The first alarming symptoms were spotted by nursing assistants three weeks ago, and word of the coughing patient sent a ripple of fear through the Detroit nursing home.

The staff had been on alert since a Washington state care home was engulfed by coronavirus, killing at least 35 people in the first major outbreak of Covid-19 in the US.

The virus has since swept from one nursing home to another across the country, leaping between patients and staff. Carers at the Ambassador nursing and rehabilitation center in Detroit, home to about 150 long-term elderly residents, were disturbed as the symptoms spread.

“We didn’t have any protective gear,” a nursing assistant, who did not wish to be publicly identified out of concern over losing her job, told the Guardian. “We had residents with symptoms and nothing to protect ourselves with … The management didn’t seem like they really cared.”

Patients with symptoms were given masks but otherwise left sharing rooms with other elderly residents. A week ago, the nursing assistant tested positive for Covid-19.

“It’s hard because I’m at home and I’m worried about the patients when I should be worried about myself right now … I’m frightened we are going to lose a lot of them,” she said.

With about 1 million elderly residents, long-term care homes have emerged as incubators for Covid-19 outbreaks across the US. It is not a coincidence that the industry is already notorious for creaming profits off while pleading poverty in order to pay low wages to a workforce overwhelmingly of women, usually African American, Hispanic or immigrant. Too often, they are forced to take more than one job to make a living, a factor that has helped spread the virus between care centers.

The Belmont Manor nursing and rehabilitation center in Belmont, Massachusetts. Photograph: Blake Nissen/Boston Globe via Getty Images

In Europe, about half of coronavirus-related deaths in some countries have occurred in care homes. The situation is less clear in the US where the government is not issuing figures and some states, such as Florida, are refusing to identify which nursing homes have confirmed infections. A rough tally of states where figures are available suggests that at least one in five of the country’s 15,000 residential care facilities has been hit by the virus, resulting in about 4,800 deaths. However, health specialists warn that is almost certainly an undercount.

The crisis can be seen in one nursing home after another from Massachusetts and Tennessee to West Virginia. In Iowa, nearly half of Covid-19 deaths have been in care homes. In Texas, nearly 80% of the residents of one San Antonio nursing home were diagnosed with Covid-19 along with eight staff members. The national guard helped evacuate a nursing home outside Nashville after about 100 people contracted the virus and four died.

It’s hard because I’m at home and I’m worried about the patients when I should be worried about myself right now

At the Ambassador home in Detroit, carers worried they could carry the virus home to their families. If they fell sick, they wouldn’t be able to work and most lived close to hand to mouth. Others were concerned that they were the ones carrying Covid-19 into the nursing home and endangering the very people they spent their days caring for.

Through it all, some staff said the management was not taking the threat seriously enough, resulting in at least eight confirmed infections and three deaths to date.

In a complaint against the Ambassador home to Detroit officials, the Service Employees International Union (SEIU) included statements from nursing staff who said they spent weeks making repeated requests for masks, gowns and gloves to protect themselves and the people in their care.

The staff said equipment suddenly appeared hours before Detroit health officials arrived to inspect the home on Wednesday last week.

“Apparently, Ambassador had been hoarding all of this equipment in their storage, but forcing us employees to work without it. This makes me angry! Why would they put our lives at risk, simply because they want to save a few bucks? Even still, we still don’t have enough because we only have two masks and one of the other items,” said one of the nursing assistants in a written submission to city officials.

Several other carers at the home said the management refused to tell them when a patient tested positive for Covid-19 or was suspected of having the virus. Neither, they said, did the company limit exposure to those showing symptoms by putting them into isolation. Some continue to share rooms with other patients.

A healthcare worker attends to Susan Hailey, who has tested positive for coronavirus, at the Life Care Center of Kirkland, Seattle. Photograph: David Ryder/Reuters

“For those people testing positive, Ambassador should have made sure that people who interacted with those patients were warned that they have been exposed, and given some safety protocols. Otherwise, we will unknowingly take this virus to our homes and neighborhoods,” a nursing assistant wrote in a complaint to the city.

The Ambassador is part owned and managed by Villa Healthcare which runs 34 nursing homes across the midwest. In response, the company accused critics of seeking “to impugn our Villa Heroes based on the false allegations of biased parties”, including the union.

