Priority setting and the 'neglected' tropical diseases

Healthcare Policies to Eliminate Neglected Tropical Diseases (NTDs) in India: A Roadmap

The need for systemic healthcare policies to systematically eliminate NTDs globally and in India has been stressed for more than two decades. Yet, the present policies and the research on them do not meet the need. We present an ontological framework, a research roadmap, and a policy brief to address the gap. The ontology clearly, concisely, and comprehensively represents the combinations of diseases, the objectives regarding the diseases, the entities to address them, the outcomes sought, and the potential policy instruments to invoke. The paper explicates the state of the-policies and state of the research on policies to eliminate NTDs in India. It highlights the significant gaps in the diseases covered, balance in the objectives, comprehensiveness of policies, portfolio of outcomes, and involvement of entities. Last, it presents a set of systemic policies congruent with the ontology to systematically address the gaps. The recommendations are aligned with the present research, policies, practices, and recommendations in India and of the WHO, UN agencies, and other similar bodies. The approach can be generalized to provide roadmaps for other countries facing a similar challenge and for other diseases of similar complexity. The roadmaps, with continuous feedback and learning, can help navigate the challenge efficiently and effectively.

Practices in research, surveillance and control of neglected tropical diseases by One Health approaches: A survey targeting scientists from French-speaking countries

One health (OH) approaches have increasingly been used in the last decade in the fight against zoonotic neglected tropical diseases (NTDs). However, descriptions of such collaborations between the human, animal and environmental health sectors are still limited for French-speaking tropical countries. The objective of the current survey was to explore the diversity of OH experiences applied to research, surveillance and control of NTDs by scientists from French-speaking countries, and discuss their constraints and benefits. Six zoonotic NTDs were targeted: echinococcoses, trypanosomiases, leishmaniases, rabies, Taenia solium cysticercosis and leptospiroses. Invitations to fill in an online questionnaire were sent to members of francophone networks on NTDs and other tropical diseases. Results from the questionnaire were discussed during an international workshop in October 2019. The vast majority (98%) of the 171 respondents considered OH approaches relevant although only 64% had implemented them. Among respondents with OH experience, 58% had encountered difficulties mainly related to a lack of knowledge, interest and support for OH approaches by funding agencies, policy-makers, communities and researchers. Silos between disciplines and health sectors were still strong at both scientific and operational levels. Benefits were reported by 94% of respondents with OH experience, including increased intellectual stimulation, stronger collaborations, higher impact and cost-efficiency of interventions. Recommendations for OH uptake included advocacy, capacity-building, dedicated funding, and higher communities' involvement. Improved research coordination by NTD networks, production of combined human-animal health NTD impact indicators, and transversal research projects on diagnostic and reservoirs were also considered essential.

Emerging and re-emerging bacterial zoonoses in Nigeria: current preventive measures and future approaches to intervention

A characteristic of bacterial zoonoses, diseases caused by bacteria that can be transmitted to humans from animals, is a propensity to re-emerge. Several studies demonstrate their ongoing transmission in Nigeria, the most populous country in Africa. However, as local epidemiological data on bacterial zoonoses are inadequate the extent and impact of these infectious diseases is under-reported. Consequently, they are not a targeted priority of national public health policies. This limited recognition is despite indications of their possible roles in the widespread prevalence of non-malarial undifferentiated fever in Nigeria. While a number of animal reservoirs and arthropod vectors have been identified in the transmission routes of these diseases, an escalation of cases of undiagnosed febrile illness highlights the urgent need for a comprehensive assessment of other potential reservoirs, vectors and transmission cycles that may increase the local risk of infection with bacterial zoonoses. Animal health interventions have been proposed as a cost-effective strategy. Here, we present a broad overview of bacterial zoonotic infections of humans in Nigeria in the context of evolving epidemiological patterns. Further, we propose that facilitating the operation of a community-based One Health program is essential to providing the comprehensive epidemiological information that is required to improve prioritization of bacterial zoonoses. This would provide a driver for much needed investment in relevant public health interventions in Africa's most populous country.

