Neglected Tropical Diseases
A Global Health Council Position Paper
Neglected tropical diseases (NTDs) have afflicted humanity for centuries and “disproportionately affect poor and rural populations who lack access to safe water, sanitation, and essential medicines.”1 They blind, disable, disfigure, stigmatize and potentially kill. The burden of NTDs is concentrated in sub-Saharan Africa, Asia and Latin America and the Caribbean, resulting in between 18 and 57 million years of life lost due to premature mortality and disability. This exceeds the burden of tuberculosis, malaria and many childhood diseases, according to some calculations.2,3 About one billion people are currently infected with one or more NTDs; an additional two billion are at risk.4,5
Background NTDs affect the poor disproportionately and are especially prevalent among children and adolescents. They impair physical and cognitive development, cause adverse pregnancy outcomes, and limit adult productivity in the workforce. As a result, NTDs cause billions of dollars in lost wages and economic productivity, all but ensuring that those at risk of infection remain trapped in a cycle of poverty and disease.
Strategies for combating NTDs are not new. Drug donation programs for several NTDs date back to the 1940s, with participation from several major pharmaceutical companies.6-10
The United States continues to be a global leader in supporting NTD control programs and has the opportunity to improve current program implementation and research and development for disease control.13
Product development partnerships (PDPs) emerged in the 1990s as a solution to address low purchasing power of affected populations, the relatively non-existent market for NTD medicines among wealthy countries, and an overall lack of investment in research and development (R&D) by large scale industry. PDPs may accelerate the development of new technologies for use in low- and middle-income countries by leveraging partnerships with governments, academe, industry, and developing countries. Successes to date reducing the burden of leprosy, guinea worm, onchocerciasis, lymphatic filariasis, Chagas’ disease, schistosomiasis and human African trypanosomiasis prove that interventions to combat NTDs are feasible, immediate, visibly powerful and highly cost-effective.11 For the first time in history, through integrated, regional intervention strategies, control and elimination of many of these NTDs is possible.
To eliminate or eradicate diseases targeted in resolutions of the World Health Assembly and regional committees. To reduce significantly the burden of the most common NTDs through current interventions and to achieve optimal coverage. To ensure that interventions with novel approaches are available, promoted and accessible for all NTDs.
In 2006 the United States Agency for International Development created its NTD Control Program to control and eliminate the seven most common NTDs—ascariasis, trichuriasis, hookworm, schistosomiasis, lymphatic filariasis, trachoma, and onchocerciasis. These NTDs make up 90 percent of the disease burden and the U.S. Government recognizes them as the easiest to tackle, using a strategy of mass drug administration, which can be integrated into childhood immunization, HIV/AIDS and/or malaria programs. In 2008, President Bush announced the five-year, US$350 million Neglected Tropical Diseases Initiative, increasing the political awareness for NTDs and taking considerable strides to fight these diseases in a number of high-burden countries.14,15
Research has shown that eliminating NTDs can allow millions to climb out of poverty, particularly by increasing access to education and improving economic performance.
U.S. investments in NTDs also leveraged additional support from other bilateral donors. Following the 2008 G8 meeting in Japan, members committed to control and eliminate several major NTDs by reaching at least 75 percent of people in the most affected countries in Africa, Asia, and Latin America. In the same year, the United Kingdom’s Department for International Development (DFID) announced a £50 million commitment to fight NTDs over the next five years.
The WHO’s Global Plan to Combat Neglected Tropical Diseases, 2008–2015 (Global Plan), outlines a clear policy framework to address a broad range of NTDs, focusing on populations and interventions rather than specific diseases, the use of a quasi-immunization model for preventive chemotherapy, introduction of innovative tools, and a multi-disease, integrated approach.12 The Global Plan outlines specific targets to be met during its time horizon from 2008 through
Most recently, in 2009, President Obama signaled a continued emphasis on NTDs when he unveiled the Global Health Initiative (GHI), a strategy to strengthen health systems and address disease-specific challenges.13 The GHI emphasizes integrated strategies toward the elimination of some NTDs and sets specific targets to measure progress, including reducing the prevalence of seven NTDs by 50 percent among 70 percent of the affected population, contributing to:
The unit cost of drugs for some of the NTDs is as low as US$0.02 and their systematic use can avert future disease burden significantly.
