Volunteers help transport a nursing home resident with coronavirus symptoms to a Barcelona hospital. (Felipe Dana/AP)

BRUSSELS — Up to half of coronavirus-related deaths in Europe are occurring in long-term-care facilities such as nursing homes, the World Health Organization said Thursday, an assessment that suggests public health authorities may have allowed the pandemic to rage among some of their most vulnerable populations as they focused on hospitals and other aspects of their response.

A “deeply concerning picture” is emerging about residents of homes for the elderly, Hans Kluge, the WHO’s top official for Europe, told reporters at a news conference Thursday. According to countries’ estimates, he said, “up to half of those who have died from covid-19 were resident in long-term-care facilities. This is an unimaginable human tragedy.”

Kluge’s warning was focused on Europe, but the United States also has struggled with the pandemic inside homes for the elderly. A Washington Post analysis this week found that nearly 1 in 10 nursing homes in the United States have reported cases of the novel coronavirus, with a death count that has reached the thousands.

Many European countries have banned family visits to nursing homes, an attempt to shelter the residents from the spread of the virus, since it is far more lethal among older people and those with preexisting conditions. But those bans, though well-intentioned, may have deprived the elderly of advocates as conditions swiftly deteriorated.

“This pandemic has shone a spotlight on the overlooked and undervalued corners of our society,” Kluge said.

He and other WHO officials who spoke Thursday said they did not have enough data to say conclusively that people in nursing homes were being transferred to hospitals less often than they should be, or that they were being discharged from hospitals prematurely — fears raised by advocates in Britain and elsewhere. But the WHO officials hinted strongly that those factors might be contributing to the high death rates.

“It is important that the decisions, the very tough decisions that have to be made, are not based on a single criteria like age,” said Manfred Huber, a WHO specialist in long-term care.

Measuring and comparing coronavirus death rates can be difficult, because some nations are testing more suspected coronavirus cases than others are, and each country is using a different accounting method as it records cases and deaths.

Many countries in Europe have essentially ignored coronavirus testing in nursing homes to focus their testing capacity on hospital patients and hospital staffers. In Italy, for instance, a recent national health service report indicated that people dying in nursing homes were overwhelmingly unlikely to have been tested for the virus.

Many countries have not been carefully tracking deaths outside of hospitals, either.

“The challenge is we don’t have very good information for people in care homes,” said Adelina ­Comas-Herrera, a researcher at the London School of Economics.

Comas-Herrera and colleagues reported last week that covid-19 deaths in nursing facilities in Belgium, Canada, France, Ireland and Norway might account for half of all coronavirus deaths in those countries.

She noted that most care homes for the elderly were never designed to serve as acute care hospitals. Many do not even have a nurse on duty.

A first grim glimpse of Europe’s nursing home situation came on March 23, when soldiers sent to disinfect nursing homes in Madrid discovered dozens of elderly residents dead in their beds. Spain’s defense minister pledged that the government would be “unrelenting and forceful” in finding those responsible. As of this week, public prosecutors are investigating some 86 nursing homes throughout Spain for hundreds of deaths. That probe includes 40 facilities in the Madrid region, which has outpaced the rest of the country in deaths.

Spain has not included deaths in nursing homes in its official counts, although authorities say that 10 to 20 percent of residents might be infected.

British Health Secretary Matt Hancock on Wednesday told Parliament that nursing home residents might represent 20 percent of all deaths in Britain. That corresponds to an estimate by the nonprofit National Care Forum, which says the elderly and people with disabilities in residential and nursing homes account for 4,000 of Britain’s coronavirus-related deaths. But some researchers in Britain have put the number as high as 40 percent for deaths in care homes — a staggering number, considering that such facilities house less than 1 percent of the country’s population.

In Belgium, where officials have included suspected cases in their overall death count since early this month, more than half of the 6,450 recorded deaths were in long-term-care facilities, not hospitals. And of those nursing home deaths, 95 percent are “suspected” coronavirus cases, meaning that patients displayed some of the symptoms of covid-19 but were not tested for the virus. 

“We have not had enough testing capacity in the past to confirm all of them in the laboratory,” said Steven van Gucht, the head of viral diseases at Belgium’s public health institute, at a news conference this week. “But that does not mean that those cases are less real.”

Kluge and others say that now is the time to pour resources into group homes for the elderly — to provide more testing of staffers and residents, to supply caregivers with proper protective gowns and visors, and to give them quick training to protect themselves and residents. Some employees have complained that they have been offered little or no equipment. Many facilities are staffed by people with scant medical training or none at all.

Despite the vulnerability of most residents of the facilities, Kluge said, good medical care ought to be able to prevent many deaths.

“Even among very old people who are frail and live with multiple chronic conditions, many have a good chance of recovery if they are well cared for,” he said.

Italian authorities have said some of the worst outbreaks at nursing homes might have been preventable, and they have launched investigations into malpractice at a number of facilities, including one of the largest in the country: the 1,000-bed Pio Albergo Trivulzio in Milan. Italy’s ANSA news service reported that 200 elderly residents had died at that facility.

In France, one of the earliest coronavirus restrictions was an urging by President Emmanuel Macron that people stop visiting elderly relatives in assisted-living centers. But there’s been concern about the psychological toll of that decision.

Nursing home resident Jeanne Pault, 96, lamented in a televised interview this week that she hasn’t been able to eat properly and that she said she is no longer able to converse with her neighbor, much less her family. “Is this a life, at age 96?” Pault said.

Macron responded to her on Twitter. “Madame, your grief overwhelms us all,” he wrote. “For you, for all our seniors in retirement homes or institutions, visits from loved ones are now authorized.”

Visits will be limited to two family members per resident and can happen only after safety measures are in place.

In Germany — where about one-third of the country’s 5,000 deaths have been among residents of care centers, according to data from the Robert Koch Institute — Chancellor Angela Merkel on Thursday said she was particularly “burdened” by what those in nursing and assisted-living facilities “have to endure.”

“It’s cruel that, aside from the staff doing their best, no one can be there for those nearing the end of their lives, their strength ebbing,” she said. “We will not forget these people and the isolation they now have to live.”

Booth reported from London. Christine Spolar in London, Pamela Rolfe in Madrid, James McAuley in Paris, Loveday Morris and William Glucroft in Berlin, Chico Harlan in Rome and Quentin Ariès in Brussels contributed to this report.

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