Some diseases persist not because we don't know how to prevent or treat them, but because they occur in the wrong places.

They are not rare, new, or unknown. They affect more than 1 billion people and yet remain outside the center of the global conversation—not because of medical failure, but because of a silent logic: they don’t create urgency where decisions are made.

So-called neglected tropical diseases thrive where access to clean water, basic sanitation, and strong health systems is lacking. They are concentrated in regions of Africa, Asia, and Latin America, but they don’t belong exclusively to those maps. Above all, they belong to a system that has learned to coexist with certain levels of suffering without finding it unacceptable.

Their names often sound distant or complex: hookworm infection, ascariasis, schistosomiasis, fascioliasis. Others are more familiar, such as dengue, leprosy, or rabies. These are not laboratory terms or medical curiosities—they are infections that cause chronic pain, anemia, malnutrition, neurological damage, blindness, physical deformities, and social stigma. In many cases, the consequences last a lifetime.

These diseases do not appear at random. Their persistence is directly linked to specific structural conditions.

• Lack of access to safe drinking water and sanitation promotes parasitic and intestinal infections transmitted through contaminated water or food, such as ascariasis, hookworm infection, dracunculiasis, fascioliasis, and trachoma.
• Precarious housing and overcrowding facilitate the presence of disease-carrying insects and prolonged human contact, conditions associated with diseases such as Chagas disease, leprosy, and yaws.
• The absence of vector control allows the spread of mosquitoes and other insects that transmit diseases like dengue, leishmaniasis, lymphatic filariasis, and onchocerciasis.
• Frequent contact with contaminated water—especially rivers or lagoons without sanitary control— exposes people to parasites and bacteria responsible for diseases such as schistosomiasis and Buruli ulcer.
• Finally, the lack of animal and food health controls favors infections transmitted through consumption or direct contact, such as cysticercosis and rabies.

For years, these diseases were framed as a purely health-related problem. But the issue was never only medical. Science understands these conditions, knows how to prevent many of them, and how to treat them if detected early. What is often missing is sustained investment, access to early diagnosis, and health policies that prioritize populations with low global visibility.

The term “neglected” is no coincidence. These diseases receive less funding for research, fewer prevention campaigns, and less media attention than other equally serious conditions—not because they are untreatable, but because they primarily affect poor communities. Poverty, lack of clean water, and inadequate sanitation are not just background factors; they are active components of the problem.

What’s most troubling is that the world has grown accustomed to this reality. Accepting that millions of children and adults live with preventable infections has become part of the global landscape. Some of these diseases do not kill immediately, but they limit, deform, and exclude. And that slowness makes them tolerable for a system that prioritizes urgency over persistence.

That balance is beginning to crack. Climate change is expanding the range of mosquitoes and other vectors, pushing diseases into urban and peri-urban areas. Some NTDs are no longer confined to remote regions—they appear wherever sanitary conditions fail, even near major cities. What once felt distant is moving closer.

Talking about neglected tropical diseases is, at its core, a conversation about global priorities. About which lives trigger immediate action and which are left waiting. As long as illnesses persist not because solutions are lacking, but because will is lacking, the problem will not be medical. It will be ethical.

This January 30, the call is clear: look where almost no one looks—and start acting.

In a hyperconnected world, continuing to look the other way is no longer a sustainable option. Because health knows no borders—and indifference is not a lasting barrier.