Neglected Tropical Diseases in the 21st Century: A Comprehensive Review of Burden, Progress, and Persistent Gaps
Keywords:
NTDs, WHO targets, Comprehensive review, Global reports, Elimination of NTDs.Abstract
Background:
Neglected tropical diseases (NTDs) comprise a diverse group of 21 conditions that disproportionately affect the world’s poorest populations, perpetuating cycles of poverty, disability, and social exclusion. Despite being preventable and treatable, NTDs continue to impose a substantial global health burden.
Objective
This comprehensive review synthesizes the current epidemiological landscape, treatment and control strategies, and progress toward elimination targets for all 21 WHO-designated NTDs, while identifying persistent gaps that threaten the achievement of the 2030 roadmap goals.
Methodology
It is a comprehensive narrative review synthesizing published literature, WHO reports, and programmatic data on all 21 WHO-recognized neglected tropical diseases.
As of 2023, an estimated 1,495 billion people required interventions against NTDs, a decrease from the 2010 baseline. Between 2015 and 2021, the disease burden dropped from 17.2 million to 14.1 million disability-adjusted life years (DALYs), while NTD-related deaths decrease from approximately 139,000 to 119,000 in 2023 alone, 867.1 million people received treatment for at least one NTD. As of early 2026, 60 countries have eliminated at least one NTD, more than halfway toward WHO’’s 2030 target of 100 countries. However, significant gaps remain: global funding aid for NTDs declined by 41% between 2018 and 2023; climate change, population displacement and conflicts are emerging threats; and the 2030 targets risk not being achieved without renewed investment.
Conclusion
While remarkable progress has been achieved over the past two decades, sustained political commitment, innovative research, integrated approaches, and stable financing are essential to end the neglect of these diseases by 2030 and beyond.
References
1. Afroz, A., Siddiquea, B. N., Chowdhury, H. A., Jackson, T. N., & Watt, A. D. (2024). Snakebite envenoming: A systematic review and meta-analysis of global morbidity and mortality. PloS neglected tropical diseases, 18(4), e0012080. Available at: https://doi.org/10.1371/journal.pntd.0012080 (Accessed: 19 August 2026).
2. Akoachere, J-FKT, Nsai, F. S., Ndip, R. N. (2016). A community-based study on the mode of transmission, prevention, and treatment of Buruli Ulcers in Southwest Cameroon: knowledge, attitude and practices. PLoS ONE 11(5): e0156463. Available at: https://doi.org/10.1371/journal.pone.0156463 (Accessed: 28 July 2026).
3. Altcheh, J., Grossmann, U., Stass, H., Springsklee, M., & Garcia-Bournissen, F. (2025). Redefining the treatment of Chagas disease: a review of recent clinical and pharmacological data for a novel formulation of nifurtimox. PLoS neglected tropical diseases, 19(2), e0012849. Available at:
https://doi.org/10.1371/journal.pntd.0012849 (Accessed: 2 August 2026).
4. Arudchelvam, U., Pulendran, T. Sirimanne, M., Pabasara, S., Kahawita, I., & Chandraratne, N. (2025). Stigma of people affected by leprosy and its determinants: a cross-sectional study in Sri Lanka. BMC infectious diseases, 25(1), 148. Available at: https://doi.org/10.1186/s12879-025-10537-x (Accessed: 10 August 2026).
5. Baratti-Mayer, D., Pittet, B., Montandon, D., Bolivar, I., Bornand, J. E., Hugonnet, S., Jaquinet, A., Schrenzel, J., Pittet, D., & Geneva Study Group on Noma (2003). Noma: an “infectious” disease of unknown aetiology. The Lancet Infectious diseases, 3(7), 419-431. Available at:
https://doi.org/10.1016/s1473-3099(03)00670-4 (Accessed: 19 August 2026).
6. Bestwick, C., Badia-Rius, X., Lopes, S., Kelly-Hope, L. A., & Harding-Esch, E. M. (2026). Neglected tropical diseases in conflict-related humanitarian emergency settings: a systematic review of the literature. International health, 18(3), 328-336. Available at: https://doi.org/10.1093/inthealth/ihaf148 (Accessed: 10 August 2026).
