WASHINGTON — Before COVID-19 killed thousands of nursing home residents, about 4 in 10 homes inspected were cited for infection control problems, according to a government watchdog report Wednesday that finds a “persistent” pattern of lapses.

In light of the pandemic, seemingly minor cutting of corners such as an employee caring for residents while battling a cold has taken on new significance.

“Warning signs were ignored and nursing homes were unprepared to face a pandemic,” said Sen. Ron Wyden of Oregon, the top Democrat on a committee that oversees Medicare and Medicaid. “There need to be big changes in the way nursing homes care for seniors.”

The report from the Government Accountability Office found that state inspectors who help enforce federal nursing home standards classified the overwhelming majority of violations as not severe, generally meaning there was no actual harm to residents. The federal Centers for Medicare and Medicare Services carried out enforcement actions for 1% of violations classified as not severe from 2013-2017, the report said.

Nursing homes ended up bearing the brunt of the coronavirus outbreak. About 1.4 million people live in some 15,500 facilities in the United States. Most of those people were already at higher risk due to age and medical history, and they also shared dining rooms, recreation areas, bathrooms and sleeping quarters.

An ongoing tally by The Associated Press has found over 34,000 coronavirus-related deaths at nursing homes and other long-term care facilities, more than one-third of all COVID-19 deaths in the country.

The GAO report found that about 40% of the nursing homes inspected in each of the past two years were cited for problems with infection control and prevention.

Looking deeper into federal data for 2013-2017, investigators found a recurring pattern of problems. Data for that five-year period showed that 82% of nursing homes inspected, or 13,299, had at least one deficiency related to infection control and prevention. About half of the facilities had an infection-related deficiency in multiple consecutive years.