Taking the neglected out of neglected tropical diseases
Authors: None The Lancet Global Health
Journal: The Lancet Global Health (2020)

In December, 2019, Nairobi, Kenya hosted the first international conference on neglected tropical diseases (NTDs) in Africa. The theme, “cross-border partnership towards achieving control and elimination of NTDs”, recognised that cooperation beyond national borders is crucial for success in the fight against NTDs. The importance of collaboration to control NTDs came to global attention in 2012, with the launch of the WHO Roadmap on NTDs 2012–20 and the London Declaration on NTDs, which saw governments, donors, multilateral agencies, non-governmental organisations, and pharmaceutical companies coming together to commit to control, eliminate, or eradicate ten of WHO's priority NTDs by 2020. Jan 30 will mark 8 years since the London Declaration on NTDs. That same date will also mark the inaugural World NTD Day. From blinding trachoma to schistosomiasis, this diverse, distinct set of diseases can have catastrophic consequences if left untreated, keeping people out of work and causing disfigurement, disability, and death. It is estimated that 1·6 billion people worldwide are affected by NTDs, and 149 countries are endemic for at least one NTD. These diseases thrive in areas where access to health care, sanitation, and clean water are inadequate, often leaving the poorest in society to bear the brunt of the burden. Understanding the complex interplay between socioeconomic, cultural, demographic, and ecological factors in these settings is part of the challenge in beating them. Indeed, a glance through our archive shows a range of research under the umbrella of NTDs, from estimating the burden of dengue in India, to mapping the global distribution of Buruli ulcer, to uncovering the socioeconomic determinants of leprosy in Brazil. 2020 is set to be a pivotal year for NTDs as the first roadmap ends and WHO finalises the Roadmap 2021–30 within the framework of the Sustainable Development Goals. Of the five strategic approaches recommended by WHO (preventive chemotherapy, intensive disease management, vector and host control, veterinary public health, and provision of safe water, sanitation, and hygiene), mass drug administration has been particularly successful. In 2018, for the fourth consecutive year, more than 1 billion people were treated for at least one of the five NTDs targeted for control and elimination. Intensive disease management through improved case detection and decentralised clinical management is recommended for complex bacterial and protozoan NTDs, such as visceral leishmaniasis, or kala-azar, as it is also known. Kala-azar is common in the Indian subcontinent, caused by Leishmania donovani parasites transmitted to humans through sand fly bites. The governments of Bangladesh, India, and Nepal launched an initiative to eliminate kala-azar as a public health problem in the region in 2005, and Nepal was the first to reach the elimination target in its endemic districts in 2013; however, several cases in 2017 meant that elimination was not validated. In this issue of The Lancet Global Health, Kristien Cloots and colleagues used a 10-year repeat survey to investigate the transmission of L donovani in Nepal since the launch of the kala-azar elimination programme, using the serological direct agglutination test. They found that the seroprevalence of L donovani infection was significantly lower in 2016 than in 2006, coinciding with the start of the elimination initiative. The study also shows that this test is potentially useful for monitoring L donovani transmission. This is important because kala-azar surveillance in Nepal currently involves facility-based monitoring of trends in cases, which is dependent on disease awareness among the community and medical staff and can result in under-reporting. The authors conclude that “the eventual success of the elimination initiative will depend on strengthened surveillance in the near future”. Improved surveillance will meant that those living in remote areas with limited access to health services will not be missed. While celebrating important successes in the scale-up of NTD control and elimination programmes, greater access to medicines, and that this group of diseases is no longer neglected as a global health issue, we must keep in mind that many of the 2020 targets are unlikely to be met. NTDs remain a consequence and cause of poverty. As long as socioeconomic and cultural inequities persist, neglected and marginalised populations will remain at risk, trapped in cycles of poverty. A new decade and a new roadmap bring new opportunities to end the suffering of neglected populations. World NTD Day invites us to regroup to #BeatNTDs: For good. For all. For the study on the impact of the kala-azar elimination initiative on L donovani transmission in Nepal see Articles page e237 For the study on the impact of the kala-azar elimination initiative on L donovani transmission in Nepal see Articles page e237