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.

Read more about addressing child mortality by Vann R. Newkirk II at The Atlantic