What exactly is contact tracing? and how does it work?

What exactly is ‘contact tracing?’ and how does it work?

Contact tracing is like police detective work. It's pretty straightforward -- find sick people, isolate them and track down everyone they had close contact with.

Dr. Graham Snyder, medical director for infection prevention at the University of Pittsburgh Medical Center, is responsible for contact tracing in the hospitals.

“Who came in contact with this person? Who is contagious for the period of time that they were contagious and did not have the appropriate protection to prevent them from getting sick?” Snyder said.

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In Allegheny County, that gumshoe work began in mid-March when the first two confirmed cases of COVID-19 were reported, both senior citizens living in the same house in Pittsburgh.

The Allegheny County Health Department said there's no known patient zero, and they said multiple sources from out of the country and out of the state introduced the virus to Allegheny County.

Researchers said tracking down who they had contact with is critically important because one person can infect up to three people, and going undetected could lead to an outbreak.

“It can blossom very quickly when you think about the interpersonal connections we have in our day-to-day lives,” Snyder said.

But contact tracing takes manpower. Before the pandemic, the country had about 2,200.

The Centers for Disease Control and Prevention said as many as 300,000 may be needed.

The state is hiring more, and Allegheny County has ramped up as well.

“We do have a plan at the county health department to expand capacity through a small amount of hires and mostly through some volunteer work and using our own staff and some student elective time,” said Dr. Debra Bogen, director of the Allegheny County Health Department.

But will that be enough?

“I have all the confidence in my colleagues in the public sector who lead the contact tracing. They're smart people. The work is hard and they know what they're doing. And yes, it may be the case that they need a lot more personnel power to get the job done, but they know how to do it,” Snyder said.

Both Allegheny County and the state are now using a special cellphone app to provide daily guidance and updates to infected patients and their contacts.

And the state is exploring Bluetooth technology to track who the infected person came into contact with and send an alert to their cellphones. It's voluntary and users would have to opt in.

Still, some experts are skeptical of the process.

The state health department said contact tracing is a proven public health strategy that will ultimately help identify and isolate future outbreaks.

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