Children gathered in Bamako in 2013Jerome Delay / AP

Even with futuristic advances in medicine and science, and increased access to food and other forms of nutrition, the oldest human health problem has remained stubborn—and, sometimes, seemingly impossible to fix: Young children and infants still die at epidemic rates in the poorest corners of the globe. Those deaths are linked to every other health-care challenge those areas of the world experience, from the prevalence of fever illnesses to the limited availability and quality of care. The mortality rates of young children are the key indicator of individual, community, and economic health of a given place. And in areas from sub-Saharan Africa to southern Mississippi, elevated rates indicate communities in distress.

But one program in the West African nation of Mali may illuminate a path to solving this most vexing human problem. A new study published in BMJ Global Health indicates that a pilot program in the capital city of Bamako has been extraordinarily effective at reducing child mortality. And it’s the way that pilot program addressed the problem in Mali that makes it intriguing in a global context: by expanding free health care to everyone, and using that free care to extend basic public-health surveillance and response mechanisms to everyone.

Bamako was a critical location for researchers to study, as it represents a number of disconcerting issues related to global child mortality. Recently the fastest-growing city in Africa and one of the fastest-growing cities in the world, Bamako is a picture of the rapid urbanization of the African continent and, more generally, the global south.

This urbanization brings people in closer proximity to health-care and financial resources. But the creation of peri-urban rings of slums, where there’s concentrated poverty and degraded environments, can actually make them more “vulnerable to infectious diseases such as malaria, diarrhoea and pneumonia, to new pandemic outbreaks and to an emerging non-communicable disease burden,” according to the study. That urban structure places Bamako at the center of two competing trends. While Mali is still among the worst places on Earth in terms of infant and child mortality, its overall burden is decreasing over time as advancements in aide, medicine, nutrition, and access to care spread. But that progress could still be threatened by continuing urbanization.

According to Ari Johnson—a physician who is the lead author of the study and a co-founder of Muso, the small nonprofit that launched the pilot program in question—there are a number of health-care barriers that characterize child mortality in Mali, where in 2015, 114 out of 1,000 children died by the age of five.* One of those barriers is cost. “The World Health Organization has estimated that 100 million people every year are driven into poverty by health-care costs,” Johnson said. “Fees are one of the most important barriers that delay or prevent patients—particularly poor patients—from accessing care in time.”

Muso’s 2012 analysis of Mali’s health-care system illustrates those cost barriers using the example of the Yirimadjo area. That study found that “user fees for health care not only decreased utilization of health services, but also resulted in delayed presentation for care, incomplete or inadequate care, compromised food security and household financial security, and reduced agency for women in health-care decision-making.”

In addition to the costs of Mali’s fee-for-service health-care system, Johnson identified several other issues that poor people in the slums of Bamako face that lead to child mortality. “So much depends on when someone gets access to care,” Johnson said. “An illness like malaria can progress and kill within hours of the first symptom. And we also know that patients facing extreme poverty are most likely to get care late or not at all.”

In Mali, as in other sub-Saharan African countries, there are ongoing efforts to overcome those difficulties. Several are “community case management” initiatives, created to diagnose, treat, or refer ill children, especially those at risk for malaria or other deadly fever diseases. The WHO and UNICEF have promoted programs like these for over a decade, and in Mali they’ve been used to address malaria, diarrheal diseases, malnutrition, and pneumonia. But they’ve been implemented primarily in rural contexts—not in any way that could cut through the mountainous disparities at the edges of Mali’s biggest city.

Johnson and his team, along with a group of government officials, decided in 2008 to put an innovative twist on the community case-management model in the outskirts of Bamako. Their model centered on training community health workers to proactively seek out children with developing illness or fevers. At the same time, they utilized the workers for so-called doorstep care—house calls for mild illness or management of chronic illness—as well as group-supervision visits. Researchers created systems for rapid response and referral of sick patients to health centers, and reinforced the health centers’ operations with training and funding. The workers were drawn from their own communities—with a special focus on recruiting women—and their ranks expanded over time so there’d be a ratio of one worker to 1,000 community  members. Critically, the intervention eliminated all fees for community-based care, as well as fees at health centers for patients who couldn’t pay.

After seven years, the results of this intervention—called proactive community case management, or ProCCM—in the targeted communities appeared unambiguous. The study found that targeted communities saw child mortality rates at or below 28 deaths per 1,000 children for six straight years—a sustained drop that’s about a quarter of Mali’s rate countrywide. The study found that child death rates in 2015 were seven deaths per 1,000 children, a number roughly similar to that of the United States. According to Johnson, “we also found that the percentage of sick kids with fever was cut by about half by the end of the study.”

While the study didn’t feature a control group to establish causality—Johnson tells me one such study is under way—the results nevertheless seem promising. ProCCM interventions focused on speed and lowering barriers to care in communities where the rapid course of fever has often overwhelmed families that simply cannot seek treatment quickly. “We believed that the study’s important because it reframes what’s possible,” Johnson said. “It shows that even in settings of extreme poverty and inequity, achieving universal health coverage, health equity, and child survival are achievable.”

But the most remarkable piece of this study is perhaps what it says about health-care systems. The most significant component of the ProCCM model was simply making health care free, and shifting the costs to Muso and the government, increasing their spending by about $8 per person. Doing so removed the biggest barrier to care, and allowed some of Mali’s poorest citizens to access a network of providers. The rest of ProCCM’s innovations involved pretty basic public-health stuff: community-led health work, surveillance and rapid response, group health care, and subsidized acute-care transportation and delivery.

“One of the keys of the study is that it studied a package of interventions and tools that are relatively simple to implement and scale, and the cost of making this happen is relatively modest and affordable for the international community and governments,” Johnson said. “The principles that we’re applying here and putting together are foundational ones.”

Pending the results of the larger clinical trial, ProCCM may or may not be the right answer for Bamako or Mali; it could prove difficult to fund or scale. But the study seems to demonstrate some basic lessons: Health care is too expensive for many people, and making it free and universal helps them access it. And when people do have access to care, it’s the fundamentals—like having nurses or doctors from the community—that often matter most, not expensive “disruptions” from major companies. Those lessons appear universal, whether on the poor outskirts of a sprawling global city or in the Mississippi Delta.

* This article originally identified Ari Johnson as the founder of Muso. He’s a co-founder. We regret the error.