What Makes A Condition A ‘Neglected Tropical Disease’?

The World Health Organization's list of neglected tropical diseases (NTDs) is more than a bureaucratic classification—it determines access to global funding, research attention, and public health interventions. Advocacy groups have fiercely lobbied for inclusion, turning the list into a high-stakes battlefield over which diseases deserve the 'neglected' label.

The WHO currently recognizes 20 NTDs, ranging from dengue and rabies to leprosy and snakebite envenoming. Inclusion is not automatic: a condition must meet strict criteria. It must primarily affect populations in tropical and subtropical regions, impose a significant health and economic burden—often pushing families into poverty—and be largely overlooked by mainstream research and funding. Crucially, there must be proven, cost-effective tools (drugs, diagnostics, or vector control) to intervene. The WHO's Strategic and Technical Advisory Group for NTDs (STAG-NTD) reviews applications and recommends additions.

The list originated in the early 2000s as a way to spotlight diseases that were chronically underfunded despite devastating billions. Over time, conditions like lymphatic filariasis, onchocerciasis, and schistosomiasis were included. More recent additions—scabies in 2017, snakebite envenoming in 2017, and chromoblastomycosis in 2024—were driven by sustained campaigns from patient groups, NGOs like the Drugs for Neglected Diseases initiative, and endemic-country governments.

Advocacy groups push hard because inclusion unlocks resources. The WHO list triggers funding from major donors like the Bill & Melinda Gates Foundation, the Global Fund, and USAID. It also aligns pharmaceutical companies to donate treatments through the London Declaration on NTDs and subsequent commitments. For example, after scabies was listed, investment in ivermectin mass administration programs increased. Conversely, conditions that fail to make the list—such as Buruli ulcer (already listed) or mycetoma (listed in 2017)—face years of invisibility.

The debate over what qualifies is intensifying. Some critics argue the criteria are too rigid, excluding conditions that primarily affect the poor in non-tropical regions (like Chagas disease in parts of the Americas). Others say the list should focus on diseases with effective interventions, not just burden. The WHO is updating its methods, incorporating a broader 'neglect metric' that accounts for inequity in research and development.

Looking ahead, advocates are campaigning for inclusion of conditions like melioidosis, podoconiosis, and even parasitic dracunculiasis (which is nearly eradicated but remains on the watch list). The next STAG-NTD meeting in 2027 will review new applications. The outcome will shape global health priorities for a decade. As one expert put it, 'Getting on the list is not just a label—it's a life-or-death decision for millions who have no voice.'