In March, Amy Carrier asked one of the two women who provided home care for her mother to stop coming to work.

Her mother, 74, has Alzheimer’s disease and lives with her in Corvallis, Ore. To protect her from the coronavirus, “it was clear that I needed to lock down my house,” said Ms. Carrier, 45, a foundation executive. She allowed one helper, who lived with only an adult daughter, to continue helping her mother bathe, take walks and play puzzles and games.

But the other aide has a household of six, including four teenagers, and was visiting other clients’ homes. “There’s too much chance of exposure,” Ms. Carrier decided. When she explained that to her employee, she said, “she totally understood, and she wanted to be home with her family, too.” At least, because Ms. Carrier hires and pays caregivers legally, the worker is receiving unemployment benefits.

Home Care Partners, a nonprofit agency serving the Washington, D.C., area, said that about 20 percent of its clients, primarily low-income older adults, had suspended their service.

Those aides who are still working face arduous conditions. “They have a higher level of risk, because they’re going into a number of different homes,” said Marla Lahat, the executive director. “They’re often traveling on public transportation, which is severely curtailed here in D.C.”

Acquiring protective equipment, for workers accustomed to hand-washing and gloves but not to masks, proved difficult and expensive. “Hospitals and nursing homes were the priorities; we weren’t,” said Ms. Lahat, who eventually had to buy sanitizer from repurposed distilleries. “It’s been totally disruptive.”

Much of the attention to the toll Covid-19 has taken on older adults has rightly focused on long-term-care facilities. Their residents and employees account for almost 40 percent of the nation’s deaths, according to an updated New York Times analysis.

But far more Americans — nearly six million, by one estimate — rely on paid home care than live in nursing homes and assisted living combined.

Already among the nation’s fastest-growing job categories, personal care and support at home can help older adults age in place — as almost all prefer, surveys repeatedly show — and prevent or delay institutionalization. (This sector, also called personal care, is distinct from home health care, which Medicare covers after hospitalization.)

Such aides — almost 2.3 million of them, according to the research nonprofit P.H.I. — help with everyday nonmedical needs like bathing, dressing and using the toilet; they may prepare meals, do light housekeeping and remind clients to take their medications.

Even when consumers pay $ 22.50 an hour (the national average, according to an annual survey by Genworth), a daily four-hour visit costs far less per month than a residential facility and may allow family caregivers to keep their jobs.

When governors issued shutdown orders across the country this spring, they exempted home care aides as essential workers. “Home care workers can’t socially distance,” said April Verrett, the president of SEIU Local 2015, which represents nearly 400,000 home care aides in California.

But as with so many other parts of the health care system, the pandemic has spotlighted weaknesses and dilemmas.

Even more than nursing home employees, home care workers are poorly paid hourly workers (average wage in 2018: $ 11.52 an hour, according to P.H.I.) and often lack health insurance; half rely on some form of public assistance.

Analyzing federal data, P.H.I. researchers found that, from 2012 to 2017, only one in five home care workers who needed time off for medical or family reasons could take paid leave.

Unsurprisingly, among the for-profit agencies and franchises that employ most home care workers — leaving aside the uncountable private hiring arrangements known as the gray market — turnover nears 70 percent annually, said Vicki Hoak, the executive director of the Home Care Association of America.

“If you don’t have the heart for this, you’ll go work in retail and get paid just as much,” she added.

Now, both workers and clients have more cause for worry.

“Home care workers are probably unknowingly involved in the transmission of Covid-19, especially when they’re not equipped with sufficient P.P.E.,” or personal protective equipment, said Dr. Nathan Stall, a geriatrician and researcher at the University of Toronto and a co-author of a recent article on home care.

Not only do many home care workers serve several clients each week, increasing their exposure, but to piece together a living, they may simultaneously work for several agencies or for nursing homes, or hold outside jobs. One aide at Home Care Partners cleans hotel rooms at night.

Those conditions increase infection risks, and not only for their frail older clients. Almost a third of home care workers, a heavily female work force, are themselves over 55, and most are black or Hispanic, groups that have proved particularly vulnerable to Covid-19.

Protective equipment has proved hard to acquire, however. With hospitals and nursing homes scrambling for supplies, “this was the forgotten sector,” Dr. Stall said.

Even when employers secure it, “how do you get equipment to 400,000 people at 400,000 work sites?” Ms. Verrett said, referring to her membership. “It’s been challenging, to say the least.”

Researchers expect the demand for home care to increase sharply as the population ages. Already, older people preparing for previously postponed elective surgery or recovering from Covid-19 will want or need care at home. These days, moreover, “a lot of people justifiably have fears of entering nursing homes,” Dr. Stall pointed out.

Recruiting aides who won’t decamp for fast-food jobs will require employers to offer higher wages and benefits like paid sick leave, perhaps through full-time positions.

Aides will also need more education — “a huge issue for this work force even before Covid,” said Dr. Madhuri Reddy, a geriatrician with Hebrew SeniorLife in Boston and a co-founder of a tech company that trains home care aides.

With no federal standards for training or licensing aides, home care operates under a hodgepodge of state requirements — or lack thereof. Thirty-five states set no requirements for home care aides, Dr. Reddy said.

“We license people who cut our hair, but not the people who care for our moms?” Ms. Hoak said. Greater professionalization could promote workers’ stature, their income and their ability to care for elderly and disabled clients.

“We don’t get the respect and help that doctors and nurses do, but we’re on the front lines, too,” said Jennifer Washington, who cares for three clients in their 60s in Oakland, Calif. (One is her mother, as California’s Medicaid-supported state program permits.)

Early in the pandemic, Ms. Washington, 43, a home care worker for 20 years and an SEIU Local 215 member, stayed home for a couple of days. Although diabetes and kidney disease increased her own vulnerability to the virus, she worried more about infecting her mother or carrying illness home to her two children.

But her clients, virtually housebound, weren’t exposed to others, she reasoned. And without her assistance with showering, grocery shopping, banking, laundry, meals and simple companionship, they would be alone; their already fragile health might suffer. “They’re kind of like family now,” she said.

So, buying her own masks and gloves, she resumed her $ 14-an-hour visits. “They needed the help,” Ms. Washington said. “They didn’t have any other support. I had to do my job and pray for the best.”

[Like the Science Times page on Facebook. | Sign up for the Science Times newsletter.]