NTDs

Neglected tropical diseases (NTDs) are a group of communicable diseases that prevail in tropical and subtropical regions, particularly among populations living in poverty with limited access to clean water, sanitation, and healthcare. They are termed neglected because they have historically received less attention and funding than other communicable diseases, despite causing substantial illness, disability, and social stigma. NTDs tend to be chronic, sometimes disabling, and can perpetuate cycles of poverty through their impact on growth, education, and productivity.

The range of NTDs is diverse, including several infections caused by helminths (worms), such as soil-transmitted helminths (roundworms, whipworm, hookworm) and schistosomiasis; vector-borne diseases such as dengue, lymphatic filariasis, onchocerciasis, and leishmaniasis; and bacterial infections such as trachoma, yaws, and buruli ulcer. Other major NTDs include Chagas disease and human African trypanosomiasis (sleeping sickness).

NTDs affect hundreds of millions of people and cause a heavy burden of morbidity, including anaemia, malnutrition, organ damage, vision loss, and chronic pain. They most affect rural and peri-urban communities in low-income countries and can hinder education by affecting cognitive development and school attendance.

Control relies on integrated programs that combine preventive chemotherapy (mass drug administration), vector control, safe water and sanitation, insecticide-treated nets, case management, and health education. Vaccines are under development for several NTDs. International partnerships, drug donations, and WHO guidance—often summarized in the WHO NTD Roadmap and outcomes of the London Declaration—aim to reduce prevalence and eventually interrupt transmission for selected diseases.