7. Bhaumik, S., Karimkhani, C., Czaja, C. A., Williams, H. C., Rani, M., Nasser, M., Boyers, L. N. Dmitruk, S., & Dellavalle, R. P. (2015). Identifying gaps in research prioritization: The global burden of neglected tropical diseases as reflected in the Cochrane database of systematic reviews. Journal of family medicine and primary care, 4(4), 507-513. Available at: https://doi.org/10.4103/2249-4863.174266 (Accessed: 16 August 2026).
8. Bonifaz, A., Tirado-Sanchez, A., Calderon, L., Saul, A., Araiza, J., Hernandez, M., Gonzalez, G. M., Ponce, R. M. (2014). Mycetoma: Experience of 482 cases in a single center in Mexico. PLoS Neglected Trop Dis 8(8): e3102. Available at: https://doi.org/10.1371/journal.pntd.0003102 (Accessed: 28 July 2026).
9. Braimah, R. O., Butali, A., Mossey, P., Wendy, T., Taiwo, A., Coker, M., Bala, M., Ibikunle, A., Abdullah, S., & Bello, A. (2023). 1810. Noma (Cancrum oris): World Health Organization’s latest neglected tropical disease? Open Forum Infectious Diseases, 10(Suppl 2), ofad500.1639. Available at: https://doi.org/10.1093/ofid/ofad500.1639 (Accessed: 20 August 2026).
10. Bryson, J. M., Bishop-Williams, K. E., Berrang-Ford, L., Nunez, E. C., Lwasa, S., Namanya, D. B., Indigenous Health Adaption to Climate Change Research Team, & Harper, S. L. (2020). Neglected Tropical Diseases in the context of climate change in East Africa: A Systematic Scoping Review. The American journal of tropical medicine and hygiene, 102(6), 1443-1454. Available at:
https://doi.org/4269/ajtmh.19-0380 (Accessed: 10 August 2026).
11. Carlington, C. N., Melrose, W., Mokoia, G., Graves, P. M., Ichimori, K., Capuano, C., Kim, S. H., Aratchige, P., & Nosa, M. (2019). Elimination of lymphatic filariasis as a public health problem in Niue under PacELF, 1999-2016. Tropical medicine and health, 47, 20. Available at:
https://doi.org/10.1186/s41182-019-0141-1 (Accessed: 10 August 2026).
12. Carrion, C., Fuster, Casanovas, A., Nyangacha, R., Perez-Navarro, A., Aymerich, M., Vidal Alaball, J., Kinyeru, E., Quilter, E., Atieno, D., & Ruiz-Postigo, J. A. (2025). Evaluating the accuracy and usability of the WHO Skin NTD App as capacity building tool in Kenya. The European Journal of Public Health, 35(Suppl 4), ckaf161.214. available at https://doi.org/10.1093/eurpub/ckaf161.214 (Accessed: 14 August 2026).
13. Casulli, A. (2021). New global targets for NTDs in the WHO roadmap 2021-2030. PLoS neglected tropical diseases, 15(5), e0009373. Available at:
https://doi.org/10.1371/journal.pntd.0009373 (Accessed: 30 July 2026).
14. Chen, S. J., Rai, C. I., Wang, S. C., & Chen Y. C. (2025). Infection and Prevention of Rabies Viruses. Microorganisms, 13(2), 380. Available at:
https://doi.org/10.3390/microorganisms13020380 (Accessed: 19 August 2026).
15. Craig, A. T., Lawford, H., Mokoia, G., Ikimau, M., Fetaui, P., Marqardt, T., & Lau, C. L. (2025). Integrating post-validation surveillance of lymphatic filariasis with the WHO STEPwise approach to non-communicable disease risk factor surveillance in Niue, a study protocol. PLoS one, 20(1), e0315625. Available at: https://doi.org/10.1371/journal.pone.0315625 (Accessed: 10 August 2026).