Recent development of leucyl-tRNA synthetase inhibitors as antimicrobial agents

Aminoacyl-tRNA synthetases (aaRSs) widely exist in organisms and mediate protein synthesis. Inhibiting these synthetases can lead to the termination of protein synthesis and subsequently achieve antibacterial and antiparasitic purposes. Moreover, the structures of aaRSs found in eukaryotes have considerable structural differences compared to those in prokaryotes, based on which it is possible to develop highly selective inhibitors. Leucyl-tRNA synthetase (LeuRS) with unique synthesis and editing sites is one of 20 kinds of aaRSs. Many inhibitors targeting LeuRS have been designed and synthesized, some of which have entered clinical use. For example, the benzoxaborole compound AN2690 has been approved by the FDA for the treatment of onychomycosis. AN3365 is suspended in the phase II clinical trial due to the rapid development of AN3365 resistance, but it may be used in combination with other antibiotics. The aaRSs, especially LeuRS, are being considered as targets of new potential anti-infective drugs for the treatment of not only bacterial or fungal infections but also infections by trypanosomes and malaria parasites. This review mainly describes the development of LeuRS inhibitors, focusing on their mechanisms of action, structure-activity relationships (SARs), and in vitro and in vivo activities.

Health, financial, and education gains of investing in preventive chemotherapy for schistosomiasis, soil-transmitted helminthiases, and lymphatic filariasis in Madagascar: A modeling study

BACKGROUND

Neglected tropical diseases (NTDs) account for a large disease burden in sub-Saharan Africa. While the general cost-effectiveness of NTD interventions to improve health outcomes has been assessed, few studies have also accounted for the financial and education gains of investing in NTD control.

METHODS

We built on extended cost-effectiveness analysis (ECEA) methods to assess the health gains (e.g. infections, disability-adjusted life years or DALYs averted), household financial gains (out-of-pocket expenditures averted), and education gains (cases of school absenteeism averted) for five NTD interventions that the government of Madagascar aims to roll out nationally. The five NTDs considered were schistosomiasis, lymphatic filariasis, and three soil-transmitted helminthiases (Ascaris lumbricoides, Trichuris trichiura, and hookworm infections).

RESULTS

The estimated incremental cost-effectiveness for the roll-out of preventive chemotherapy for all NTDs jointly was USD125 per DALY averted (95% uncertainty range: 65-231), and its benefit-cost ratio could vary between 5 and 31. Our analysis estimated that, per dollar spent, schistosomiasis preventive chemotherapy, in particular, could avert a large number of infections (176,000 infections averted per $100,000 spent), DALYs (2,000 averted per $100,000 spent), and cases of school absenteeism (27,000 school years gained per $100,000 spent).

CONCLUSION

This analysis incorporates financial and education gains into the economic evaluation of health interventions, and therefore provides information about the efficiency of attainment of three Sustainable Development Goals (SDGs). Our findings reveal how the national scale-up of NTD control in Madagascar can help address health (SDG3), economic (SDG1), and education (SDG4) goals. This study further highlights the potentially large societal benefits of investing in NTD control in low-resource settings.

Equity and efficiency in the scaled-up implementation of integrated neglected tropical disease control: the health economics protocol of the COUNTDOWN multicountry observational study in Ghana, Cameroon and Liberia

INTRODUCTION

Worldwide, millions of individuals are affected by neglected tropical diseases (NTDs). They are frequently the poorest and most marginalised members of society. Their living conditions, among other things, make them susceptible to such diseases. Historically, several large-scale treatment programmes providing mass drug administrations (MDAs) were carried out per single disease but over the last decade there has been an increasing trend towards co-implementation of MDA activities given the resources used for such programmes are often the same. The COUNTDOWN multicountry studies focus on scaled-up implementation of integrated control strategies against four diseases: lymphatic filariasis, onchocerciasis, schistosomiasis and soil-transmitted helminthiasis. The objective of the COUNTDOWN economic study is to assess the multicountry implementation of control interventions in terms of equity, impact and efficiency.

