Delays in COVID-19 contact tracing decreased effectiveness, according to new study from UT researchers

Rylie Lillibridge, Senior news reporter

A new study from UT researchers found that delays in COVID-19 contact tracing undermined the effectiveness of preventing further spread of the virus in Austin.

The study describes contact tracing as a well-established public health strategy put into place to curb the spread of infectious diseases. Through the process of contact tracing, individuals who have interacted with an infected person are notified so they can be aware and follow recommended procedures, said Darlene Bhavnani, an assistant professor in the department of population health at Dell Medical School. 

Researchers examined contact tracing data from UT and the surrounding Austin area. The study found that, on average, it took two days to notify those on the UT campus who had been in contact with someone infected with COVID-19, and five days to notify contacts in the wider Austin area. 

“We found that on campus, those delays … are significantly lower than those in the entire Austin community,” said Xutong Wang, the study’s lead author.

Wang said delays occurred at multiple levels in the contact tracing process, and so the study divided delay data into three segments: testing, result turnaround time and contact tracing. Initial delays in testing arose from people waiting to get tested days after they began exhibiting symptoms. Delays also stemmed from the varying amounts of time it took for labs to process the results of COVID-19 tests. 

As a result, delays in contact tracing meant that those who were exposed to an infected person were not notified until days after their interaction.

“What I think makes more sense to put more effort on is to shorten the test turnaround time,” Wang said. “Those PCR tests are really fast and accurate … but we see at least a day, two days to even two weeks if it’s too busy.”

Bhavnani also said that decreasing test turnaround time is key to shortening delays.

“Expanded lab capacity as well as the development of rapid tests – making them available and accessible to people when necessary – is really going to improve the timing through which we address this test, trace and isolate strategy,” Bhavnani said.

When done effectively, contact tracing is a viable tool to not only prevent the further spread of COVID-19, but also to fight newer viral threats such as monkeypox, said Bhavnani.

“What we need to do is make sure again that we invest in that infrastructure now, so that it’s available and the processes are well understood and that capacity is available, should we need to draw upon it to react to new pandemics,” Bhavnani said. “Although (the study) was based on data from 2020, we can really learn lessons about how to strengthen contact tracing now and in future.”