16. da Silva, A. M. (2010). Human echinococcosis: a neglected disease. Gastroenterology research and practice, 2010, 583297. Available at: https://doi.org/10.1155/2010/583297 (Accessed: 29 July 2026).
17. den Boer, M., & Ritmeijer, K. (2026). Neglected tropical diseases in conflict zones: devastating consequences of a lack of inclusion. International health, 18(3), 313-315. Available at:
https://doi.org/10.1093/inthealth/ihaf165 (Accessed: 15 August 2026).
18. Donadeu, M., Gyorkos, T. W., Horstick, O., Lammie, P., Mwingira, U. J., Omondi, W. P., Pritchard, J. M., Tappero, J., Chan, Y. L., Welsche, S., Agua, J. F. V., Madjou, S., Mbabazi, P. S., Warusavithana, S., & Torres-Vitolas, C. A. (2025). Tracking progress along the WHO Neglected Tropical Diseases Road Map to 2030: A guide to the Gap Assessment Tool (GAT) and results from the 2023-2024 assessment. PLoS neglected tropical diseases. 19(7), e0013194. Available at:
https://doi.org/10.1371/journal.pntd.0013194 (Accessed: 12 August 2026).
19. Edward, M., & Owoicho, A. W. (2025). Leprosy elimination: are we winning the fight or losing focus? Annals of medicine, 57(1), 2604389. Available at: https://doi.org/10.1080/07853890.2025.2604389 (Accessed: 10 August 2026).
20. Franco, J. R., Priotto, G., Paone, M., Cecchi, G., Ebeja, A. K., Simarro, P. P., Sankara, D., Metwally, S. B. A., & Argaw, D. D. (2024). The elimination of human African trypanosomiasis: Monitoring progress towards the 2021 – 2030 WHO road map targets. PLoS neglected tropical diseases, 18(4), e0012111. Available at: https://doi.org/10.1371/journal.pntd.0012111 (Accessed: 9 August 2026).
21. Fried, B., Graczyk, T. K., & Tamang, L. (2004). Food-borne intestinal trematodiases in humans. Available at: https://doi.org/10.1007/s00436-004-1112-x (Accessed: 29 July 2026).
22. Gyamfi, E., Dogbe, M., Sarpong-Duah, M., Kyei-Baffour, E. S., Boateng, K. O., Asante, D. A., Ayelazuno, J. A., Quaye, C., Afouda, A. A., & Mosi, L. (2026). Comparative analysis of Buruli ulcer in Ghana and Cote d’Ivoire: A cross-sectional study. PLoS neglected tropical diseases, 20(1), e0013912. Available at: https://doi.org/10.1371/jpurnal.pntd.0013912 (Accessed: 9 August 2026).
23. Hayibor, K. M., Pamba, D. I., Banze, D. F. T., Mfinaga, A. A., Hanago, G. A., Singh, A., Froeschl, G., Hoffaeler, L., & Scholze, S. (2025). Proceedings from the CIHLMU International Health Symposium 2023: “One Health Approach to Neglected Tropical Diseases”. BMC proceedings, 19(Suppl 5), 2. Available at: https://doi.org/10.1186/s12919-025-00317-5 (Accessed: 7 August 2026).
24. Hietanen, H., Pfavayi, L. T., & Mutapi, F. (2025). Unlocking the blueprint to eliminating neglected tropical diseases: A review of efforts in 50 countries that have eliminated at least 1 NTD. PLoS neglected tropical diseases, 19(9), e0013424. Available at:
https://doi.org/10.1371/journal.pntd.0013424 (Accessed: 1 August 2026).
25. Hotez, P. J. (2008). Neglected infections of poverty in the United States of America. PLoS neglected tropical diseases, 2(6), e256. Available at: https://doi.org/10.1371/journal.pntd.0000256 (Accessed: 25 July 2026).
26. Hotez, P. J., Molyneux, D. H., Fenwick, A., Kumaresan, J., Sachs, S. E., Sachs, J. D., & Savioli, L. (2007). Control of neglected tropical diseases. The New England journal of medicine, 357(10), 1018-1027. Available at: https://doi.org/10.1056/NEJMra064142 (Accessed: 30 July 2026).