METHODS

The health economic study uses different analytical methods to assess the relationship between NTDs and poverty and the cost-effectiveness of different large-scale intervention options. Regression analysis will be used to study the determinants of NTD occurrence, the impact of NTDs on poverty, factors that hinder access to MDAs and the effect of NTDs on quality-of-life of those affected, including disability. Cost-effectiveness analyses of various integration methods will be performed using health economic modelling to estimate the cost and programme impact of different integration options. Here, cost-effectiveness ratios will be calculated, including multivariate sensitivity analyses, using Bayesian analysis.

ETHICS AND DISSEMINATION

Ethics approval has been received both at the Liverpool School of Tropical Medicine and in all participating countries. Results of the various substudies will be presented for publication in peer-reviewed journals.

STUDY DATES

1 July 2016 to 30 June-October 2019.

The cross-cutting contribution of the end of neglected tropical diseases to the sustainable development goals

The Sustainable Development Goals (SDGs) call for an integrated response, the kind that has defined Neglected Tropical Diseases (NTDs) efforts in the past decade.NTD interventions have the greatest relevance for SDG3, the health goal, where the focus on equity, and its commitment to reaching people in need of health services, wherever they may live and whatever their circumstances, is fundamentally aligned with the target of Universal Health Coverage. NTD interventions, however, also affect and are affected by many of the other development areas covered under the 2030 Agenda. Strategies such as mass drug administration or the programmatic integration of NTD and WASH activities (SDG6) are driven by effective global partnerships (SDG17). Intervention against the NTDs can also have an impact on poverty (SDG1) and hunger (SDG2), can improve education (SDG4), work and economic growth (SDG8), thereby reducing inequalities (SDG10). The community-led distribution of donated medicines to more than 1 billion people reinforces women's empowerment (SDG5), logistics infrastructure (SDG9) and non-discrimination against disability (SDG16). Interventions to curb mosquito-borne NTDs contribute to the goals of urban sustainability (SDG11) and resilience to climate change (SDG13), while the safe use of insecticides supports the goal of sustainable ecosystems (SDG15). Although indirectly, interventions to control water- and animal-related NTDs can facilitate the goals of small-scale fishing (SDG14) and sustainable hydroelectricity and biofuels (SDG7).NTDs proliferate in less developed areas in countries across the income spectrum, areas where large numbers of people have little or no access to adequate health care, clean water, sanitation, housing, education, transport and information. This scoping review assesses how in this context, ending the epidemic of the NTDs can impact and improve our prospects of attaining the SDGs.

The Burden of Zoonoses in Kyrgyzstan: A Systematic Review

INTRODUCTION

Zoonotic disease (ZD) pose a serious threat to human health in low-income countries. In these countries the human burden of disease is often underestimated due to insufficient monitoring because of insufficient funding. Quantification of the impact of zoonoses helps in prioritizing healthcare needs. Kyrgyzstan is a poor, mountainous country with 48% of the population employed in agriculture and one third of the population living below the poverty line.

METHODOLOGY/PRINCIPAL FINDINGS

We have assessed the burden of zoonoses in Kyrgyzstan by conducting a systematic review. We have used the collected data to estimate the burden of ZDs and addressed the underestimation in officially reported disease incidence. The estimated incidences of the ZDs were used to calculate incidence-based Disability Adjusted Life Years (DALYs). This standardized health gap measure enhances comparability between injuries and diseases. The combined burden for alveolar echinococcosis, cystic echinococcosis, brucellosis, campylobacteriosis, congenital toxoplasmosis, non-typhoidal salmonellosis and rabies in Kyrgyzstan in 2013 was 35,209 DALYs [95% Uncertainty interval (UI):13,413-83,777]; 576 deaths [95% UI: 279-1,168] were attributed to these infections. We estimate a combined median incidence of ZDs of 141,583 cases [95% UI: 33,912-250,924] in 2013. The highest burden was caused by non-typhoidal Salmonella and Echinococcus multilocularis, respectively 14,792 DALYs [95% UI: 3,966-41,532] and 11,915 DALYs [95% UI: 4,705-27,114] per year.

