In the hardest-hit city in a state already hit hard by coronavirus, Chelsea Police Chief Brian Kyes said officers can’t let their guard down for a moment.

“You never know how many people are carrying the virus,” Kyes told Emily Rooney on WGBH News’ Greater Boston Thursday. “So, what we do is we operate under the general principle that everyone is infected. Everyone.”

In Chelsea, roughly five percent of residents has tested positive for coronavirus — more than one and a half times the rate of infection in the city with the second highest number of known cases per capita, Brockton, which has a little under three percent.

The chief says the department is tracking the location of those infections to help keep his officers safe.

“We don’t get the names of the individuals that have been infected, but we do get the addresses of where they reside,” he explained. “We enter it into our record management system database, so in the event that I or someone else got a call to go to a given address, a hazard flag will pop up on the screen that dispatchers see and they’ll alert the officers that there’s a confirmed isolation … so officers know to take additional precautions.”

Kyes said his department has been lucky when it comes to such precautions. While first responders in some communities are struggling to get a hold of enough personal protective equipment, or P.P.E., Chelsea Police already had some on hand to protect officers against the potent synthetic opioid fentanyl.

“We’ve had what we call Tyvek suits and masks and eye protection and certainly gloves for the longest time,” he said. “We’ve been experiencing problems in Chelsea going back a bit with fentanyl … so we’ve been really learning how to protect ourselves, not knowing what we’re going to encounter when we go into certain homes.”

So far, the mitigation strategies seem to be working. Kyes said, out of 111 total officers, his department has had relatively few official cases of COVID-19.

“No one’s been hospitalized. We’ve had three officers that have tested positive. Two of them have since returned to duty; the third is due to return soon, hopefully early next week,” he said.

These days, it’s safer for both the department and the public if officers don’t have to bring anyone down to the station. But when it comes to cases of domestic violence, Kyes said they have had to make more arrests than usual.

“We really don’t wanna arrest anybody if we don’t have to; we don’t wanna bring anyone into the building. But there are some situations involving intimate partner violence where we’re really left with no choice,” he said. “In Chelsea, we were averaging probably one arrest per day as a result of domestic violence. It turned into one and a half, it turned into two, and now we’re about three arrests per day.”

“Right now, yeah, the numbers are definitely starting to creep up,” he added.

As the pandemic continues and the economic crisis it has caused worsens, Kyes — who is also the president of Massachusetts Major City Chiefs of Police — said he is looking out for spikes in other kinds of crime, too.

“The concern is, with the economic downfall, when people start losing their jobs or getting laid off, when they have to put food on their plate, we may see larcenies increase, shoplifting, perhaps robberies,” he said. “So, we’re bracing for that.”

But so far, Kyes said, crime overall is down.

“Surprisingly it is. I know that’s the case across the Commonwealth. I believe it’s the case across the country,” he said. “Knock on wood, everything else is down.”