27. IGH, (2024). Impact Global Health, Smart Decisions: The G-FINDER 2024 Neglected Disease R&D Report. Available at: https://www.impactglobalhealth.org (Accessed: 20 August 2026).
28. Kumar, S. S., Yadav, N., Yadav, A., Srivastava, M., Kumar, S, & Jain, A. (2024). Leprosy in post-elimination era: A study conducted in rural tertiary settings in North India. Cureus, 16(5), e59464. Available at: https://doi.org/10.7759/cureus.59464 (Accessed: 10 August 2026).
29. Kumar, S., Alghamdi, A., Singh, P. K., Pal, N., Pattanaik, R., Alissa, M., Alghamdi, S. A., Abusalim, G. S., & Subhadra, S. (2026). Neglected tropical diseases: recent trends and challenges associated with its rapid diagnosis and effective therapeutic strategies. Frontiers in pharmacology, 17, 1742086. Available at: https://doi.org/10.3389/fphar.2026.1742086 (Accessed: 16 August 2026).
30. Laing, G. (2023). A year of One Health and neglected tropical diseases. International health, 15(5), 477-479. Available at: https://doi.org/10.1093/inthealth/ihad043 (Accessed: 7 August 2026).
31. Laing, G., Vigilato, M. A. N., Cleaveland, S., Thumbi, S. M., Blumberg, L., Salahuddin, N., Abdela-Ridder, B., & Harrison, W. (2021). One Health for neglected tropical diseases. Transactions of the Royal Society of Tropical Medicine and Hygiene, 115(2), 182-184. Available at:
https://doi.org/10.1093/trstmh/traa117 (Accessed: 7 August 2026).
32. Loftus, M. J., Trubiano, J. A., Tay, E. L., Lavender, C. J., Globan, M., Fyfe, J. A. M., & Johnson, P. D. R. (2018). The incubation period of Buruli ulcer (Mycobacterium ulcerans infection) in Victoria, Australia remains similar despite changing geographic distribution of disease. PLoS neglected tropical diseases, 12(3), e0006323. Available at: https://doi.org/10.1371/journal.pntd.0006323 (Accessed: 28 July 2026).
33. Malecela, M. N., & Ducker, C. (2021). A roadmap for neglected tropical diseases 2021-2030. Transactions of the Royal Society of Tropical Medicine and Hygiene, 115(2), 121-123. Available at: https://doi.org/10.1093/trstmh/trab002 (Accessed: 30 July 2026).
34. Marck, K. W. (2003). A history of noma, the “Face of Poverty”. Plastic and reconstructive surgery, 111(5), 1702-1707. Available at: https://doi.org/10.1097/01.PRS.0000055445.84307.3C (Accessed: 19 August 2026).
35. Marion, E., Hycenth, N., Vedithi, S. C., Robbe-Saule, M., Donkeng, V., Ganlonon, L. M., Dissou, A., Ngazao, S. K., Kabedi, M. J., Mabika Mabika, A., Phillips, R., Frimpong, M., Yeboah-Manu, D., Walker, V. Y., Akinwale, O., Issaka, M., Bretzel, G., Asiedu, K., & Eyangoh, S. (2022). A combined effort of 11 laboratories in the WHO African region to improve quality of Buruli ulcer PCR diagnosis: The “BU-LABNET”. PloS neglected tropical diseases, 16(11), e0010908. Available at:
https://doi.org/10.1371/journal.pntd.0010908 (Accessed: 14 Aug 2026).
36. Marks, M., Vedithi, S. C., van de Sande, W. W. J., Levecke, B., Solomon, A. W., Asiedu, K., Ducker, C. L., Lammie, P., Dagne, D. A., Cruz, I., & WHO Diagnostic Technical Advisory Group on Neglected Tropical Diseases (2024). A pathway for skin NTD diagnostic development. PloS neglected tropical diseases, 18(11), e0012661. Available at: https://doi.org/10.1371/journal.pntd.0012661 (Accessed: 14 August 2026).