CONCLUSION/SIGNIFICANCE

The health impact of zoonoses in Kyrgyzstan is substantial, comparable to that of HIV. Community-based surveillance studies and hospital-based registration of all occurrences of zoonoses would increase the accuracy of the estimates.

Identifying gaps in research prioritization: The global burden of neglected tropical diseases as reflected in the Cochrane database of systematic reviews

Background:

Neglected tropical diseases (NTDs) impact disadvantaged populations in resource-scarce settings. Availability of synthesized evidence is paramount to end this disparity. The aim of the study was to determine whether NTD systematic reviews or protocols in the Cochrane Database of Systematic Reviews (CDSR) reflect disease burden.

Methods:

Two authors independently searched the CDSR for reviews/protocols regarding the NTDs diseases. Each review or protocol was classified to a single NTD category. Any discrepancy was solved by consensus with third author. NTD systematic review or protocol from CDSR were matched with disability-adjusted life year (DALY) metrics from the Global Burden of Disease 2010 Study. Spearman's rank correlation coefficient and associated P values were used to assess for correlation between the number of systematic reviews and protocols and the %2010 DALY associated with each NTD.

Results:

Overall, there was poor correlation between CDSR representation and DALYs. Yellow fever, echinococcus, onchocerciasis, and schistosomiasis representation was well-aligned with DALY. Leprosy, trachoma, dengue, leishmaniasis, and Chagas disease representation was greater, while cysticercosis, human African trypanosomiasis, ascariasis, lymphatic filariasis, and hookworm representation was lower than DALY. Three of the 18 NTDs had reviews/protocols of diagnostic test accuracy.

Conclusions:

Our results indicate the need for increased prioritization of systematic reviews on NTDs, particularly diagnostic test accuracy reviews.

In the shadowlands of global health: observations from health workers in Kenya

During the past decade, donor funding for health interventions in Kenya and other African countries has risen sharply. Focused on high-profile diseases such as HIV/AIDS, these funds create islands of intervention in a sea of under-resourced public health services. This paper draws on ethnographic research conducted in HIV clinics and in a public hospital to examine how health workers experience and reflect upon the juxtaposition of ‘global’ medicine with ‘local’ medicine. We show that health workers face an uneven playing field. High-prestige jobs are available in HIV research and treatment, funded by donors, while other diseases and health issues receive less attention. Outside HIV clinics, patient's access to medicines and laboratory tests is expensive, and diagnostic equipment is unreliable. Clinicians must tailor their decisions about treatment to the available medical technologies, medicines and resources. How do health workers reflect on working in these environments and how do their experiences influence professional ambitions and commitments?

Emerging and reemerging neglected tropical diseases: a review of key characteristics, risk factors, and the policy and innovation environment

In global health, critical challenges have arisen from infectious diseases, including the emergence and reemergence of old and new infectious diseases. Emergence and reemergence are accelerated by rapid human development, including numerous changes in demographics, populations, and the environment. This has also led to zoonoses in the changing human-animal ecosystem, which are impacted by a growing globalized society where pathogens do not recognize geopolitical borders. Within this context, neglected tropical infectious diseases have historically lacked adequate attention in international public health efforts, leading to insufficient prevention and treatment options. This subset of 17 infectious tropical diseases disproportionately impacts the world's poorest, represents a significant and underappreciated global disease burden, and is a major barrier to development efforts to alleviate poverty and improve human health. Neglected tropical diseases that are also categorized as emerging or reemerging infectious diseases are an even more serious threat and have not been adequately examined or discussed in terms of their unique risk characteristics. This review sets out to identify emerging and reemerging neglected tropical diseases and explore the policy and innovation environment that could hamper or enable control efforts. Through this examination, we hope to raise awareness and guide potential approaches to addressing this global health concern.

