When someone in Hamilton answers the phone and hears "We've gotten your results and you've tested positive for COVID-19," they are likely hearing Tracy Sauder's voice.

She is usually met with dead air.

"There's a pause and I respect that pause … we leave them that few seconds to register that information," she told CBC News.

Sauder is one of roughly 189 people working in Hamilton's COVID-19 Response Team, a squad of public health workers in an endless race against time to reach the virus before it infects a new person.

"I've become a detective," Sauder said.

They are a critical part of Hamilton's fight against the novel coronavirus, tracking patients and their contacts, delivering difficult news, but also providing public health officials key information about how and where the virus is spreading in the community.

The staff at the operation centre work two shifts every day, one from roughly 8:30 a.m. to 4:30 p.m. and another from 1 p.m. to 9 p.m. In past weeks, many workers stayed later.

About 10 nurses operate a hotline to redirect callers. Just as many screen patients and their symptoms to determine the next move. Other staff members are data analysts, administrators or people who check in on those in self-isolation.

Sauder is a case manager. When she talks to someone, the person on the other end either has COVID-19 or came in contact with an infected person. She is also tasked with finding out what someone's life was like 24 hours before they started experiencing symptoms, a time when they could spread the virus to others. It's usually a 45 minute conversation.

"You get a little smidget of information and start down the trail and start trying to figure out who the next person to call for information is," Sauder said.

The contact tracers also end up reviewing someone's work history, cold-calling places the person went. Or they search on Canada 411 and scour social media.

The bearer of bad news

The team then tracks down where the person went, who else was there and exactly how close they were to each other, whether it be a dinner party with friends or a few minutes in a waiting room.

Anyone who is six feet away is called a "casual contact" and they are likely safe. Anyone closer is a "close contact" and they have a higher chance of being infected. But both get a phone call.

"You make a cold call to someone you've never met before and tell them their life is going to change now for the next 14 days because they have to be in self-isolation," Sauder said.

"The first question out of their mouth is always 'who is it' and you can't tell them that, you can only tell them the date … and then they tell you their life story."

Being the bearer of bad news isn't easy.

"There's some vicarious emotional impact for us," Sauder said.

"We're really standing behind one another strongly and if we have an especially emotional call, we get off the phone and debrief right away."

A graph by the city of Hamilton shows there are 39 confirmed cases of COVID-19 in Hamilton as of Wednesday afternoon. Meanwhile, more than 900 have influenza. (Submitted by the city of Hamilton)

Sometimes the calls are too much to bear and other times workers struggle to get off the phone.

"We legitimately have to remind people, please take your break, please grab a bite to eat, walk around the office, get a beverage," Connie DeBenedet, the manager of the city's infectious diseases program, said.

"These people really are so passionate."

In some instances, they learn about a case late Friday or on the weekend, involving a person with few to no contacts, leading to a dead end.

That's when they reach out to Dr. Elizabeth Richardson and Dr. Bart Harvey, Hamilton's medical and associate medical officers of health.

"Sometimes we'll reach out to our colleagues across the province and say 'So we just got this case and this situation and I don't know if we've ever seen this,'" Harvey told CBC News.

"Ideally we're trying to get through it as quickly as possible … it's usually pretty straightforward but every now and then it's a sleuthing puzzle."

Response team likely won't grow

DeBenedet said the team likely won't grow much more, despite growing rapidly in the last four weeks.

Sauder knows there's still work to be done, but also thinks that is a sign of relief.

"I was problem-solving every single case and imagining cases when I went to sleep," she said.

"I can go home on time now and leave work at work and I couldn't do that the first couple weeks."

There are 39 positive cases of the novel coronavirus in Hamilton as of Wednesday afternoon.

DeBenedet stressed that anyone who is tested must go into isolation until they get a negative result. They should also remain in isolation for 14 days from when they travelled internationally or were in contact with an infected person.