Neglected Tropical Diseases
The Billion People Medicine Forgot
There is a class of diseases that blinds children, dissolves skin, and traps entire communities in poverty — and most people in wealthy countries have never heard a single one of their names.
The Idea
Neglected tropical diseases — NTDs — is the official term used by the World Health Organization for a group of more than twenty infections that persist almost exclusively among the world's poorest populations. They include names like schistosomiasis, lymphatic filariasis, trachoma, onchocerciasis, and soil-transmitted helminths. Together, they affect roughly 1.7 billion people, primarily in sub-Saharan Africa, South Asia, and Latin America. They rarely kill outright, which is partly why they stay off the radar. What they do instead is subtler and in some ways more devastating: they cause chronic disability, disfigurement, cognitive impairment in children, reduced work capacity, and a stigma so severe that it can make someone unmarriageable in their community. This is the trap inside the trap. NTDs don't just cause suffering — they actively prevent the kind of economic and social mobility that might allow someone to escape the conditions that caused the disease in the first place. The neglect in the name is not accidental. These diseases receive a fraction of global health research funding relative to their burden, largely because the people they affect have no market power. Pharmaceutical companies have little incentive to develop treatments for populations who cannot pay premium prices. What makes NTDs one of the most striking moral puzzles in global health is that many of them are extraordinarily cheap to treat — sometimes just a few tablets per person per year.
In the World
Consider trachoma, a bacterial eye infection and the world's leading infectious cause of blindness. It spreads through contact with eye discharge — on hands, shared cloths, flies attracted to unwashed faces — and is entirely a disease of poverty and limited water access. Repeated infections over years cause the eyelid to scar and eventually turn inward, so that every blink drags the eyelashes across the cornea like sandpaper. The condition is called trichiasis, and it is as painful as it sounds. By the time blindness sets in, the person has often lost years of productivity and, in many communities, their social standing. The surgery to correct trichiasis before it causes permanent damage costs roughly the equivalent of a single takeaway meal in a wealthy city. For decades, trachoma was endemic across much of the Middle East and North Africa. Morocco, once one of the world's most trachoma-affected countries, eliminated it as a public health problem by 2019 — through a combination of mass antibiotic distribution, face-washing campaigns, and latrine construction. Morocco's success was not a miracle of new technology. It was the application of existing, cheap tools, sustained over time, with political will. The disease didn't need a cure. It needed attention.
Why It Matters
On a Self Sunday, you might wonder what diseases affecting a billion people in distant places have to do with your inner life. But NTDs are a sharp lens on a question that matters to anyone trying to live thoughtfully: how do we decide what deserves our moral attention? Research in psychology consistently shows that humans respond to identifiable individuals — one child with a name and a face — far more than to statistics representing millions. NTDs suffer from exactly this. They are faceless, chronic, and geographically remote from the audiences with the resources to help. Knowing this bias exists in your cognition does not dissolve it, but it does allow you to work around it. If you care about where your time, energy, or generosity goes — and most people reading a lesson like this on a Sunday morning do — then understanding NTDs is a practical exercise in expanding your circle of concern beyond what your emotional architecture naturally defaults to. It is also, quietly, a reason for genuine optimism: these are problems that yield to organised effort. The tools largely exist. What has been missing, again and again, is simply the decision to pay attention.
A Question to Ponder
Is there a form of suffering you've been unconsciously filtering out — not because you don't care, but simply because the right story about it has never reached you?
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