Tackling the existing burden of infectious diseases in the developing world: existing gaps and the way forward

This series evaluates the effectiveness of community-based interventions (CBIs) to prevent and control infectious diseases of poverty (IDoP). Evidence from our reviews suggests that CBIs and school-based delivery platforms are effective in averting risk behaviors and reducing the disease burden. Co-implementation of interventions through existing community-based programs including immunization campaigns, antenatal care and maternal and child health programs have the potential to scale-up interventions for IDoP. Future research should focus on the process of developing and implementing efficient community-based programs through a comprehensive approach, and to gauge the effectiveness of various existing delivery models in order to improve morbidity and mortality outcomes.

Official development assistance for health-how neglected are neglected tropical diseases? An analysis of health financing

The increasing amounts of official development assistance (ODA) for health have been aimed primarily at fighting HIV/AIDS, malaria and tuberculosis. Neglected tropical diseases (NTD), one of the most serious public health burdens among the most deprived communities, have only recently drawn the attention of major donors. While frequently stated, the low share of funding for NTD control projects has not been calculated empirically. Our analysis of ODA commitments for infectious disease control for the years 2003 to 2007 confirms that Development Assistance Committee (DAC)-countries and multilateral donors have largely ignored funding NTD control projects. On average, only 0.6% of total annual health ODA was dedicated to the fight against NTDs while the average share of control projects for HIV/AIDS was 36.3%, for malaria 3.6%, and for tuberculosis 2.2%. This allocation of health ODA does not reflect the diseases' respective health burdens. Furthermore, the availability of cost-efficient treatments for NTDs supports the call for an increase in funds dedicated to the control of NTDs.

Disease control priorities for neglected tropical diseases: lessons from priority ranking based on the quality of evidence, cost effectiveness, severity of disease, catastrophic health expenditures, and loss of productivity

BACKGROUND

In the context of limited health care budgets in countries where Neglected Tropical Diseases (NTDs) are endemic, scaling up disease control interventions entails the setting of priorities. However, solutions based solely on cost-effectiveness analyses may lead to biased and insufficiently justified priorities.

OBJECTIVES

The objectives of this paper are to 1) demonstrate how a range of equity concerns can be used to identify feasible priority setting criteria, 2) show how these criteria can be fed into a multi-criteria decision-making matrix, and 3) discuss the conditions under which this decision-making procedure should be carried out in a real-world decision-making context.

METHODS

This paper draws on elements from theories of decision analysis and ethical theories of fair resource allocation. We explore six typical NTD interventions by employing a modified multi-criteria decision analysis model with predefined criteria, drawn from a priority setting guide under development by the WHO. To identify relevant evidence for the six chosen interventions, we searched the PubMed and Cochrane databases.

DISCUSSION

Our in vitro multi-criteria decision analysis suggested that case management for visceral leishmaniasis should be given a higher priority than mass campaigns to prevent soil-transmitted helminthic infections. This seems to contradict current health care priorities and recommendations in the literature. We also consider procedural conditions that should be met in a contextualised decision-making process and we stress the limitations of this study exercise.

CONCLUSION

By exploring how several criteria relevant to the multi-facetted characteristics of NTDs can be taken into account simultaneously, we are able to suggest how improved priority settings among NTDs can be realised.

A research agenda for helminth diseases of humans: the problem of helminthiases

A disproportionate burden of helminthiases in human populations occurs in marginalised, low-income, and resource-constrained regions of the world, with over 1 billion people in developing areas of sub-Saharan Africa, Asia, and the Americas infected with one or more helminth species. The morbidity caused by such infections imposes a substantial burden of disease, contributing to a vicious circle of infection, poverty, decreased productivity, and inadequate socioeconomic development. Furthermore, helminth infection accentuates the morbidity of malaria and HIV/AIDS, and impairs vaccine efficacy. Polyparasitism is the norm in these populations, and infections tend to be persistent. Hence, there is a great need to reduce morbidity caused by helminth infections. However, major deficiencies exist in diagnostics and interventions, including vector control, drugs, and vaccines. Overcoming these deficiencies is hampered by major gaps in knowledge of helminth biology and transmission dynamics, platforms from which to help develop such tools. The Disease Reference Group on Helminths Infections (DRG4), established in 2009 by the Special Programme for Research and Training in Tropical Diseases (TDR), was given the mandate to review helminthiases research and identify research priorities and gaps. In this review, we provide an overview of the forces driving the persistence of helminthiases as a public health problem despite the many control initiatives that have been put in place; identify the main obstacles that impede progress towards their control and elimination; and discuss recent advances, opportunities, and challenges for the understanding of the biology, epidemiology, and control of these infections. The helminth infections that will be discussed include: onchocerciasis, lymphatic filariasis, soil-transmitted helminthiases, schistosomiasis, food-borne trematodiases, and taeniasis/cysticercosis.

