A network of community health clinics in Chicago known for treating LGBTQ patients is doing something unique to help slow the spread of COVID-19: hunting down the virus, one patient at a time.

Howard Brown Health is using a technique known as contact tracing. Dr. John Schneider, an infectious disease specialist and virus detective who is leading the effort, called it a “no-brainer” after Howard Brown got its first confirmed case in March — before cases in Illinois started to explode.

“I was setting up the testing site at 55th Street” — the Hyde Park clinic where Schneider is the medical director — “and when we started getting positives the instinct in me was, ‘Well, I want to know exactly how you got this.’ Then it was, ‘I want to know to make sure the people around you, and the people who surround those people, are not going to get infected. Or if they are infected, they’re going to quarantine and know their status.’ ”

The idea with contract tracing is to start with a sick patient and build a web of people that person has come into contact with to stop a contagion from spreading. Howard Brown’s efforts appear to be unique, because contact tracing is normally something public health departments do. Howard Brown is a network of doctors’ offices embedded in communities throughout the region.

But as COVID-19 rages across the country, public officials, including Illinois Gov. JB Pritkzer, say contact tracing will be key to jump starting the economy and returning to some resemblance of normalcy. Pritzker largely closed schools, businesses and big gatherings about a month ago, and Chicago Mayor Lori Lightfoot added more restrictions.

The shoe-leather work of tracing a virus

Howard Brown has a deep bench of experience when it comes to contact tracing. The storied medical hub has been doing this with syphilis for nearly 20 years, and with HIV for about five years.

Here’s how it works: After a person tests positive for COVID-19, they get a call.

This is what Schneider’s typical script looks like: “Hello. I just wanted to follow up with you about your results. I’m Dr. Schneider. I’m leading some of the efforts to try and understand who might be at risk or who might be susceptible to COVID.”

He asks how they’re feeling and tries to get a sense of what they were doing in the weeks before they tested positive — like whether they went to work or school.

“And then I would start asking about, ‘So who are some of the people that you hung out with or spent time with?’ ” Schneider said. “‘Do you live alone or with other people?’ We probe who is in the household. And then we have other probes. ‘Do you go to the gym and work out with someone regularly? Do you have a card or a drinking group?’ ”

Once they map out that web of contacts, Schneider or someone he works with calls all of those people, asking them the same things. He keeps track of the cases in spreadsheets, giving Howard Brown a detailed look at the spread of the virus.

Schneider said he typically talks to a handful of people who came into contact with someone who tests positive for COVID-19.

“This isn’t just random — hey, I saw someone in passing or I had lunch with somebody once,” Schneider said. “This is like routine and regular contact.”

But sometimes he probes deeper.

Annette Miller was one of 15 people whom Schneider or other people on his team talked to after her son tested positive for COVID-19. Schneider wanted her to get tested, though she hesitated at first after her son described how a medical provider used a nasal swab.

“He thought, ‘Oh my god that test.’ He told me they stuck it all the way down his nose into his throat,” said Miller, 63, who lives in south suburban Dolton. “That feeling that he got was scary. And then I thought, ‘Well, if I’m positive what do I do?’ ”

Annette Miller got over her fear and ended up testing negative. She said she was glad Schneider reached out.

“It wasn’t strange,” she said of his line of questioning. “I embraced it, and I was thankful he took the time out to talk to me.”

She said Schneider also explained what she should do to stay healthy at home (wiping down counter tops and washing her hands for 20 seconds) and when in public (wearing a face mask).

The changing face of COVID-19

Schneider hasn’t yet fully analyzed his spreadsheets to tell the story of how COVID-19 is impacting Howard Brown patients and the people with whom they come into contact. But there’s evidence the community health center is having some impact.

In general, about 65% of the people Schneider and others interview for contact tracing — beyond the original person who is infected — also test positive for COVID-19. The community health center has interviewed about 203 people as part of its contact tracing effort and dozens more are in the pipeline.

And there are lessons Howard Brown is learning about how the virus has upended communities.

At first, Schneider said people who tested positive were those who had money. They traveled and went to fancy parties. Now, Schneider sees more low-wage workers and people of color, such as Uber drivers and baggage handlers.

And like HIV and other sexually-transmitted diseases that Howard Brown has traced for years, he said he senses the stigma some people with COVID-19 feel. He spends a lot of time on the phone, not only tracing the virus, but listening to people’s worries about it.

The conversations can be emotional, like these interviews.

“So we’ve had a couple people, one who’s like, ‘My partner, he’s in the hospital,’ or, ‘My partner died,’ ” Schneider said.

The hardest conversations, he said, are when he starts to get worried about the health of the person on the other line. They pick up the phone, and they can’t complete full sentences.

They’re struggling to breathe. That’s a sign of COVID-19.

Kristen Schorsch covers public health on WBEZ’s government and politics team. Follow her @kschorsch.