WASHINGTON: More than 1 in 4 cases of possible sexual and physical abuse against nursing home patients apparently went unreported to police, says a government audit that faults Medicare for failing to enforce a federal law requiring immediate notification.

The Health and Human Services inspector general’s office issued an “early alert” Monday on preliminary findings from a large sampling of cases in 33 states. The results were sufficiently alarming that investigators say corrective action is needed now.

“We hope that we can stop this from happening to anybody else,” said Curtis Roy, an audit manager with the inspector general’s office, which investigates fraud, waste and abuse in the health care system. The audit is part of a larger ongoing probe, and additional findings are expected.

With some 1.4 million people living in U.S. nursing homes, quality is an ongoing concern. Despite greater awareness, egregious incidents still occur.

In a statement, Medicare emphasized that nursing home safety is a high priority, but said it will await a complete report before announcing a response. That didn’t impress Sen. Charles Grassley, R-Iowa, who said he will push for Medicare to take immediate action.

“A crime is a crime wherever it takes place,” Grassley said in a statement. “It’s unacceptable for more than one-fourth of potential crimes in nursing homes to apparently go unreported.”

Of the unreported cases, about 4 out of 5 involved alleged or suspected rape or sexual abuse.

The inspector general urged Medicare to systematically scour computerized billing records for tell-tale signs of possible abuse of nursing home residents. Investigators used that approach to find the cases, matching hospital emergency room and nursing home records.

Auditors identified 134 cases in which emergency room records indicated possible sexual or physical abuse, or neglect. The incidents spanned a two-year period from 2015-2016.

Illinois had the largest number of incidents overall, with 17. It was followed by Michigan (13), Texas (9), and California (8).

In 38 of the total cases (28 percent), investigators could find no evidence in hospital records that the incident had been reported to local law enforcement, despite a federal law requiring prompt reporting by nursing homes, as well as similar state and local requirements.

The federal statute has been on the books more than five years, but investigators found that Medicare has not enforced its requirement to report incidents to police and other agencies, or risk fines of up to $300,000.

Nursing home personnel must immediately report incidents that involve a suspected crime, within a two-hour window if there’s serious bodily injury. Otherwise, authorities must be notified within 24 hours.

In one case classified as “reported to law enforcement,” an elderly woman with verbal and mobility limitations was taken to the emergency room after she was allegedly sexually assaulted by a male resident of the same nursing home. The report said two silver-dollar-sized bruises were noted on her right breast.

Nursing home employees did not immediately report the incident to police.

Instead, the following day the nursing home contacted the woman’s family, who called the police, triggering an investigation.