Schistosomiasis and soil-transmitted helminth control in Niger: cost effectiveness of school based and community distributed mass drug administration [corrected]

BACKGROUND

In 2004 Niger established a large scale schistosomiasis and soil-transmitted helminths control programme targeting children aged 5-14 years and adults. In two years 4.3 million treatments were delivered in 40 districts using school based and community distribution.

METHOD AND FINDINGS

Four districts were surveyed in 2006 to estimate the economic cost per district, per treatment and per schistosomiasis infection averted. The study compares the costs of treatment at start up and in a subsequent year, identifies the allocation of costs by activity, input and organisation, and assesses the cost of treatment. The cost of delivery provided by teachers is compared to cost of delivery by community distributers (CDD). The total economic cost of the programme including programmatic, national and local government costs and international support in four study districts, over two years, was US$ 456,718; an economic cost/treatment of $0.58. The full economic delivery cost of school based treatment in 2005/06 was $0.76, and for community distribution was $0.46. Including only the programme costs the figures are $0.47 and $0.41 respectively. Differences at sub-district are more marked. This is partly explained by the fact that a CDD treats 5.8 people for every one treated in school. The range in cost effectiveness for both direct and direct and indirect treatments is quantified and the need to develop and refine such estimates is emphasised.

CONCLUSIONS

The relative cost effectiveness of school and community delivery differs by country according to the composition of the population treated, the numbers targeted and treated at school and in the community, the cost and frequency of training teachers and CDDs. Options analysis of technical and implementation alternatives including a financial analysis should form part of the programme design process.

Health metrics for helminthic infections

Over the past five decades, accurate and comparable assessment of disease burden due to different 'worm' infections has proven problematic. Estimates of the health impact of helminths have varied significantly, depending on the assessor's perspective and the approaches taken to quantifying disease effects on patient performance status. Past surveys have frequently suffered from misclassification bias due to the lack of a diagnostic 'gold' standard. At the same time, there has been a tendency to define disease based solely on late-onset, 'pathognomonic' outcomes that can be uniquely attributed to each pathogen. However, we are now gaining a much better understanding of the role of helminths in anaemia causation, impaired growth and development, and poor school or work performance. With a new appreciation of the link between long-term, parasite-mediated inflammation and the patient's lifetime risk of disability, we recognise that the bulk of worm-associated diseases is found in the latter, 'non-specific' categories, with relevance to individual performance status and detriment to regional levels of human capital. Appropriately, the emerging use of comprehensive disability metrics such as the quality-adjusted life year (QALY)-as opposed to the widely used disability-adjusted life year (DALY) metrics-will better capture the impact of helminthic infections on the long-term health of Asian and other developing world populations. This improved, more valid assessment is expected to provide evidence favouring preventive over curative intervention for control of these highly prevalent diseases.

Eradication of Taenia solium cysticercosis: a role for vaccination of pigs

Taenia solium is the causative agent of neurocysticercosis, a disease responsible for substantial human morbidity and mortality. It is a zoonotic parasite, involving pigs as intermediate hosts. The parasite's full life cycle is restricted to poor people in developing countries. Attempts to date to control transmission of the parasite have been relatively poorly effective and not sustainable. Over the past decade research has been undertaken to develop practical vaccines for use in pigs to prevent transmission of T. solium. The most effective of these vaccines in controlled experimental trials has been the TSOL18 vaccine. More recently, TSOL18 has been proven to be highly effective against naturally acquired infection with T. solium in pigs. Application of TSOL18 together with a single treatment of pigs with oxfendazole achieved the complete elimination of transmission of the parasite by pigs involved in the field trial. This strategy may provide a relatively low cost and sustainable control tool which could assist towards the goal of achieving eradication of the parasite. An assessment is made of the potential value of various control measures that are available for T. solium, and two options are suggested as potential parasite control programs.