37. Miri, E. S., Hopkins, D. R., Ruiz-Tiben, E., Keana, A. S., Withers, P. C., Jr, Anagbogu, I. N., Sadiq, L. K., Kale, O. O., Edungbola, L. D., Braide, E. I., Ologe, J. O., & Ityonzughul, C. (2010). Nigeria’s triumph: dracunculiasis eradicated. The American journal of tropical medicine and hygiene, 83(2), 215-225. Available at: https://doi.org/10.4269/ajtmh.2010.10-0140 (Accessed: 29 July 2026).
38. NCDC, (2017). Guinea Worm Disease – Dracunculiasis. Available at: https://ncdc.gov.ng (Accessed: 29 July 2026).
39. Ogbureke, K. U., & Ogbureke, E. I. (2010). Noma: A preventable “scourge” of African children. The open dentistry journal, 4, 201-206. Available at:
https://doi.org/10.2174/1874210601004010201 (Accessed: 20 August 2026).
40. Onwe, F. I., Okedo-Alex, I. N., Akamike, I. C., & Igwe-Okomiso, D. O. (2021). Vertical disease programmes and their effect on integrated disease surveillance and response: perspectives of epidemiologists and surveillance officers in Nigeria. Tropical diseases, travel medicine and vaccines, 7(1), 28. Available at: https://doi.org/10.1186/s40794-021-00152-4 (Accessed: 12 August 2026).
41. Otorkpa, O. J., Otorkpa, C. O., Adebola, O. A., & Anuniru, C. (2024). Resurgence of Noma (Cancrum oris) in Nigeria. The American journal of tropical medicine and hygiene, 111(6), 1164-1165. Available at: https://doi.org/10.4269/ajtmh.24-0406 (Accessed: 20 August 2026).
42. Otuneme, O. G., Obebe, O. O., Sajobi, T. T., Akinleye, W. A., & Faloye, T. G. (2019). Prevalence of Schistosomiasis in a neglected community, South western Nigeria at two points in time, spaced three years apart. African health sciences, 19(1), 1338-1345. Available at:
https://doi.org/10.4314/ahs.v19i1.5 (Accessed: 6 July 2026).
43. Patel, S. G., Modi, M., Darji, K., Darji, S., Jyotsna, Y., Subbaiah, P., & Tiwari, H. D. (2026). Neglected Tropical Diseases: Systematic Review. Journal of pharmacy & bioallied sciences, 18(Suppl 1), S23-S25. Available at: https://doi.org/10.4103/jpbs.jpbs_940_25 (Accessed: 30 July 2026).
44. Peterson, J. K., Bakuza, J., & Standley, C. J. (2020). One Health and Neglected Tropical Diseases – Multisectoral Solutions to Endemic Challenges. Tropical medicine and infectious disease, 6(1), 4. Available at: https://doi.org/10.3390/tropicalmed6010004 (Accessed: 7 August 2026).
45. Scarpini, S., Dondi, A., Totaro, C., Biagi, C., Melchionda, F., Zama, D., Pierantoni, L., Gennari, M., Campagna, C., Prete, A., & Lanari, M. (2022). Visceral Leishmaniasis: Epidemiology, Diagnosis, and Treatment Regimens in Different Geographical Areas with a Focus on Paediatrics. Microorganisms, 10(10), 1887. Available at: https://doi.org/10.3390/microorganisms10101887 (Accessed: 19 August 2026).
46. Sokunbi, T. O. Unnithan, V., Unim, B., Odhiambo, J., Dauda, Z., & Effiong, F. B. (2023). Trachoma elimination in Togo: lessons and recommendations for African countries. Pathogens and global health, 117(2), 99-100. Available at: https://doi.org/10.1080/20477724.2022.2136602 (Accessed: 19 August 2026).
47. Srour, M. L., Marck, K., & Baratti-Mayer, D. (2017). Noma: Overview of a Neglected Tropical Disease and Human Rights Violation. The American journal of tropical medicine and hygiene, 19(2), 268-274. Available at: https://doi.org/10.4269/ajtmh.16-0718 (Accessed: 19 August 2026).
