What do people do when they get the first indication that they might be seriously ill? What do they do next? Where do they go from there?

Such questions are increasingly being asked by public health scholars, ethnographers, and medical anthropologists who are studying the so-called “therapeutic itineraries” of everyone from malaria sufferers in Gambia to diabetics in Brazil.

Nearly all the research, so far, has been done the old-fashioned way: by interviewing people. When three researchers asked 12 breast cancer patients from central Mexico, for instance, what each did right after discovering a lump in her breast, the women’s answers revealed a dozen different health care routes—paths that led, in some cases, to markedly different outcomes. Some women got their definitive cancer diagnosis within three months of discovering a suspicious lump, others not until 18 months later.

Therapeutic itineraries can help pinpoint the weak joints in a given healthcare system, the barriers and bottlenecks that delay care or limit access to it. They can also reveal failures in communication that, if corrected, might dramatically improve outcomes.

Consider the case of malaria. Despite significant progress made against the disease over the past decade, it remains endemic in much of Africa. One still-unsolved problem is that infected individuals who come late to treatment can serve as a reservoir for new infections. And a recent study of therapeutic itineraries of infected individuals in rural Gambia, led by Sarah O’Neill of the Institute of Tropical Medicine in Antwerp, shows at least one reason it’s often hard to find and treat them earlier.

In some West African traditions, the graver symptoms of severe malaria—disorientation, fainting, convulsions—are thought to be caused by non-human spirits, and so a common first stop is to a traditional healer rather than a modern health clinic. Even the term “malaria,” O’Neill and her colleagues explain, is “considered to be a ‘toubab’ (meaning ‘white man’) word.” The underlying sickness is described differently by the Mandinka people and the Fula, and by the Soninke and the Wolof—and in ways that don’t always translate to either the same disease or the same urgent message: “Go to the clinic right away.”

“Healthcare activities are social responses organized to face diseases and can be understood as a cultural system,” write two itinerary trackers from Brazil. That system includes not just the providers of modern medicine—the people and institutions we mostly focus on—but also our families, friends, social networks, search engines, online communities, and more.

Think about that a minute: Healthcare activities are inherently social—informed by social rules and customs.

And what that means, dear Daily readers, is that any broad-based public health intervention that doesn’t address that component isn’t likely to succeed.

Happy Friday.