The Trump administration has been working to relax regulations governing America’s nursing homes, including rules meant to curb deadly infections among elderly residents.

The main federal regulator overseeing nursing homes proposed the rule changes last summer, before the coronavirus pandemic highlighted the vulnerability of nursing homes to fast-spreading diseases. The push followed a spate of lobbying and campaign contributions by people in the nursing-home industry, according to public records and interviews.

The coronavirus has killed 13 residents at a nursing home in Washington State; dozens more residents and employees there have fallen ill. Seeking to prevent further contagion, some states, including New York, have banned most nonmedical personnel from setting foot inside nursing homes and other long-term care facilities, which nationally have about 2.5 million residents.

Last July, the federal Centers for Medicare and Medicaid Services, or C.M.S., set in motion a plan to weaken rules imposed by the Obama administration that required every nursing home to employ at least one specialist in preventing infections. The proposed rules — which the agency is completing and has the power to enact — eliminate the requirement to have even a part-time infection specialist on staff. Instead, the Trump administration would require that anti-infection specialists spend “sufficient time at the facility.”