48. Sullivan. M. (2025). Rethinking pharmaceutical development: A not-for-profit model to address global health inequalities. Future healthcare journal, 12(2), 100255. Available at:
https://doi.org/10.1016/j.fhj.2025.100255 (Accessed: 30 July 2026).
49. Tidman, R., Abela-Ridder, B., & de Castaneda, R. R. (2021). The impact of climate change on neglected tropical diseases: a systematic review. Transactions of the Royal Society of Tropical Medicine and Hygiene, 115(2), 147-168. Available at:
https://doi.org/10.1093/trstmh/traa192 (Accessed: 10 August 2026).
50. Tidman, R., Kanankege, K. S. T., Bangert, M., & Abela-Ridder, B. (2023). Global prevalence of 4 neglected foodborne trematodes targeted for control by WHO: A scoping review to highlight the gaps. PLoS neglected tropical diseases, 17(3), e0011073. Available at:
https://doi.org/10.1371/journal.pntd.0011073 (Accessed: 29 July 2026).
51. Uniting to Combat NTDs, (2025). A year in review: Uniting to Combat NTDs. Available at:
https://unitingtocombatntds.org (Accessed: 6 July 2026).
52. van de Sande, W. W. (2013). Global burden of human Mycetoma: A systematic review and Meta-analysis. PLoS Negl Trop Dis 7(11): e2550. Available at: https://doi.org/10.1371/journal.pntd.0002550 (Accessed: 28 July 2026).
53. Villacorta Linaza, R., Garner, T., & Genovezos, C. (2021). Building supply chain capacity for neglected tropical diseases: experience from the Ascend West and Central Africa programme. Transactions of the Royal Society of Tropical Medicine and Hygiene 115(8), 841-846. Available at:
https://doi.org/10.1093/trstmh/trab068 (Accessed: 15 August 2026).
54. WHO, (2015). Buruli ulcer Fact Sheet No 199. Updated May 2015. Available at:
www.who.int/mediacenter/factsheet/fs119/en/ (Accessed: 28 July 2026).
55. WHO, (2016). Buruli ulcer – diagnosis of Mycobacterium ulcerans disease. Available at:
https://www.who.int/news-room/fact-sheets/detail/buruli-ulcer-(mycobcterium-ulcerans-infection) (Accessed: 14 August 2026).
56. WHO, (2020). World Health Assembly. Road map for neglected tropical diseases 2021-2030. 33. Available at: https://www.who.int/publications/i/item/9789240000000 (Accessed: 12 August 2026).
57. WHO, (2022). Ending the neglect to attain the sustainable development goals. One Health: approach for action against neglected tropical diseases 2021-2030. Available at:
https://www.who.int/publication/i/item/9789240042414 (Accessed: 7 August 2026).
58. WHO, (2024). Buruli ulcer – diagnosis of Mycobacterium ulcerans disease: available at:
https://www.who.int/news-room/fact-sheets/detail/buruli-ulcer-mycobacterium-ulcerans-infection (Accessed: 9 August 2026).
59. WHO, (2025). Global report on neglected tropical diseases 2025: Executive summary. Available at:
https://www.who.int (Accessed: 30 July 2026).
60. WHO, (2026). Neglected Tropical Diseases: Global Update 2026. Available at: https://www.who.int (Accessed: 25 July 2026).
61. Witte, P., Venturini, S., Meyer, H., Zeller, A., & Christ, M. (2024). Dengue fever diagnosis, risk stratification, and treatment. Deutsches Arzteblattt international, 121(23), 773-778. Available at:
https://doi.org/10.3238/arztebl.m2024.0175 (Accessed: 28 July 2026).
62. Zhao, C., Ge, Z., Zhang, T., Jiang, Z., Tian, D., & Chen, Z. (2026). Chikungunya virus in 2025: Epidemiology, Immunopathogenesis, and Vaccine Development – A Narrative Review. Infection and drug resistance, 19, 567134. Available at: https://doi.org/10.2147/IDR.S567134 (Accessed: 28 July 2026).
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