A Research and Development Agenda for the Control and Elimination of Human Helminthiases

Abstract

In this issue of PLoS Neglected Tropical Diseases, the Disease Reference Group on Helminth Infections (DRG4) has put forward a collection of eight reviews that, taken together, outline a compelling research and development agenda for the control and elimination of helminth diseases of humans (http://www.ploscollections.org/helminths [1]–[8]). Emphasis is placed on six major helminth infections: (i) soil-transmitted helminthiasis; (ii) schistosomiasis; (iii) lymphatic filariasis; (iv) onchocerciasis; (v) food-borne trematodiasis; and (vi) cysticercosis/taeniasis. Selection of these helminthiases is justified on multiple grounds. Firstly, as shown in Table 1, more than half of the world's population is at risk of one or several of these helminthiases, and hundreds of millions of people are currently infected. Secondly, consequences of the mainly long-term chronic infection include suffering, stigmatisation, subtle and gross morbidity (e.g., anaemia, limb deformations and blindness), and premature death, hence causing an intolerable global burden [9]–[17]. These features, in turn, exacerbate poverty [18]–[20]. Thirdly, there is growing commitment at all levels—from local communities to politicians, philanthropic organisations, and civil society—to control and eventually eliminate/eradicate the major human helminthiases. Table 1 Helminth Infections Emphasised by DRG4 for Development of a Research Agenda for Control and Elimination. Figure 1 shows that the six helminthiases are at distinctively different stages of control and elimination with geographical idiosyncrasies for some of them [21]. Several helminthiases have been targeted for elimination (e.g., lymphatic filariasis and onchocerciasis in the Americas), and progress made thus far gives hope that this goal can indeed be achieved by 2015 or 2020 if certain conditions are met [14], [21]. For schistosomiasis and soil-transmitted helminthiasis, discussions are escalating to shift the focus from control to elimination [22], [23], and in Africa, the African Programme for Onchocerciasis Control (APOC) is also moving towards this goal [24]. The pivotal role of research, coupled with teaching and training of strong cadres of researchers from endemic settings as essential backbones and platforms to design, implement, and adapt the control and elimination agenda for major helminthiases as well as other tropical diseases, cannot be emphasised enough [25]–[27]. Figure 1 Stages of control/elimination of the six helminthiases emphasised by DRG4. In 2007/2008, the Special Programme for Research and Training in Tropical Diseases (TDR), based at and executed by the World Health Organization (WHO), and co-sponsored by the United Nations Children's Fund (UNICEF), the United Nations Development Programme (UNDP), the World Bank and WHO, initiated a network of disease-specific and thematic reference groups (DRGs/TRGs). DRG4 was particularly prolific, as witnessed in the collection of authoritative reviews presented here. This accompanying editorial summarises the goal, objectives and expected outcomes of the DRGs/TRGs global research “think tank”. Next, light is shed on the composition of DRG4, its mode of operation and its first outputs. It is then argued that PLoS Neglected Tropical Diseases is an appropriate outlet for the studies reviewed and synthesised by DRG4. Indeed, open access to the identified and ranked research priorities by all stakeholders is a major asset and is likely to reinforce the control and elimination agenda of the major helminthiases.