Socioeconomic aspects of neglected tropical diseases

Although many examples of highly cost-effective interventions to control neglected tropical diseases exist, our understanding of the full economic effect that these diseases have on individuals, households, and nations needs to be improved to target interventions more effectively and equitably. We review data for the effect of neglected tropical diseases on a population's health and economy. We also present evidence on the costs, cost-effectiveness, and financing of strategies to monitor, control, or reduce morbidity and mortality associated with these diseases. We explore the potential for economies of scale and scope in terms of the costs and benefits of successfully delivering large-scale and integrated interventions. The low cost of neglected tropical disease control is driven by four factors: the commitment of pharmaceutical companies to provide free drugs; the scale of programmes; the opportunities for synergising delivery modes; and the often non-remunerated volunteer contribution of communities and teachers in drug distribution. Finally, we make suggestions for future economic research.

Integration of control of neglected tropical diseases into health-care systems: challenges and opportunities

Although progress has been made in the fight against neglected tropical diseases, current financial resources and global political commitments are insufficient to reach the World Health Assembly's ambitious goals. Increased efforts are needed to expand global coverage. These efforts will involve national and international harmonisation and coordination of the activities of partnerships devoted to control or elimination of these diseases. Rational planning and integration into regular health systems is essential to scale up these interventions to achieve complete eradication of these diseases. Programmes with similar delivery strategies and interventions-such as those for onchocerciasis, lymphatic filariasis, and soil-transmitted helminthiasis-could be managed on the same platform and together. Furthermore, better-resourced programmes-such as those for malaria, HIV/AIDS, and tuberculosis-could work closely with those for neglected tropical diseases to their mutual benefit and the benefit of the entire health system.

Neglected and endemic zoonoses

Endemic zoonoses are found throughout the developing world, wherever people live in close proximity to their animals, affecting not only the health of poor people but often also their livelihoods through the health of their livestock. Unlike newly emerging zoonoses that attract the attention of the developed world, these endemic zoonoses are by comparison neglected. This is, in part, a consequence of under-reporting, resulting in underestimation of their global burden, which in turn artificially downgrades their importance in the eyes of administrators and funding agencies. The development of cheap and effective vaccines is no guarantee that these endemic diseases will be eliminated in the near future. However, simply increasing awareness about their causes and how they may be prevented-often with very simple technologies-could reduce the incidence of many endemic zoonoses. Sustainable control of zoonoses is reliant on surveillance, but, as with other public-sector animal health services, this is rarely implemented in the developing world, not least because of the lack of sufficiently cheap diagnostics. Public-private partnerships have already provided advocacy for human disease control and could be equally effective in addressing endemic zoonoses.

Promoting effective interventions for neglected health conditions in developing countries

The United Nations' millennium development project has set global priorities for the mobilization and allocation of resources to the developing world until 2015. However, many health conditions are currently excluded from this global marshal plan and may remain so for the next decade because they do not satisfy the conventional criteria for high priority status. This paper presents an example of how indigenous private-public partnerships can play an effective role in stimulating national initiatives for health interventions for neglected but significant conditions where government capacity or external donor support is limited or lacking.

On the extent and origins of genic novelty in the phylum Nematoda

BACKGROUND

The phylum Nematoda is biologically diverse, including parasites of plants and animals as well as free-living taxa. Underpinning this diversity will be commensurate diversity in expressed genes, including gene sets associated specifically with evolution of parasitism.

