The progress towards a world free of neglected tropical diseases (NTDs) has been remarkable since the London Declaration on NTDs in 2012. The most important achievements have been the elimination of at least one NTD in 47 countries as well as the decrease of 80 million people needing interventions.
In 2021, ambitious targets were set up under the World Health Organization (WHO) NTDs 2030 road map. This involved a shift to disease elimination strategies for some specific diseases such as schistosomiasis, soil-transmitted helminths and onchocerciasis.
Having targets is important to raise the profile of these diseases among key decision makers at international and national level. They ensure these diseases are no longer neglected and the immense harm and suffering they cause is reduced.
But while some countries are successfully achieving the elimination of some NTDs and in large areas Mass Drug Administration (MDA) campaigns are stopping due to the decrease in prevalence, other countries are being left behind with a substantial lack of endemicity data and mapping gaps.
In WHO African Region (according to ESPEN portal) there are at least 13 countries without endemicity data for one or more preventive chemotherapy diseases (lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminths and trachoma). Understanding the burden of these diseases is critical to determine the public health interventions needed in an implementation area to get them on the road map to elimination.
Some reasons why large areas are not being sufficiently mapped include a lack of effective diagnostic tools and protocols, reduced resources and funding, and conflict-affected areas being logistically harder to reach with higher costs.
We need effective diagnostic toolsand agreed protocols to fill the mapping gaps for onchocerciasis. Developing novel target product profiles for new diagnostics is a priority to improve the diagnostic strategies for mapping of low-prevalence settings, for decisions to halt MDA and for post-validation surveillance.
Monitoring and evaluation protocols are currently under review for onchocerciasis, schistosomiasis and soil-transmitted helminths. The challenges in diagnostics, disease transmission and the varying concentration focality of diseases make this work significantly more difficult. But clear protocols will ensure countries can develop a mapping plan.
The use of modelling as well as artificial intelligence tools have remarkably progressed in the last few years and will be a supplementary tool to potentially solve mapping gaps or micro-mapping of certain diseases. Population movements might be a limitation for the use of these novel tools. Having the capacity to run sophisticated modelling tools might also be a barrier towards local implementation and ownership.
Local, skilled workers are often another challenge that countries face. The implementation of some mapping activities requires specific skills in entomology, epidemiology or data analysis. The planning and implementation these activities should be framed together with robust support to increase the local capacity, such as with entomological field and laboratory work. A good example of this practice is the work done with MENTOR support to map schistosomiasis and soil-transmitted helminths in Angola leading to subsequent locally-led mapping and impact assessment exercises.
Significant efforts have been jointly made among countries, donors, pharmaceutical companies and stakeholders to ensure funding, drugs and resources during the last two decades. Recently, under the Reaching the Last Mile Forum at COP28, global donors pledge over 777 million USD to tackle NTDs.
Despite the great progress and commitment, a lack of internal and external funding continues to be an issue when talking about disease mapping and monitoring and evaluation surveys. Baseline mapping in countries or regions not mapped for decades might be in a more difficult position attracting funding, as this is usually outlined at the start of a funding cycle so donors may not be willing to commit. Putting the focus on mapping gaps and issuing minimum information standards for country programmes to begin interventions may help to raise the alarm in these neglected areas.
Areas and countries suffering from humanitarian emergencies due to conflict are at highest risk of not meeting the 2030 NTD road map objectives. Conflict-affected countries such as Central African Republic, South Sudan, Chad or north-eastern Nigeria have major gaps in knowing the endemicity of at least one NTD. High levels of insecurity, limited access and lack of funding reliability negatively impacts the implementation of field activities.
Forced displacement is also on the rise in sub-Saharan Africa: 44 million people displaced in 2023, with 60% of people internally displaced. Questions have been raised about the validity of using the same monitoring and evaluation tools in areas where large population movements are taking place.
New approaches to address displaced communities, migrants and hard-to-reach groups are needed in all points of the intervention cycles. Such as including these communities in planning of activities, considering new implementation strategies during MDA campaigns and studying alternative sampling methods when monitoring and evaluation surveys are conducted. Integrating activities within existing community health networks could be a way to implement in such difficult situations. These approaches would require new funding mechanisms which include the evaluation and validation of the new methods.
Conflict-affected areas have significant challenges in terms of operations. Years of experience working in conflict scenarios have showed that it is possible to work in these difficult scenarios to effectively address NTDs in conflict-affected and displaced communities. Learning from other public health programmes and from other countries is paramount to move forward and adapt activities accordingly.
The NTD community should be more involved and take part in the humanitarian sector. Strong and long-standing public health interventions are included in humanitarian response such as vaccination campaigns, vector control (distribution of bed nets or indoor residual spraying campaigns) or cholera response. It is time to learn from these programmes and to integrate NTD programmes within the humanitarian sector.
This discussion goes beyond the five chemoprevention NTD diseases. The mapping gap is alarming when we want to know the prevalence or incidence of the other listed NTDs such as dengue, chagas, noma, scabies and foodborne trematodiases.
Next year, the NTD 2030 road map will be at the mid-point of the period it covers. If we want to keep all countries on board of the progress towards elimination, we must ensure that mapping gaps are immediately resolved and needed interventions begin.
As several countries progress towards elimination of one or more NTDs, the NTD community should not accept countries, regions and ultimately people being left behind without essential public health intervention.
It is time to look at the neglected amongst the neglected!