Impact of Prevention and Control Economic productivity. Controlling hookworm alone could improve future wage earnings by up to 43 percent; in Kenya, deworming could raise per capita earning by 30 percent at a cost of only US$0.49.16,17 Lymphatic filariasis causes an estimated US$1.5 billion loss in GNP each year in India.18 Ten million people living with trachoma, the world’s leading cause of preventable blindness, translates into an estimated US$2.9 billion in lost productivity annually.19 Eliminating NTDs will increase worker productivity and, consequently, reduce the drain of billions of dollars from developing economies. Education. NTDs infect over 400 million school-aged children throughout the developing world. Intestinal worms and schistosomiasis compete for nutrients within the human body. In children, this may reduce cognitive development and educational attainment.20 A recent study from Kenya demonstrated that treating intestinal worm infections was the single most cost-effective way to boost school attendance among other school retention strategies.17 In addition, improving access to school-based health interventions will improve opportunities for young girls to stay in school.21 Health systems. Research on health systems demonstrates that NTD control promotes and improves the efficacy of immunizations, vitamin A and bed net distribution, and maternal child health programs.21 For less than a 10 percent add–on cost, combining NTD treatment with current malaria control efforts improves the impact of malaria control efforts by reducing anemia-related morbidity and mortality.22-25 Maternal and child health. Hookworm infection and schistosomiasis both cause anemia—a primary cause of death and disability in developing countries. Both also contribute to impaired development among children, increased maternal and perinatal mortality and reduced productivity among adults.26, 27 Reproductive health. In women, urinary schistosomiasis (S.haematobium) can develop often-irreversible lesions in the vulva, vagina, cervix, and uterus. These lesions create a lasting entry point for HIV; and one study shows that women with urinary schistosomiasis are three times more
likely to contract HIV. Treatment of schistosomiasis in girls and young women can reduce their risk of acquiring HIV, a vital intervention in sub-Saharan Africa where women represent over 60 percent of HIV infections.27-30
Research Needs Research and development (R&D). All NTDs require R&D efforts to improve the effectiveness of existing tools, to respond to the challenge of drug resistance, and to improve prospects for achieving elimination. For some NTDs, like Chagas’ disease, leishmaniasis, sleeping sickness and Buruli ulcer, the R&D needs are more urgent because of the lack of availability of adequate control tools. Vaccine development for high prevalence NTDs also needs to continue. R&D funding is highly focused on HIV/AIDS, tuberculosis and malaria, which received 80 percent of the US$2.5 billion in funding for neglected disease products in 2007.31 Diagnostics. Current elimination strategies for the most common NTDs are dependent on the continued effectiveness of existing drugs such as praziquantel, ivermectin or albendazole. For sustainable elimination strategies, improved diagnostics are needed, along with the development of vaccines or new back-up drugs—especially in the event of drug resistance. Pediatric formulations and further research in treatment combinations and co-formulation of existing drugs are needed. Information systems. In-country data collection needs to be improved, as the burden of NTDs is significantly underestimated in official statistics. Systemizing data collection on these diseases to establish incidence and prevalence is necessary to calculate the real requirements for medicines and laboratory reagents, which in turn will ensure the availability of diagnosis and treatment supplies. Implementation and operations research. Improving programmatic efficiency and effectiveness continues to be a high priority for major global health donors, including the U.S. Government. Further operations research is needed to understand how best to integrate U.S.-supported NTD control and treatment programs with other existing health
Geographic Distribution of NTDs23
NTDs and the Millennium Development Goals With a steady scale-up of funding and a comprehensive approach to prevention, treatment, and research & development of more effective drugs and diagnostics, the U.S. Government, in close collaboration with the international community, has the ability dramatically to decrease the number of people affected by NTDs. Controlling and eliminating many NTDs will help to alleviate poverty, increase the health and well-being of the world’s poor, and enable countries to reach their Millennium Development Goals (MDGs).
Economic Burden Versus Investing in Treatment32 Economic Costs of NTDs
Cost of treatment
752,000 working days lost per year; US$1.2 billion per year in lost productivity in seven countries (Latin America)
US$317 per disability-adjusted life year (DALY) averted by vector control
Almost US$1.3 billion a year in lost productivity
US$5-10 per DALY averted through mass drug administration (MDA) to all 5-7 year olds
Schistosomiasis 45.4 days lost per infected person per year (Phillipines)
US$10-23 per DALY averted through school-based MDA
Nearly all of the MDGs can be addressed positively through the control and elimination of NTDs: MDG 1,eradicating extreme poverty and hunger; MDG 2, universal primary education; MDG 4, reducing child mortality; MDG 5, improving maternal health; and MDG 6, combating HIV/AIDS, malaria and other diseases.
