Brent Walters, MD, critical care and emergency medicine physician, in a patient room during a Park Nicollet Methodist Hospital COVID-19 Emergency Room tour last month. [Credit: DAVID JOLES, Star Tribune] (The Minnesota Star Tribune)

The number of Minnesotans receiving intensive hospital care for COVID-19 jumped by nine Friday, the largest single-day increase in more than a month.

But state health officials were more concerned about what the overall testing and ICU numbers show after the July 4th holiday weekend, when more people travel and socialize in large groups, potentially exposing themselves to the novel coronavirus.

Dr. John Hick, an emergency-medicine doctor advising the state on COVID-19, said one of the first signs of increased transmission will be accelerating case counts.

"I would be surprised if we are not seeing a significant uptick here in the next couple weeks," Hick said Friday of the Minnesota numbers. "If we don't, it's going to be a blessing. But we'll see what happens. ...

"Generally speaking, we're going to look for an increase in cases, then an increase in hospitalizations and ICU use, and then the deaths will increase later."

Minnesota's seven-day average for COVID-19 case counts has been steadily climbing since mid-June, according to Minnesota Department of Health data. While the number of patients in ICU also rose Friday, the number hospitalized with the virus who were not in ICU declined.

The rate of death from the virus remains largely flat.

The uptick in COVID-19 case counts in Minnesota and the number of patients in ICU beds comes as government leaders across the country take steps to prevent new transmissions and curb a national spike in lab-confirmed cases, which have been surpassing 50,000 a day in the U.S. for the first time since the outbreak began.

This week Texas Gov. Greg Abbott mandated the wearing of masks in most counties in his state, which is adding more cases per day than most other states. And New York City Mayor Bill de Blasio indefinitely delayed the reopening of indoor dining in restaurants and bars in his city as a precautionary step after seeing the sharp rise in cases elsewhere.

"This is a very patient virus," Hick said. "Once you lose control of this in a community, in a state, it is too late. Putting this thing back in a box is not just as easy as saying, 'Oh, well now I'll start wearing a mask.' We've got to be proactive."

Minnesota added 423 new lab-confirmed cases of COVID-19 to its statewide tally Friday and eight additional deaths caused by the viral respiratory condition.

The state has reported 37,624 confirmed cases of the illness since March 5. Of those, roughly 32,000 people have since been released from self-isolation.

The slow increase in the average number of new daily diagnoses since mid-June is driven by people in their 20s and teens contracting the virus, state data show.

The nine additional COVID-19 cases that required intensive care as of Friday represent the largest single-day increase in ICU care since May 29. All told, 132 people are receiving ICU care for COVID-19 in Minnesota, Health Department data showed. The number of people in regular hospital beds for COVID-19 care dropped by 13, to 138.

The rate of death from COVID-19 has remained much unchanged in Minnesota. Seven of the eight people whose deaths were recorded Friday lived in long-term care facilities, and all were at least 60 years old.

Joe Carlson • 612-673-4779