Management of the diseases
Integrated intervention-centred approaches to management of neglected tropical diseases focus on outreach to poor and marginalised communities through preventive chemotherapy, intensified case management, vector control, veterinary public health as well as safe water, sanitation and hygiene (2, 13). Preventive chemotherapy through mass drug administration refers to distribution of disease-specific medication to individuals in endemic areas, without the need for individual diagnosis, at low cost (between USD 0.30 and USD 0.50 per person treated) (14). It is therefore at the core of programmes that fight neglected tropical diseases.
Box 1 Clinical signs and symptoms associated with neglected tropical diseases (1, 3, 11, 14)
Skin diseases with severe itching, blindness, acute and chronic diarrhoea, anaemia (with potentially severe adverse effects in children and pregnant women), acute and chronic pain, hepatic disease and other end organ damage as well as cancer
Repeated mass drug administration aims at morbidity control as it tends to lead to reduction in the force of infection as well as having the potential to break disease transmission, as seen in programmes on river blindness (onchocerciasis). Mass drug administration programmes are carried out by non-governmental organisations in collaboration with national governments. Guidelines for national control and elimination programmes have been developed by the World Health Organization based on expert opinion. In addition, the Neglected Tropical Diseases Non-Governmental Organisations Network, a group of more than 60 non-governmental organisations, has developed a comprehensive ‘Behaviour, Environment, Social Inclusion and Equity, as well as Treatment and Care’ framework the BEST framework) to facilitate the uptake of this type of holistic and multidisciplinary approach (15).
Overall, progress has been made with regard to the 2020 targets outlined by the World Health Organization in its Roadmap on neglected tropical diseases, including eradication, national/regional elimination and control, see Box 2 (2, 16). This progress has been possible due to strong global partnerships, donations by the pharmaceutical industry, new diagnostic tools, new drug development, commitment by governments to global collaboration and the support of public and private partners (13, 17).
Box 2 WHO Roadmap strategy on control, elimination and eradication of neglected tropical diseases (2, 16).
Dengue fever, Buruli ulcer, cutaneous leishmaniasis, foodborne trematode infections, Taenia solium (neuro)cysticercosis/taeniosis, echinococcosis, soil-transmitted helminthiasis
Lymphatic filariasis, onchocerciasis, leprosy, human African trypanosomiasis, trachoma, schistosomiasis, rabies, Chagas disease, visceral leishmaniasis
Guinea worm, endemic treponematoses (yaws)
Nonetheless, efforts are still largely focused on the diseases for which medication and large-scale treatment options are available, including lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis and trachoma. Zoonotic diseases, such as T. solium (neuro)cysticercosis/taeniosis, do not necessarily benefit from preventive chemotherapy and need a different, even more cross-sectoral approach, including e.g. environmental studies. Despite vaccines and medication for animals being readily available, zoonotic neglected tropical diseases have received less attention and are sometimes referred to as the most neglected among the neglected tropical diseases (18). Advocacy for and investment in both domestic and wild animal health and community livelihood are key to successful control and elimination of zoonotic neglected tropical diseases.
One promising approach to push this agenda forward would be the integration of management of neglected tropical diseases and that of emerging infectious diseases. These groups of diseases share important characteristics, such as their tendency to affect largely underserved populations, their zoonotic nature and the need for vector control, as well as scarcity of point-of-care diagnostics, drugs and vaccines. Thus, strong and resilient health systems with adequate access to health care and universal health coverage as well as a cross-sectoral ‘one-health approach’ combining human, animal and environmental health should be given highest priority (2, 10).