David H. Molyneux

Neglected tropical diseases (NTDs) have become recognised as important health problems facing at least a billion people in the low-income countries and the poorest communities in middle-income countries. WHO plays a leading role in developing strategies to address these diseases, pharmaceutical companies provide drug donations to treat or control the NTDs and many partners from different constituencies have become increasingly committed to their control or elimination. This review looks to the post-2015 agenda and emphasises that despite the progress made over recent years, if the targets established are to be achieved, then not only will additional financial resources be required to up-scale treatments and increase access, but increased applied and operational research will be necessary to address problems and human capacity in NTD skills will need to be strengthened. Continuing advocacy for the relevance of control or elimination of NTDs must be placed in the context of universal health coverage and access to donated essential medicines for the poor as a right. The evidence that investment in NTD interventions are cost-effective and impact not only on health, but also to enhance socio-economic development, must be refined and promulgated. The global burden of disease attributable to NTDs requires reassessment to appropriately define the true burden, while the potential for unexpected events, political, climatic, environmental as well as biological, have the potential to reduce future progress towards the agreed post-2015 targets. NTD progress towards the WHO Roadmap targets and the fulfilment of the World Health Assembly Resolution 66.12 of 2013 demand continued commitment from all partner constituencies when challenges emerge.

The International Commission for the Certification of Dracunculiasis Eradication (ICCDE) met in December to review progress towards eradication. The status of the programme was presented by WHO and The Carter Center, Atlanta. The Commission received reports from international certification teams that Cote d'Ivoire, Niger and Nigeria were free of transmission and should be certified, while four countries, namely Chad, Ethiopia, Mali and South Sudan, remained endemic. The Commission certified that Somalia and South Africa were free of transmission. During 2013, there was a decline of about 78% in the numbers of cases reported in South Sudan. A report of the perplexing dracunculiasis epidemiology in Chad was also discussed, where dogs have been found to be infected with Dracunculus medinensis.

Background: Ivermectin and albendazole are used in annual mass drug administration (MDA) for the lymphatic filariasis elimination programmes in African countries co-endemic for onchocerciasis, but have additional impact on soil transmitted helminths and the ectoparasitic mite which causes scabies. Assessing these collateral impacts at scale is difficult due to the insensitivity of available parasite detection techniques. Methods: The numbers of cases diagnosed with intestinal helminths and scabies and who received prescriptions for treatment were evaluated in 50 health centres in Zanzibar. Records were examined from 2000, prior to the initiation of MDA to 2005, after six rounds of MDA for lymphatic filariasis had taken place. Results: Health centre records showed a consistent decline in the number of cases of intestinal helminths and scabies diagnosed by community health workers in Zanzibar and the number of prescriptions issued across five age groups. A 90-98% decline in soil transmitted helminths and 68-98% decline in scabies infections were recorded. Poisson regression models aggregated to both the island-level and district-level indicated that the decline was statistically significant. Conclusions: The described method of examining health centre records has the potential for use on a large scale, despite limitations, as a rapid method to evaluate the impacts resulting from both lymphatic filariasis and onchocerciasis MDA. This would result in a reduction in the need for parasitological evaluations to determine prevalence and intensity.

Since 2004 there has been an increased recognition of the importance of Neglected Tropical Diseases (NTDs) as impediments to development. These diseases are caused by a variety of infectious agents - viruses, bacteria and parasites - which cause a diversity of clinical conditions throughout the tropics. The World Health Organisation (WHO) has defined seventeen of these conditions as core NTDs. The objectives for the control, elimination or eradication of these conditions have been defined in World Health Assembly resolutions whilst the strategies for the control or elimination of individual diseases have been defined in various WHO documents. Since 2005 there has been a drive for the expanded control of these diseases through an integrated approach of mass drug administration referred to as Preventive Chemotherapy via community-based distribution systems and through schools. This has been made possible by donations from major pharmaceutical companies of quality and efficacious drugs which have a proven track record of safety. As a result of the increased commitment of endemic countries, bilateral donors and non-governmental development organisations, there has been a considerable expansion of mass drug administration. In particular, programmes targeting lymphatic filariasis, onchocerciasis, schistosomiasis, trachoma and soil transmitted helminth infections have expanded to treat 887. 8 million people in 2009. There has been significant progress towards guinea worm eradication, and the control of leprosy and human African trypanosomiasis. This paper responds to what the authors believe are inappropriate criticisms of these programmes and counters accusations of the motives of partners made in recently published papers. We provide a detailed response and update the information on the numbers of global treatments undertaken for NTDs and list the success stories to date.

Despite growing awareness of the importance of controlling neglected tropical diseases as a contribution to poverty alleviation and achieving the Millennium Development Goals, there is a need to up-scale programmes to achieve wider public health benefits. This implementation deficit is attributable to several factors but one often overlooked is the specific difficulty in tackling diseases that involve both people and animals - the zoonoses. A Disease Reference Group on Zoonoses and Marginalised Infectious Diseases (DRG6) was convened by the Special Programme for Research and Training in Tropical Diseases (TDR), a programme executed by the World Health Organization and co-sponsored by UNICEF, UNDP, the World Bank and WHO. The key considerations included: (a) the general lack of reliable quantitative data on their public health burden; (b) the need to evaluate livestock production losses and their additional impacts on health and poverty; (c) the relevance of cross-sectoral issues essential to designing and implementing public health interventions for zoonotic diseases; and (d) identifying priority areas for research and interventions to harness resources most effectively. Beyond disease specific research issues, a set of common macro-priorities and interventions were identified which, if implemented through a more integrated approach by countries, would have a significant impact on human health of the most marginalised populations characteristically dependent on livestock.

Gold standard diagnosis using blood films or skin snips has dimished relevance as mass drug distribution programmes for control of filaria infections expand. The view of 'diagnosis' and its relevance at the individual level has changed, as it has been recognised that the spectrum of programmatic processes (mapping, mass drug interventions, monitoring and evaluation, and surveillance) require different approaches as different questions are asked at each stage. The feasibility and relevance of skin biopsy or blood film examination is challenged when mass drug distribution seeks to treat all eligibles in communities. The need to expand programmes rapidly by identifying the highest risk communities has seen the development of rapid assessment methods, such as rapid epidemiological mapping of onchocerciasis (REMO) and rapid epidemiological assessment (REA) for onchocerciasis, immunochromatographic test (ICT)-based mapping for lymphatic filariasis (LF), and Rapid Assessment Procedure for Loiasis (RAPLOA) for Loa, to reduce the risk of serious adverse events and to guide projects in high-risk communities. As programmes reduce the prevalence through mass drug distribution, more sensitive techniques are required to define endpoints, for LF in particular where the programmatic goal is elimination; for onchocerciasis, sensitive surveillance tools are required particularly in those areas where such risks of recrudescence are high. Whilst much progress has been made in the development and deployment of rapid methods, there are still specific needs for antigen detection in onchocerciasis, whilst standardisation of a panel of tools for LF will allow the definition of endpoint parameters so that countries can decide when mass drug administration (MDA) can be stopped and have a sensitive post-MDA surveillance system.