For 12 consecutive days, Minnesota has seen more than 1,000 new COVID-19 cases, with 1,632 new cases announced Monday.

With the pool of infections getting bigger every week, health experts are concerned that colder weather, as well as the holiday season, could further accelerate case growth.

"We are now at a crossroads of pandemic fatigue and pandemic anger," said Michael Osterholm, an epidemiologist and director of the Center for Infectious Disease Research and Policy at the University of Minnesota. "Basically the public has said they are done with the virus. Unfortunately, this virus isn't done with us."

Osterholm said the significant case growth in 41 states over the past two weeks, as well as a resurgence in Europe, is caused by people not following public health guidelines, such as mask-wearing, social distancing and avoiding large crowds.

"I think the next 12 weeks in particular will be the darkest days of the pandemic," he said.

While most people experience no or mild symptoms from COVID-19, they still can infect others, setting off a transmission chain that could ultimately sicken those whose medical conditions make them more susceptible to serious illness or death.

"For the first time we are seeing faster growth in cases than testing," state Health Commissioner Jan Malcolm said.

With 124,439 known cases since the first infection was detected in Minnesota in early March, hospitalizations and fatalities are rising along with case growth.

There have been 2,239 COVID-19 deaths, including five more announced Monday. About 70% of all fatalities have been among long-term care residents, and all but one of the new deaths have been nursing home or assisted-living residents.

Over the past week, 458 people were admitted to hospitals. Of those, 80 required intensive care.

People with underlying health conditions, including heart disease, chronic obstructive pulmonary disease, kidney failure, obesity and diabetes, are most likely to be affected by COVID-19 complications.

State infectious disease director Kris Ehresmann said hospitals in the metro area have been more than 80% full for most of October. The percentage of intensive care beds in use by COVID-19 patients is up from 9% in September to 13% this month.

"It is typical for hospitals to be full, but obviously we want to monitor that," she said.

About 22,000 test results were reported to the Minnesota Department of Health on Sunday, a 30% drop. Over the past five days, average testing volume has been 29,500.

While recent trends show that testing increased 7.8% from the previous week, case growth was 9.6%, Malcolm said.

The percentage of tests that come back positive is also increasing, with 5.8% of tests finding COVID-19 infection, an increase from 4.9% the week earlier.

"This testing positivity rate over 5% is a red flag for us," Malcolm said. "The rate of viral presence is still high and growing."

Since the pandemic began, 88%, or 109,963, of those sickened are considered to no longer be infectious.

Community transmission, rather than isolated outbreaks, is driving case growth, Malcolm said.

"What seems to have changed more recently is the decisions that we are making to kind of let down our guard in more private settings," she said. "We are not seeing as many problems in the public settings."

With Thanksgiving five weeks away and Christmas coming a month later, Malcolm urged the public to keep gatherings small.

"This is not a typical year, and our strongest advice to people is to take many more precautions about holiday gatherings," Malcolm said.

Osterholm said that holiday risk could be reduced if families acted like many sports teams, quarantining themselves for 14 days before the holiday get-together.

"It is really dangerous for many families to come together during the holiday," he said. "I've seen far too many situations where a young adult brings home the virus," infecting the parents or grandparents.

Osterholm said that health officials need to retool their messages to the public in order to have them become more effective.

"I think they do in the sense that we have to be really explicit in what this means," he said. "We tend to not want to upset or alienate the public. That means we sacrifice being truthful."

Malcolm said it might be helpful for the state to partner with community organizations to encourage adherence to safety guidelines.

"We've been really trying to drive home the same basic message all along," she said. "It does seem to us that some people might be tuning out some of the messages."

Nationwide, the country saw a surge in cases at the beginning of the pandemic, high levels of infections in the summer and now a resurgence in the fall.

To Osterholm, we are still in the first wave of the disease. Technically, he said, a second wave wouldn't come until the first wave subsides almost completely.

"True waves with an infectious disease are in a sense like the seasons themselves," he said, pointing to the 2009 flu pandemic, in which the first wave in April and May ended without human intervention, only to have the pandemic re-emerge in the fall.

"We really don't understand why that happens," he said.

The case growth we are seeing now is the result of people not taking precautions, he said.

"It keeps burning and burning," Osterholm said. "It is a situation where when the public basically limits contact and we get physical distancing to work, that is when you slow down transmission."