Neglected Tropical Diseases
As a group, neglected tropical diseases (NTDs) affect more than 1 billion people – and cost economies billions of dollars – every year. These diseases have suffered a historical lack of attention, largely because they thrive in conditions of poverty.
Beyond their neglect, NTDs have little in common, being caused by a variety of pathogens, ranging from viruses to bacteria, fungi, protozoa, and helminths. In 2012, the original WHO Roadmap on NTDs set out specific targets for disease control, elimination and, in some cases, eradication that prioritizes the needs of affected communities rather than individual diseases, for example through the strengthening of health systems. These efforts have catalysed action to fight these diseases, and shown that NTD investment is one of the “best buys” in global public health. But while substantial progress has been made, a new 2021–2030 Roadmap highlights critical gaps that still need to be filled to reach the 2030 targets, and stresses the need for multisectoral action, particularly for diagnostics.
Diagnostics are critical tools for disease control and elimination. They are imperative for surveillance, with large-scale screening initiatives needed to track down the last cases so that they can be treated and do not become a source of infection for others. Diagnostics can confirm or rule out disease following a positive screening test. They are also a crucial complement to treatment strategies, monitoring treatment response in individuals as well as the success of public health initiatives such as mass drug administration.
Our NTD portfolio focuses on diseases with significant unmet diagnostic needs.
Human African trypanosomiasis (HAT; also known as sleeping sickness), is a protozoan disease that is transmitted to humans through the bite of an infected tsetse fly. Just a century ago it caused regular epidemics but is now nearing elimination, with some countries seeing less than a handful of cases in recent years – finding the remaining cases is challenging in remote settings.
Leishmaniasis is also caused by protozoan parasites. This disease is transmitted to humans when they are bitten by infected sand flies. There are different forms of the disease: cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL), also known as kala-azar, the most common forms, respectively. Recurrent outbreaks are a major concern, but control and elimination efforts are now gaining ground. Identification of patients with CL and VL is significantly complicated by the fact that the symptoms are not specific, and so diagnostic tests are the only way to confirm the disease.
Schistosomiasis an infection caused by parasitic worms and is transmitted when someone comes into contact with contaminated water, allowing the young worms (released by freshwater snails) to penetrate human skin. Unlike HAT and leishmaniasis, over 200 million people are affected in tropical and sub-tropical countries, with most of the burden found in sub-Saharan Africa. The disease is controlled through mass drug administration. Identification of communities requiring treatment depends on accurate diagnosis, which requires multiple samples collected over several days to be analysed by highly trained microscopists. Also, diagnostics for the correct assessment of treatment success is essential as inaccurate results can lead to the drug administration programmes being stopped too soon, and infections quickly returning to initial levels.
Buruli ulcer is a stigmatizing disease caused by a bacterium that belongs to the same family as those that cause TB and leprosy, but its exact mode of transmission is unknown. Cases have been reported in countries across Africa, the Americas, Asia, and the Western Pacific, with most cases occurring in tropical and subtropical regions. While the number of cases is declining, Buruli ulcer impacts tens of thousands of people, and children are particularly vulnerable. Early diagnosis and treatment are critical to minimizing the impact of the illness and prevent disability.
Chagas disease, which is caused by the parasite Trypanosoma cruzi, affects 6 to 7 million people, most of whom live in one of 21 Latin American countries where Chagas disease is endemic. However, only a small fraction of the people infected have access to diagnosis and treatment. Furthermore, the congenital transmission of T. cruzi remains a source of incident cases, even in non-endemic regions such as Europe. Simple diagnostic solutions should be developed and implemented to improve access to diagnosis and treatment and interrupt T. cruzi transmission in endemic countries.
Together with our partners and donors, we are working on diagnostic solutions that can address the lack of readily available, easy-to-use, reliable and low-cost diagnostic tools to identify infections, detect disease re-emergence, monitor the impact of mass drug administration and guide delivery of appropriate control measures.
- Interrupt transmission of HAT, Buruli ulcer and visceral leishmaniasis (Indian subcontinent) through early diagnosis.
- Drive elimination of schistosomiasis through improved diagnostics.
Neglected Tropical Diseases R&D pipeline
|Catalyse Development||Guide Use and Policy|
|Schistosoma: RDT (Mologic)||Buruli: LAMP (DITM, NMIMR)||Buruli: fTLC (Harvard, WHO)||HAT: 2nd generation RDT (SD/Abbott)|
|Buruli: mycolactone RDT (DDTD)||Buruli: Ag capture (SD/Abbott,
|Leishmania: Rk28 RDT for WHO
|HAT: malaria combo RDT (SD/Abbott)|
Download our full R&D pipeline.