For more than two decades, Vestergaard has dedicated its innovative platform to product development and partner engagements aimed at reducing the burden of Neglected Tropical Diseases (NTD). At the heart of our efforts has been extensive work to decrease the incidence of sleeping sickness.
The Gambian form of Human African Trypanosomiasis (gHAT or sleeping sickness) is a vector-borne disease transmitted by tsetse flies which threatens over 56 million people in high-risk areas1,2. The difficulty with sleeping sickness lies in its complexity as there are no clinical signs specific to the disease, which makes diagnosis a challenge3. If detected, the stage of the disease is determined and involves an uncomfortable lumbar puncture4. However, if left untreated, HAT usually results in death5,6. As there is currently no vaccine or chemoprophylaxis for sleeping sickness, control of gHAT relies on vector control, diagnosis, and treatment. Integrating vector control into strategies focused on ‘screen-diagnose-and-treat’ has proven essential to move countries closer to the elimination goal.5,6
To accelerate elimination of gHAT, Trypa-NO! was launched in 2016 as a partnership between the Foundation for Innovative New Diagnostics (FIND), the French National Research Institute for Sustainable Development (IRD), the Liverpool School of Tropical Medicine (LSTM), and Vestergaard, with support by the Bill & Melinda Gates Foundation (BMGF)1. The goal of the partnership is to harmonize and integrate the screening, diagnosis, and treatment of sleeping sickness with tsetse fly control in Chad, Ivory Coast, Republic of Guinea, and Uganda. Supported by the project, ZeroFly® Tiny Targets are a cost-efficient intervention to control tsetse flies with the potential to eliminate gHAT in affected countries.7
Partnerships for elimination
Joseph Ndung’u is the Head of the NTD programme and the Executive Director of FIND Kenya. A veterinarian with a PhD in immunopathology of HAT, Professor Ndung’u has dedicated his career to Neglected Tropical Diseases (NTDs). In 2019, he received the African Union’s prestigious Excellence Award for his achievement and contribution to research and control of Tsetse and Trypanosomiasis. In this Q&A, Professor Ndung’u will address pertinent questions related to the progress on the elimination of sleeping sickness and the Trypa-NO! partnership.
It is true that both Uganda and Côte d’Ivoire have achieved the elimination of gHAT as a public health problem as defined by the WHO, considering the reported cases per year. However, validation of elimination by WHO is only done after the country has submitted a dossier, following WHO guidelines. In 2020, Côte d’Ivoire has submitted their dossier, and while the one for Uganda has been finalized, it is yet to be submitted. A major challenge to sustaining elimination is in implementation of long-term surveillance strategies that are not dependent on donor funding.
A) There will certainly be more such partnerships, and I believe that Trypa-NO! is not the first one, even for gHAT. We have seen it for example in drug donations. B) Control of both diseases is accelerated when both vector control and treatment of infected individuals is done. However, unlike gHAT, malaria is also prevented through chemoprophylaxis. Similarly, the elimination of both diseases is accelerated when both the disease and the vector are targeted. Elimination of gHAT could however be achieved faster than malaria because it is a very focal disease, and the transmission rate is much lower.
Reduction of tsetse fly densities reduces the rate of transmission of the disease, and if the reduction is sustained, transmission of the disease could eventually be interrupted. However, since gHAT is a chronic disease that lasts for months to years, infected individuals in a community remain reservoirs, and since tsetse flies still remain, such individuals would be the source for further transmission. Screening, diagnosis, and treatment of infected patients, removes their reservoir status, and when the two approaches are combined, the elimination process is accelerated.
In the HAT and NTD environment, FIND starts developing an access strategy at the time a decision is made to develop the diagnostic solution. Well aware that NTD control tools have no commercial interest, and that most countries where such diseases occur have limited capacity to procure the tools, FIND strives to mobilize resources, such that those tools become accessible to the people that need them, at minimal or no cost. A classic example is the Trypa-NO! partnership, through which vector control, screening and diagnostic tools are made accessible at no cost to the endemic countries and the affected communities. The contribution by countries is “in kind”. The greatest challenge is in making such an arrangement happen, but once it happens, the effort is worth it. The other challenge is in sustaining the effort when donor funding, or donations by companies come to an end – a big threat to sustaining elimination.
Head of NTD Programme at FIND
Executive Director FIND Kenya