Field hospitals built to handle a surge of COVID-19 patients in Massachusetts are starting to wind down operations as the rate of new daily cases declines in the state.

Dr. Eric Dickson, the CEO of UMass Memorial Health Care, which oversees the field hospital at the DCU Center in Worcester, said there were still some patients there as of Wednesday morning, but anticpated that it would be empty by later in the day.

At its peak on around May 1, Dickson said, the DCU Center had 100 COVID-positive patients.

"If not for having the DCU set up as an entire area [of] negative pressure — and that's what's required to take care of patients with coronavirus — we would have been overwhelmed at our hospitals," he said.

Dickson said that five field hospitals were set up in the state, but only two — Boston Hope at the Boston Convention and Exhibition Center, and the field hospital at the DCU Center — were put into play.

Partners HealthCare, which manages Boston Hope, did not respond to a request for comment for this story. But Dickson said there's been a decrease in patients there, and that he thinks it will follow DCU's suit within the next couple of weeks.

In the worst-case scenario, Dickson said, the state would have needed all five field hospitals, and in the best case, it wouldn't have needed any. What it ended up with was somewhere in between.

But the DCU Center isn't closing as much as it's getting sidelined for the time being, he said.

"The DCU will remain completely set up, ready to open, should there be a second surge, should there be a need for it," he said. "And it won't take us the eight days, amazingly, that we got it set up that quickly. It will take us less than 24 hours to go operational again if needed."

Dickson cautioned that the virus isn't going away anytime soon. He said that if another surge were to happen, it would be on top of a baseline starting point that is much harder to work with.

As the state starts to slowly reopen, Dickson said there will likely be an increased spread of the infection. The hope is that it will be slow and small enough to maintain.

"I think it's the right time," he said. "I think we clearly have seen a reduction in the number of cases and number of hospitalizations. So we have some breathing room now. But it's not back to normal, it's nowehere close to that. Because we would be not only back to where we were on May 1, but worse than that, 'cause again, we haven't cleared out these cases that we have today."