Minnesota health officials are sounding the alarm over a worrisome resurgence of COVID-19 infections among residents and health care workers of long-term care facilities.

Since early July, the weekly number of new infections among residents has nearly tripled, with 172 new cases last week. That has been coupled with an increasing number of infections among long-term care employees. Over the past four weeks, 580 employees have tested positive for the new coronavirus, along with 438 residents.

Public health officials are renewing calls for everyone to help stop the spread of COVID-19, which is more likely to find its way into a facility when case numbers in the community are surging.

State regulators are also reviewing their guidance to facilities about family and friend visitation policies, although they say no decisions about changes have been made.

With Minnesota averaging about 700 new COVID-19 cases each day, health officials say the increased spread in communities is having ripple effects in facilities that house some of the most medically vulnerable.

“When there are high levels of the virus circulating, there is only so much we can do from a systems standpoint to prevent workers from being exposed in the community, getting infected and unknowingly bringing it into the facilities where they work,” said Dr. Ruth Lynfield, state epidemiologist and medical director at the Minnesota Department of Health.

Although long-term care cases have taken a turn upward, 257 of the state’s nursing homes and assisted-living facilities have had outbreaks in the past month, representing about 12% of all senior care centers.

COVID-19 is difficult to control because infected people can pass it on to others without feeling sick.

Although some people do not develop any symptoms, those that do can be infectious before they feel any warning signs that they might pose a danger to others.

“What we are seeing with community spread should be a concern for everyone with a loved one in long-term care, everyone with a child who wants to be able to go back to in-person learning at school, and really everyone in Minnesota who wants to move ahead,” said Michelle Larson, the health regulations division director at the Health Department.

In the absence of a vaccine, health officials say the only way to control the virus is for everyone to wear a mask in public places, practice hand hygiene, social distance and avoid large gatherings.

Each new infection can start a chain of illness that can eventually reach those who are more likely to develop COVID-19 complications, including the elderly or those with compromised immune symptoms.

The pandemic took hold in the state’s long-term care facilities early and spread rapidly.

It started with four cases in the third week of March and two months later reached a peak with more than 1,000 cases in the third week of May.

New cases decreased after new protocols were introduced to supply facilities with personal protective equipment and testing was expanded.

Altogether, there have been nearly 7,900 cases among long-term care residents and workers, which account for 13% of the 59,185 confirmed cases in the state.

But 76% of the state’s 1,640 coronavirus-related deaths have been residents of nursing homes and assisted-living facilities.

Of the four additional deaths announced Friday, one was a long-term care resident.

A total of 556 new confirmed COVID-19 cases were reported Friday on a volume of nearly 16,000 tests.

Hospitalizations had a net one-day loss of 19, with 300 patients needing hospital-level care, including 155 in intensive care.

The initial outbreaks led to restrictions on visits by family members and friends.

Many of Minnesota’s 2,000 senior care communities had become like small fortresses, with “No Visitor” signs blanketing their entrances.

Citing encouraging trends, the state began to relax the lockdown restrictions in mid-June, by allowing people to visit outside the homes, provided they wear masks and maintain social distancing. Then last month, many long-term facilities began allowing indoor visits by designated family members and outside caregivers.

State regulators say they are not ready to pull back on these visits, mostly because they help ease the social isolation that can lead to behavioral and health problems.

They are considering alterations that would set visitation policies based on the infection rates in the community, similar to the decentralized approach that was developed for schools.

“It would be very facility-driven, based on what is happening in their community and what is happening in their own facility,” Larson said.

The director of a statewide advocacy group for long-term care residents and their families strongly cautioned against any move to tighten visitor restrictions as “exactly the wrong thing to do.”

“The rising spread [of COVID-19] is not about family caregivers getting access,” said Kristine Sundberg, executive director of Elder Voice Family Advocates. “It’s about keeping COVID out of these places, and you have to start with protective equipment and testing.”

She added, “The need for these families to get in to these facilities to monitor care has never been greater.”

Deborah Veit, executive director of Oak Meadows Senior Living, a senior community in Oakdale with 130 residents, said the resurgence of COVID-19 cases, particularly among workers, is a “huge concern,” and is among the reasons why Oak Meadows has maintained boundaries around family visits.

She estimates that Oak Meadows is getting up to 15 requests a day from family members seeking to visit their loved ones at the community.

“Every day we’re thinking, ‘OK, should we step back a little bit? Do we need to pull in the reins?’ ” Veit said. “It has to be acknowledged and looked at every single day.”

Health Department guidelines say that every one who enters a facility, including workers, should be screened for symptoms and receive a body temperature check.

Dustin Lee, chief executive of Prairie Senior Cottages, which operates seven assisted-living and memory care homes statewide, is holding personal meetings with each of his 180 staff members.

In addition to talking about COVID-19 risks and spread, he is also trying to identify caregivers in his facilities who are not taking the virus seriously.

“The one-on-one conversations with our staff take a lot of time, but I can’t think of any other way to address this. There are no shortcuts to getting in front of this deadly virus,” Lee said.

Lee estimates that about 85% of the staff recognizes the severity of the illness.

The remainder tend to be younger, single workers who require further education.

So far, Prairie Senior Cottages has not had a single case of COVID-19 among its residents or staff.

“The reason why COVID spreads is because of human behavior,” Lee added. “We can stop the spread by wearing masks and by social distancing and by almost obsessive hygiene. We can control the spread of this by staying vigilant and really doing a lot of really simple but essential things.”