It said the first confirmed case of coronavirus at the Ambassador home was not until 6 April and that since then a total of eight residents have tested positive, including four who are now in hospital.

The company denied that staff had been deprived of masks, gowns and other personal protective equipment (PPE), saying that they were available to carers who asked for them. “At no time during this pandemic has Ambassador not had adequate PPE for the use and protection of its staff and residents,” it said.

The company said that none of the deaths of residents since the Covid-19 outbreak had been shown to be attributable to the virus.

But workers at nursing homes across the country are making similar complaints. Dale Ewart, an SEIU official in Florida, said that even care homes trying to do the right thing struggle to find protective equipment.

You have this every man for himself situation where every healthcare company, every hospital, every state, is in this free market system

“You have this every man for himself situation where every healthcare company, every hospital, every state, is in this free market system where scammers and fraudsters and profiteers are charging five, six, seven, eight times the normal cost and nursing homes are always going to be losing out,” he said.

“We’re engaged in a science experiment that’s putting at risk the health of our entire population but first our healthcare workforce, and then the elderly and sick people that they take care of.”

Ewart said that more than 70 staff in the 75 nursing homes where the union has members in Florida are now in quarantine, many without sick pay which he called “a disgrace”.

Mayors in Tennessee and Texas have even blamed care workers for exacerbating the danger by moving between jobs in different nursing homes or going to work despite showing Covid-19 symptoms. But care home staff are often paid minimum wage or close to it, and say they have had little choice but to carry on just to survive.

They also say that many nursing home owners refuse to pay sick leave without a confirmed coronavirus diagnosis. The nursing assistant who spoke to the Guardian said that she works at the Ambassador home and also for a second firm seeing individual patients.

“Nursing staff are living in fear. Some of them are sick but they are pushing it because this is all that they have and they don’t have the means to just to walk away. They’re providing for their families … they don’t have any other options,” she said.

Patients are removed from Magnolia rehabilitation and nursing center in Riverside, California, after 39 tested positive for coronavirus and nursing staff was not showing up to work for their own safety. Photograph: Gina Ferazzi/Los Angeles Times via Getty Images

In other places, staff have stopped coming to work out of concern for their health. More than 80 patients, nearly half of them coronavirus positive, were evacuated from a Riverside, California, nursing home last week after most of the nursing assistants stayed away.

Ewart said falling numbers of carers to look after patients will become a growing problem.

“If we can’t figure out a way to make workers feel like their basic health is being protected … then I would expect that they are going to be people who are going to ask themselves whether they really should be doing this,” he said.

Nursing home owners blame low pay and poor working conditions on the economics of the industry. About 70% of long-term care homes in the US are run for profit. They rely on the Medicaid public health scheme paying for care for the bulk of their income. Nursing home owners complain that the reimbursements, which vary by state, barely cover costs. That, according to the industry trade group, the American Health Care Association, drives down staffing levels and pay, the availability of equipment and the quality of care.

But while the accounts of many nursing homes show slim profit margins, that obscures a widespread practice in the industry of bleeding income into the owners’ pockets through management contracts and other fees.

A Kaiser Health News investigation in 2017 found that nearly three-quarters of nursing homes use financial arrangements intended to suck profits out of the businesses and make it look like costs by paying fees to firms in which their owners have an interest or control. It said the arrangements ranged from renting premises owned by a sister corporation to contracting out basic functions such as management.

The Ambassador home is part-owned by the Olympia Group which is in turn is part-owned by Villa Healthcare. Ambassador said it pays Villa for “consulting services” including providing staff.

Ewart said the industry used the claim of lack of money to weaken regulations on staffing levels in Florida, further endangering patients. The American Health Care Association has pressed the Trump administration to reduce “extremely burdensome” regulation including an Obama-era requirement for increased measures to prevent infections, a recurring problem in nursing homes.

The risk of contracting Covid-19 in care homes is now so great that in California, the public health director for Los Angeles county advised families to take their loved ones out of them. But many residents don’t have anywhere to go or anyone to look after them.

“Most of them, we are the only family that they have,” said the nursing assistant. “They depend on us. They look forward to seeing us. They don’t have access to talk to the people in the outside world. We’re all that they have.”