METHODS AND FINDINGS

Here we have analyzed the extensive expressed sequence tag data (available for 37 nematode species, most of which are parasites) and define over 120,000 distinct putative genes from which we have derived robust protein translations. Combined with the complete proteomes of Caenorhabditis elegans and Caenorhabditis briggsae, these proteins have been grouped into 65,000 protein families that in turn contain 40,000 distinct protein domains. We have mapped the occurrence of domains and families across the Nematoda and compared the nematode data to that available for other phyla. Gene loss is common, and in particular we identify nearly 5,000 genes that may have been lost from the lineage leading to the model nematode C. elegans. We find a preponderance of novelty, including 56,000 nematode-restricted protein families and 26,000 nematode-restricted domains. Mapping of the latest time-of-origin of these new families and domains across the nematode phylogeny revealed ongoing evolution of novelty. A number of genes from parasitic species had signatures of horizontal transfer from their host organisms, and parasitic species had a greater proportion of novel, secreted proteins than did free-living ones.

CONCLUSIONS

These classes of genes may underpin parasitic phenotypes, and thus may be targets for development of effective control measures.

The health impact of polyparasitism in humans: are we under-estimating the burden of parasitic diseases?

Parasitic infections are widespread throughout the tropics and sub-tropics, and infection with multiple parasite species is the norm rather than the exception. Despite the ubiquity of polyparasitism, its public health significance has been inadequately studied. Here we review available studies investigating the nutritional and pathological consequences of multiple infections with Plasmodium and helminth infection and, in doing so, encourage a reassessment of the disease burden caused by polyparasitism. The available evidence is conspicuously sparse but is suggestive that multiple human parasite species may have an additive and/or multiplicative impact on nutrition and organ pathology. Existing studies suffer from a number of methodological limitations and adequately designed studies are clearly necessary. Current methods of estimating the potential global morbidity due to parasitic diseases underestimate the health impact of polyparasitism, and possible reasons for this are presented. As international strategies to control multiple parasite species are rolled-out, there is a number of options to investigate the complexity of polyparasitism, and it is hoped that that the parasitological research community will grasp the opportunity to understand better the health of polyparasitism in humans.

Recent progress in integrated neglected tropical disease control

Three years have passed since the publication of the first of a series of policy papers, which first highlighted the under-appreciated global burden of the neglected tropical diseases (NTDs) and then outlined a rationale for linking vertical control strategies for the seven most prevalent NTDs in a cost-effective pro-poor package of preventive chemotherapy. Since then, global advocacy for these conditions has increased and, with it, new funds for scale-up of integrated NTD control in sub-Saharan Africa. Recent speeches by the Director General of the World Health Organization at regional meetings have referred to NTDs as important global health priorities (www.who.int/dg/speeches/2007). Outlined here is a summary of the recent progress in global efforts to integrate NTD control, with an emphasis on the challenges that lie ahead.

Parasites, people and policy: infectious diseases and the Millennium Development Goals

Here, I briefly review past history and present patterns in the interactions between parasites (defined broadly to include viruses and bacteria along with protozoan, helminth and arthropod parasites) and human populations in developed and developing countries. Against this background, I offer thoughts on current public health initiatives at national and international levels, with particular reference to the Millennium Development Goals. The news is both good and bad: mortality and morbidity from infectious diseases in the developing world are significantly lower than they were 50 years ago, but we should and could be doing better, particularly in relation to neglected tropical diseases.

The antipoverty vaccines

The neglected tropical diseases represent a group of parasitic and bacterial diseases, occurring primarily in rural areas or impoverished urban areas of developing countries. Because of their chronic and stigmatizing character and their impact on child development, pregnancy outcomes, and worker productivity, the neglected tropical diseases are considered poverty-promoting conditions. Through the activities of public-private partnerships, first or second-generation recombinant vaccines for three of these conditions--hookworm, leishmaniasis, and schistosomiasis, have undergone early development and clinical testing. However, through the acquisition of extensive bioinformatics information or animal model testing for several other neglected tropical diseases pathogens, it is possible to consider new generation vaccines as well for amebiasis, Buruli ulcer, Chagas disease, Chlamydia infections (including trachoma), leprosy, leptospirosis, and the treponematoses. Early development of such antipoverty vaccines will require the establishment of product development public-private partnerships and partnerships with innovative developing countries where these diseases are endemic.