Maine’s hospital leaders pleaded with the public Thursday to get immunized against COVID-19, saying hospitals around the state are now swelling with unvaccinated patients.

The state also reported 390 new COVID-19 cases Thursday, the highest one-day total since early May, but no new deaths.

Dr. Steven Diaz, chief medical director for MaineGeneral Health, the parent company of MaineGeneral Medical Center in Augusta, said hospitals are “chock full” of COVID patients, and he urged the more than 300,000 eligible Mainers who haven’t received shots to get them.

“We have to do everything we can until we see the pandemic get better,” Diaz said during an unprecedented joint news conference Thursday by the state’s four major health care networks. “We need everyone to please get vaccinated for the health of the community, wear masks inside, do social distancing, and please stay home if you’re ill.”

The hospital leaders did not call for specific actions by the state, such as a return to mandated indoor masking or requiring vaccinations to attend indoor events. At the urging of hospitals, Gov. Janet Mills recently required all health care workers in the state to be vaccinated by Oct. 1 as a condition of employment. Some workers have protested the mandate, although most have been vaccinated.

Dr. Nirav Shah, director of the Maine Center for Disease Control and Prevention, laid out the hospital capacity issue in a tweet Thursday. While the pandemic is not nearly as bad in Maine as in other parts of the country, hospital beds are filling up. About four of every five of those hospitalized are unvaccinated, Shah has said.

“Stats of the day: there are 133 people in the hospital with COVID-19 in Maine right now. Fifty-nine are in the ICU and 27, on ventilators. Of 332 total ICU beds in Maine, 34 are available right now. Yesterday (Wednesday), there were 39 available beds. And on Tuesday, there were 52,” Shah said in a tweet. Maine hospitalizations for COVID peaked at more than 200 in mid-January.

Hospital executives said they are running out of capacity and ability to take care of non-COVID patients.

Dr. Joan Boomsma, chief medical officer at MaineHealth, parent company of Maine Medical Center in Portland, said hospitals “don’t have many more tricks up our sleeve” to add capacity for COVID-19 patients.

“The more COVID-19 patients we take care of in hospitals, the less resources we have to take care of all the other things we need to do,” Boomsma said. Hospitalizations need to stabilize or hospitals may soon have to routinely cancel or postpone elective surgeries, as they did earlier in the pandemic.

Hospital capacity for pediatric patients is also under threat with the rising number of COVID cases, said Dr. James Jarvis, COVID-19 incident commander for Northern Light Health, the parent company of Eastern Maine Medical Center in Bangor and Mercy Hospital in Portland.

“We’ve reached a critical moment in the pandemic, where what Mainers do moving forward will determine what happens next,” Jarvis said.

Jarvis said the network is prepared to set up field hospitals if existing beds run short, but is reluctant to do so because of the staffing challenges that would create.

Boomsma said that while some have criticized the state and health care networks for the vaccination mandate and predicted workers would quit rather than get their shots, allowing some workers to remain unvaccinated leaves them more vulnerable to contracting COVID, which could compromise patient and staff safety.

“We are losing staff because they are infected with COVID,” Boomsma said. “Right now, we are losing staff to the virus, not losing staff to the vaccine.”

Nationally, hospitalizations surged to more than 100,000 in August, nearly double the July total, according to national news reports. Patients have been flooding hospitals in many states, including Florida, Tennessee, Washington state and Iowa.

Maine’s seven-day average of daily new cases jumped to 203.4, compared to 173.1 a week ago and 60.9 a month ago. Since the pandemic began, Maine has recorded 74,699 cases of COVID-19, and 926 deaths.

Despite the high statewide numbers, Cumberland County, the state’s most populous and most highly-vaccinated, reported just two new cases Thursday. Penobscot County recorded the most new cases, with 90, while York County logged 82, followed by Aroostook County with 51.

Cumberland County moved to the moderate infection-rate designation, joining Sagadahoc as the only two counties with moderate virus transmission, according to U.S. CDC guidelines. Cumberland County’s seven-day average for new cases increased in late July and early August, but then plateaued and has been trending downward for the past two weeks even as the statewide daily average continues to climb.

Rebecca Quinn, left and Nathaniel Lombardi, deliver a patient to the Emergency Department at Maine General Hospital in Waterville in December 2020. Staff Photo by Michael G. Seamans

Aroostook, Franklin, Hancock, Piscataquis, Waldo, York and Somerset counties have high virus transmission rates, while all other counties are designated as substantial transmission.

Shah said in a media briefing Tuesday that he had expected high COVID-19 case counts this week because his staff had to work through 1,700 backlogged positive test results to determine how many were new cases. As the delta variant has spread, testing volume has increased dramatically in recent weeks, from 258 tests per 100,000 people two weeks ago to 333 tests per 100,000 currently.

Robert Long, Maine CDC spokesman, said Thursday that the 1,700 tests “have been processed, but we have continued to receive high volumes of positive results since then. We expect the volume of positive test results to remain high, which will in turn mean that the day-to-day change in the number of cumulative cases will also be higher than it has been since spring 2021.”

Maine reported 838,199 people had been fully vaccinated against COVID-19 as of Thursday, 62.3 percent of the state’s 1.3 million population.

Cumberland County leads the state with a 73.6 percent full-vaccination rate, followed by Knox County at 68.2 percent. The two least-vaccinated counties are Somerset and Piscataquis, at 49.9 percent and 52 percent respectively.