UF Health Jacksonville, in Florida's most populous city, has seen an "exponential" rise in the number of COVID-19 patients admitted in recent weeks, Chad Neilsen, director of infection prevention at the hospital, told ABC News.
The previous record for the highest number of daily COVID-19 patients across its two campuses -- 125 -- was set in January; the hospital surpassed that three days ago, Neilsen said, and is currently at 136, with about 40 people in the intensive care unit.
Last week, there were 75 COVID-19 patients in the hospital, 45 the prior week and 20 the week before that, according to Dr. Leon Haley Jr., CEO of UF Health Jacksonville.
"We knew it was most likely due to the delta variant taking a bigger footprint here in the Northeast Florida region because it was so rapid of an increase," Nielsen said. "Everybody in town is suffering the same fate we are."
At the Mayo Clinic's Jacksonville hospital, there has been a "significant" increase in COVID-19 hospitalizations over the past three weeks, "approaching our previous peak numbers," Dr. Ken Thielen, CEO of Mayo Clinic in Florida, said during a COVID-19 press briefing Wednesday with Jacksonville Mayor Lenny Curry and other local health care leaders.
"This represents a five-fold increase in COVID hospitalizations, and follows many weeks when we only had a handful of hospitalized COVID patients," Thielen said.
There are other similarities among the area's hospitals -- the COVID-19 patients they are admitting are largely unvaccinated, and they are younger than what they've previously seen during the pandemic.
Among UF Health Jacksonville's COVID-19 patients, 90% are unvaccinated, and nearly 70% range in age from 40 to 69, Neilsen said. Prior to this surge, 75% of the COVID-19 patients were ages 60 and up, he said.
"We're definitely seeing a shift into a younger demographic of people," he said.
According to Tom VanOsdol, president and CEO of Ascension Florida and Gulf Coast, which operates a hospital in Jacksonville, over 96% of its COVID-19 patients are unvaccinated.
"Our median age of our hospitalized patients is 49 -- it was in the mid-60s in prior waves of this pandemic," VanOsdol said during Wednesday's press briefing. "So it's a younger demographic who are not getting vaccinated that unfortunately are contracting COVID, and these cases are requiring hospitalization for treatment."
At Baptist Health in Jacksonville, the COVID-19 patients are "younger, sicker and getting sicker quicker," Chief Medical Officer Dr. Timothy Groover said during the briefing.
In the past month, 44% of COVID-19 patients at the hospital were in their 40s or younger, and "most were previously healthy," he said.
As the delta variant has quickly become the dominant variant spreading in the United States, Florida is one of four states reporting the highest weekly COVID-19 case rates per capita, with over 200 cases per 100,000 residents, according to the Centers for Disease Control and Prevention.
As of Monday, the seven-day average of new cases went up 107.48% in Duval County, where Jacksonville sits, according to the CDC.
At the same time, fewer than half of the state's residents are fully vaccinated, according to the CDC. Rates are lagging in Duval County, where 41% of residents are fully vaccinated.
"Vaccines are stagnant here in Northeast Florida, and the delta variant is just running rampant amongst the unvaccinated folks," Neilsen said.
Neilson attributes the latest surge in part to delta's rise coinciding with Fourth of July gatherings, but said it's hard to predict where hospitalizations might be heading "because it spreads so quickly."
Hospitals in the region are worried about staff burnout and shortages as the pandemic wears on and unvaccinated staff are exposed in the community and also get sick.
"We're facing a real staffing crisis if this continues," Nielsen said.
The area health care leaders offered a plea for people to get vaccinated if they haven't already, and to continue mask-wearing, social distancing and hand-washing.
Curry also urged residents to get vaccinated -- but stopped short of issuing any restrictions.
"The path to moving beyond the surge and preventing future ones is increasing our percentage of vaccinations," he said during Wednesday's briefing. "The math is clear -- vaccines work. Restrictions to our economy and personal freedoms are not the answer. The answer is getting vaccinated."
"Hospitals are full and busy because of unvaccinated people, so the solution here is to get the vaccine," he added.