“There is an ample amount of evidence, and I think you’ve seen it again in long-term care facilities, that it’s the asymptomatic workers who are going into these facilities who are unknowingly, unwittingly potentially passing on the virus,” New Jersey’s Democratic governor, Phil Murphy, said last week. In his state, the number of long-term care facilities with infections ballooned from around 1 in 20 to 1 in 3 in the last two weeks.

One distraught nurse, who works in a South Dakota nursing home, fears she may have been a textbook case of the asymptomatic health worker. Her job is to distribute medication to each and every resident in the home. She may also have distributed the virus, according to a woman whose elderly mother lives in that home and who has seen a social media post from the nurse.

Another problem for public health experts trying to slow the virus in long-term care settings: Not all states are publicly identifying which homes have infections. In addition to the stress on families, that makes it harder to track how the virus is spreading within nursing homes, or how it hopscotches from one to another, for instance via a health care provider who works at several centers.

The intense focus on hospitals is understandable, given their central role. But Nancy Berlinger, an expert on aging at the Hastings Center, a bioethics think tank, said there’s a second simmering health care problem outside the hospital walls that needs to be addressed. “We also have to think of people in the community,” she said.

The federal government has issued several batches of instructions or guidance affecting nursing homes. Some came shortly after the first batch of nursing home deaths in Kirkland, Wash., and some more than a month later.

The Center for Medicare and Medicaid Services, which regulates nursing homes, although much of the inspection work is done by the states, is part of an administration nursing home task force that meets daily, along with the CDC and other health officials.

“CMS is using every tool at our disposal to keep nursing homes free from infection. CMS’s guidance and actions are based upon the most recent CDC recommendations informed by real-time information being gathered from experts on the ground in areas with large numbers of COVID-19 cases,” an agency official said.