ABOSAMSO, Ghana — Hayford Amponsam was making his daily rounds in this small town in south-central Ghana when he came across an infant who was dangerously ill. She had bloody diarrhea and had been coughing up thick mucus for days. Her mother had only sought treatment from a nearby traditional healer.

As a member of Ghana’s inaugural class of 20,000 community health workers, or CHWs, Amponsam, who hails from the area, had been trained for such a situation. He suggested they set off for the nearest health clinic immediately. He carried the girl the 10 minutes it took to cover the one-kilometer journey by foot.

“We were told,” he said, that “if she hadn’t reached there at that time, we don’t know what would have happened.” The infant was treated and, after several days, released. Every afternoon for the next week, Amponsam dropped by the house to monitor the girl’s improvement, offering suggestions on how to keep her healthy.

“The mother was joyous,” he said. The following Sunday she stood up in the church they both attend, telling the congregation that Amponsam had saved her daughter’s life.

In a country where about 45 percent of the 28 million people live in rural communities miles from health clinics, with no reliable form of transportation, the government began deploying thousands of CHWs in 2016 to bridge the gap in access to health services. Trained in basic health care, the CHWs assist in emergencies and also — as important — take steps to prevent those emergencies from happening.

“We believe,” said Nathaniel Ebo Nsarko, who heads Ghana’s chapter of the One Million Community Health Workers Campaign, which is helping coordinate the deployment, that “this is the answer to universal health — to send in people to their homes to engage them, to share what they must do and what they mustn’t do to stay healthy.”

The World Health Organization estimates that more than 400 million people across the globe lack access to basic health services. Many live in remote locations like Abosamso, where it is impractical to build and staff health facilities within easy reach.

Ghana is one of numerous countries turning to CHWs. The idea is not new; the model has been around for about 80 years. The advent of village health workers, or so-called “barefoot doctors,” dates to China’s Rural Reconstruction Movement in the 1930s. But in recent decades, it has become established as a core pillar of efforts to advance global health. Countries like Ethiopia have employed the approach to slash maternal and child mortality rates, including a 64 percent drop between 2000 and 2015 in deaths among Ethiopian children under five years old.

In Ghana, the government has long relied on local volunteers to deliver health care services to those who live far from the nearest facility. But government officials say the needs are too great to rely too much on those volunteers, who can grow fatigued by the demands.

So now the Ghanaian government has begun to pay CHWs. Other countries have attempted similar initiatives, but the scale and the speed of Ghana’s effort make it distinctive. If it succeeds, it could signal a path toward universal health programs for other countries.

No one is following Ghana’s progress more closely than the American pediatrician and public health specialist Sonia Sachs. The four-year-old campaign is her brainchild, drawing on lessons from the Millennium Villages Project that her husband, the economist Jeffrey Sachs, started in 2004. That project, carried out across 14 sites in 10 countries, attempted to wed a variety of interventions to help lift rural communities out of poverty.

Among them were paid CHWs drawn from local areas. Though Sonia Sachs is still analyzing the research from the overall project, she says that “there were certain things that were obvious right then and there.” One of them was simply that paid CHWs “really save lives.” That spurred her to start the campaign.

Paying CHWs has long been a subject for debate, however. Some critics of the practice argue that it destroys a spirit of volunteerism that draws people to the positions in the first place. Communities and humanitarian organizations across the developing world have experimented with offering alternate incentives, including providing volunteers with T-shirts and bicycles. Others emphasize the social status conferred in being selected and trained as a CHW.

She cautioned, though, that as governments move to introduce paid CHWs, they must consider how they will maintain those programs. When Ethiopia began to pilot its now widely celebrated Health Extension Worker program in 2002, it pulled together a mixture of funds from regional governments, the national government and donors. The program now supports more than 38,000 health extension workers, but manages to pay them only about $35 per month — a small salary even by the standards of one of Africa’s poorest countries.

Starting in 2013, the Sachs team began working intensively with 10 countries on strategies to introduce or increase CHWs and pay them a minimum wage, even as it searched for outside funding to support those plans. The idea quickly gained traction in Ghana, a country that in 2000 had already begun a transition from a health system driven by where facilities existed, toward a new focus on delivery of services to communities in need.

That year the government began introducing basic health outposts around the country staffed with community health officers trained in community-based medicine who could circulate in their areas and boost prevention strategies. They also called on volunteers to supplement those efforts, but over time, Nsarko said, those volunteers became less and less engaged in those outreach efforts.

“They played a critical role in helping us,” he said. “But they always do this on an empty stomach.” In 2010, an evaluation of the health system showed worrying levels of fatigue among the volunteers. Officials became concerned about losing gains they had made, including an estimated drop of nearly 25 percent, between 2005 and 2015, in the number of children who died before reaching their fifth birthday.

By the time Sachs’s initiative approached them, officials were receptive to the idea of shifting some responsibilities to paid CHWs. The critical moment came in June 2015, when Sonia and Jeffrey Sachs pitched the idea to John Mahama, who was then Ghana’s president. Because of insufficient international support for the idea, Ghana would need to find ways to finance a paid CHW program domestically. The Sachses saw an opportunity to connect their efforts to the goals of Ghana’s Youth Employment Agency (YEA).

The agency had been formed to create jobs for secondary school graduates younger than 35, to help curb the country’s severe youth unemployment problem. It is funded by a tax on mobile phone users. The Sachs team suggested that if CHWs met the agency’s criteria, YEA could hire them and fold them into the health system.

Mahama agreed initially to use YEA to hire 5,000 of the more than 30,000 CHWs the campaign was requesting. The country’s parliament raised that number to 20,000 for two years at a cost of $25 million for the initial two years, enough to pay each CHW a salary of roughly $100 per month at the time the program started.

More than 100,000 young people applied for the positions when they were announced at the beginning of 2016, according to Nsarko, and the final 20,000 were selected after interviews with community leaders. Their training was completed by August and they were gradually deployed by the end of 2016.

The participants’ first task was to conduct a thorough survey of their communities. Each CHW was assigned roughly 100 households, and spent weeks going door to door asking about peoples’ health and noting those with potential needs like diabetics or women experiencing complicated pregnancies. They continue to make those rounds and follow up with people who require extra attention. And they will gradually take on more responsibilities, like coordinating vaccination campaigns.

Nsarko is anticipating results that exceed Ethiopia’s. While that country’s program focuses primarily on assisting mothers and young children, Ghana’s CHWs train to provide a range of emergency and preventive health services to everyone.

There have been some problems. While the government has agreed to pay the CHWs’ salaries, funding gaps remain. Some training sessions were shortened because money had run out, and there have been delays in payments to the CHWs since a new president, Nana Akufo-Addo, came into office in January. YEA officials said the interruptions were temporary, while they were cleaning up the payroll. Nevertheless, it remains unclear whether the new administration will be as committed to the program as Mr. Mahama was.

Back in Abosamso, Richard Appiah Kusi, a community health officer who helps oversee the CHWs, expresses confidence in them, saying that while the delays have caused anxiety, “they will not leave.”

“The CHWs,” he said, “are willing to work.”

Read the full story on The New York Times