It’s been five years since the the World Health Organization launched an ambitious “action plan” to bring some of the world’s least-known worst diseases under control. These so-called Neglected Tropical Diseases (NTDs) are a group of illnesses that affect the world’s poorest and most vulnerable populations. They occur primarily in hot countries, thus the word tropical. And none of them have a cure; thus the word neglected.
NTDs are present in 149 countries, and affect more than a billion people. And now, five years into a “roadmap” that has key inflection points in 2020 and 2030, it is clear that many of these diseases are on the decline.
We are witnessing — in real time — a global health success story in action.
The NTD control “roadmap” was launched in 2012 and built around four main approaches: Increasing the size of medicine donation programs so they could meet all demand by 2020, providing nearly $800 million to support elimination efforts, strengthening drug distribution and implementation programs, and sharing expertise and compounds to promote research and development of new medicines.
While it does have a research component, the roadmap focuses on scaling up proven approaches for targeting NTDs. This includes providing more of the drugs that have been shown to work and and rolling out existing prevention efforts. This is old school public health work. (On the rare occasion it mentions innovation, the roadmap describes innovative partnerships among existing global health agencies.)
There are currently twenty illnesses classified as NTDs according to the World Health Organization criteria (WHO). They are a rogue’s gallery of gross and distressing diseases: Buruli ulcer, a necrotizing disease of the skin and soft tissue; Chagas disease, a sleeping sickness; Dengue and Chikungunya, a related pair of viruses that are similar to Zika; Dracunculiasis, guinea-worm disease, also known as Jimmy Carter’s mortal enemy; Echinococcosis, an infection of tiny parasitic tapeworms; Foodborne trematodiases, a flatworm infection; Human African trypanosomiasis, or sleeping sickness; Leishmaniasis, an internal disease which is always fatal if untreated; Leprosy; Lymphatic filariasis, an infection of worms in the lymphatic system also known as elephantiasis; Onchocerciasis, also known as river blindness; Rabies; Schistosomiasis, a parasitic flatworm disease also known as snail fever; Soil-transmitted helminthiases – more worms; Taeniasis/Cysticercosis, two forms of infection by the same tapeworm; Trachoma, a bacterial eye infection and Yaws, an infection of the skin, bones and joints which causes painful swelling.
The 2012 Roadmap on NTDs – and where it has taken us
Of those twenty diseases, ten were selected as priorities for the 2012 coordinated plan. Those ten diseases have treatments or preventive measures that are proven to be effective, and the roadmap laid out ways to scale up those approaches. The results of the roadmap have been impressive. According to WHO:
1 billion people were treated for at least one neglected tropical disease in 2015 alone.
556 million people received preventive treatment for lymphatic filariasis.
More than 114 million people received treatment for onchocerciasis: 62% of those requiring it.
Only 25 human cases of Guinea-worm disease were reported in 2016, putting eradication within reach.
Cases of human African trypanosomiasis were reduced from 37,000 new cases in 1999 to fewer than 3000 cases in 2015.
Trachoma has been eliminated as a public health problem in Mexico, Morocco, and Oman. More than 185 000 trachoma patients had surgery for trichiasis worldwide and more than 56 million people received antibiotics in 2015 alone.
Visceral leishmaniasis: in 2015 the target for elimination was achieved in 82% of sub-districts in India, 97% of sub-districts in Bangladesh, and in 100% of districts in Nepal.
Only 12 reported human deaths were attributable to rabies in the WHO Region of the Americas in 2015.
What’s Next for NTDs?
Good progress doesn’t mean the effort stops now. There were only 25 guinea worm infections in 2016, but that’s not total eradication. We’ve done an effective job of improving diagnosis and treatment of NTDs, and of providing preventative medical treatments. The biggest remaining challenge is water and sanitation. As illustrated by the preponderance of worms in the list of NTDs, clean drinking water and safe disposal of human waste is the last mile of NTD control. That’s the last mile to a lot of global health goals; it’s also key to achieving the Sustainable Development Goals. Let’s hope that the global donor community can unite around it.