Brice Rotoreau, Etienne Walleck, Vincent Gamono, Philip Solano, Sophie Molia, Patrice Depre, Cossai Delaghi, Serge Morand
Correspondence with Dr. Brice Rotoreau; email@example.com
Most neglected tropical diseases (NTDs) are intrinsically integrated into the One Health approach: NTD researchers have already dealt with multidisciplinary and intersectoral work for decades simply because it is necessary to understand and control the normally complex transmission of NTDs-causing pathogens.
This long experience has already established the idea of horizontal integration of search, control, eradication and eradication strategies.
The ongoing epidemiological transformations of most NTDs prompt the follow-up and amplification of the development of intersectoral and multidisciplinary research initiatives to improve control/elimination/eradication.
Lessons learned from NTDs may also be useful for other diseases targeted by One Health’s ongoing initiatives.
Introduction: neglected tropical diseases
Neglected tropical diseases (NTDs) represent a group of 20 diseases that affect more than 1 billion people in 150 countries, mostly in Africa, Asia and the Americas. They are considered “signs of stigma and poverty”, because of their debilitating consequences, often also affecting mental health, and because they primarily affect the poor, vulnerable and marginalized. Neglected tropical diseases cause significant social and economic losses to individuals, families, communities and countries. Despite the huge impact amounting to billions of dollars annually, only 0.6% of global healthcare funding is allocated to these diseases, notwithstanding the negative impact of the COVID-19 pandemic that remains difficult to quantify.
However, in the past decade, the study of NTDs in global health has developed and gained momentum. This has been announced through the adoption of the WHO Neglected Tropical Diseases Roadmap in 2011, the 2012 London Declaration, the launch of the 2030 Sustainable Development Goals specifically referring to NTDs, and most recently the new WHO Roadmap 2021- 2030 on neglected tropical diseases. These initiatives aim to draw the attention of stakeholders to diseases that often remain off the tracks of major health programmes: “leave no one behind”. In the Francophone world, the International Francophone Organization wrote a specific resolution on NTDs at the 2018 Erevan Summit, and the “Francophone Network on NTDs” reiterated its strong support for the new WHO 2030 roadmap for neglected tropical diseases. In this roadmap, specific objectives, including scientific research objectives, are defined for each NTD according to its epidemiological status: control, elimination of a public health problem, elimination of transmission and/or eradication (Box 1).
Frame Definitions 1
control: The control goal is to achieve a local reduction of disease prevalence to an acceptable level – this usually requires continuous interventions to maintain this decline. Significant efforts are usually required in both cognitive and applied research in parallel to reach the next exclusion step.
Elimination of public health problem (ephp), by the process of “verification”: ephp targets the overall achievement of certain measurable goals. When this process is achieved, the WHO can validate the process, however action still needs to be taken to maintain the goal and/or progress towards eliminating transmission. Compiled search is very useful for this step.
Elimination of transmission (eot), which requires ‘verification’: eot aims to reduce the incidence of NTD to zero in well-defined areas, with minimal risk of re-introduction. This process is being verified by the World Health Organization and further action may be necessary to prevent a recurrence of the disease. Here it is also necessary to maintain a minimum level of applied research.
eradication, which needs ‘certification’: Ultimately, the goal of eradication should result in the permanent reduction of the given pathogens to zero, without the risk of reintroduction. This process requires WHO certification.
By definition, neglected tropical diseases have rarely been prioritized in research and surveillance work programs in endemic countries. Conventional vertical intervention schemes were initially used successfully with some neglected tropical diseases, for example, prevention or treatment of geohelminthiasis through bulk drug administration using cheap, stable and safe oral medications. However, the intrinsic complexity of pathogen life cycles and the limited resources devoted to NTDs have promoted alternative strategies to classical vertical approaches. Hence, interdisciplinary research approaches at fundamental, translational and applied levels have gradually flourished in the field of NTDs by necessity, to improve scientific knowledge in the service of control interventions. We believe that lessons learned from NTDs may be useful for other diseases targeted by One Health’s ongoing initiatives.