes tuberculosis, sexually transmitted infections or vaccine-preventable diseases like measles.

MSDH announced in late March that it would begin contact tracing efforts for COVID-19.

Contact tracing examines the social network of a person infected with a reportable disease. The first task is to identify contacts, or people who spend the most time with that infected person.

In the case of COVID-19, the Centers for Disease Control and Prevention considers close contact as being within 6 feet of an infected person for at least 15 minutes starting from 48 hours before illness onset until the time the patient is isolated.

Usually through a phone call, tracers will ask patients for a list of people in their life who would fit that criteria.

“A tracer will then call the contacts and inform them that they’ve been in contact with someone (with a reportable disease), instruct them on what to do in response and explain the need to quarantine or take whatever actions are required,” said Currier, former MSDH chief health officer.

CDC recommends that people who have been in contact with confirmed COVID-19 patients stay home and social distance for two weeks. They should also monitor themselves for fever, cough or shortness of breath.

Contacts who develop symptoms should self-isolate, notify a physician or health system and get tested, if directed.

Currier said the Medical Center’s COVID-19 mobile testing sites are extremely useful tools. “People can go to a location and be tested for COVID-19 without having to expose themselves to others,” she said.

But once test results come back, the tracers’ work isn’t over.

“If we find that several of the contacts test positive, then tracers start widening their efforts to check with people who may have had less contact with the original case,” she said.

Contact tracing is a specialized skill. To be done effectively, it requires training, supervision and access to social and medical support for patients and contacts.

For example, contact tracers must maintain the confidentiality of the patient and be able to effectively articulate the reason why it’s important to follow health officials’ recommendations.

CDC recommends that public health departments increase their capacity for contact tracing in response to the COVID-19 pandemic. During normal times, reportable diseases have relatively few annual cases, which makes it easier for contact tracers to handle the workload.

But in the case of COVID-19, when there are hundreds of new cases reported daily in Mississippi and tens of thousands nationwide, adequate contact tracing becomes more challenging.

Currier said because of this, the public health strategy needs to include additional forms of mitigation. She said there are three ways public health officials seek to stop disease spread in a community and among contacts: treatments and cures for those infected, vaccinations for those who aren’t and barriers between the two groups.                  

For the first two options, “we have nothing like that yet for COVID-19,” Currier said. Instead, social distancing, quarantine and isolation measures are the most feasible options to mitigate COVID-19 transmission, she said. 

“As the number of new cases goes down, contact tracing becomes a more effective tool,” Currier said.

However, even with the best efforts to track COVID-19 spread, there could still be transmission through people who display no symptoms. Currier advised that maintaining social distancing is critical “not just for your own health, but to protect others.”

“No one wants to be responsible for another person’s death,” she said.

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