Burden of Neglected Tropical Diseases
Disease Ascariasis (roundworm) Trichuriasis (whipworm) Hookworm Schistosomiasis Lymphatic filariasis Trachoma Dengue fever Onchocerciasis Leishmaniasis Chagas’ disease Leprosy Human African trypanosomiasis *Percentages do not add up to 100 due to rounding. Buruli ulcer
3,000–60,000 3,000–10,000 3,000–65,000 15,000–280,000 <500 <500 — <500 51,000 14,000 —
Total DALYs (thousands) 1,851 1,012 1,092 1,707 5,941 1,334 670 389 1,974 430 194
At Risk (millions) 4,200 3,200 3,200 779 1,300 590 — 90 350 25 —
Cases (millions) 807 604 576 207 120 84 50 37 12 8.5 0.4
Children who are chronically ill from one or several NTDs are not able to attend school regularly. Likewise, children who have to stay home from school to care for a parent blinded by onchocerciasis or trachoma are likely to miss the opportunity to receive an education. Deworming through mass drug administration programs has been proven as the single most cost-effective means to boost school attendance and ensure better access to education.
Positions Unified Strategy
Global health stakeholders should coordinate to achieve agreed-upon goals and objectives for NTD control and to develop a unified strategy to address NTDs not included in current plans.
The NTD strategy should reflect the disease burden in each country and address health systems strengthening, the underlying causes of illness and death, and the needs of poor or marginalized populations.
The NTD strategy should be led by national governments in partnership with other stakeholders and should be responsive to existing structures and capacity.
Higher investment is needed to expand prevention and treatment services, particularly to at-risk populations; funding must also be allocated to research and development; and investments should focus on countries most in need.
International stakeholders need to work together to establish effective partnerships and to promote and sustain long-term commitments to support holistic and integrated NTD strategies and programs.
Recommendations Increase support and ensure global resource commitments for country-led control and elimination efforts for all NTDs, reflecting local disease epidemiology, national health priorities, and programmatic effectiveness and efficiency. Increase U.S. resources for NTDs through the State, Foreign Operations, and Related Programs appropriations and the budgets associated with the Pandemic and All Hazards Preparedness Act of 2006 and the Projects BioShield Act of 2004 for programs to eliminate the seven most common NTDs. This will not only have a positive impact on the health of children, women, people living with HIV, the poorest 1.4 billion people in the world, but will also have a positive impact on international development and U.S. diplomacy more broadly, increasing worker productivity, economic stability, and national security. Provide support for universal access to diagnostics and treatment to vulnerable communities for all NTDs through early and accurate disease detection, expansion of mass drug administration programs (MDAs), vector control strategies and follow-up measures in endemic countries. Prevent the transmission of NTDs and treat children with NTDs early. Children are the most vulnerable cohort for infections relating to many neglected tropical diseases and should be a primary focus of any comprehensive, integrated NTD treatment program. Work through national programs, non-governmental organizations and product development partnerships (PDPs) in country to
ensure country ownership while increasing access to existing treatments. All partner countries should introduce systems of notification, reporting and registering of NTDs as well as ensure that treatment guidelines are updated and that all treatment options are registered in endemic countries. The U.S. Government should support a comprehensive initiative supporting the expansion of MDAs and seeking to combat all NTDs. Utilize existing platforms such as schools and integrate treatment to reduce the burden of NTDs with other health interventions such as maternal and child health, HIV/AIDS, malaria and more. Support needs-based research, development and introduction of new and better treatment and control tools, such as drugs, diagnostics, vaccines and other health technologies, through investments in innovative mechanisms, such as PDPs, prizes and other means, to make these tools available to at-risk populations. Continue to focus efforts on improving country health systems, particularly supply chain management and information systems, to ensure solutions to control and eliminate NTDs are sustainable and can be integrated into other health sector and disease specific programs. Increase and support the political visibility of NTD control and elimination efforts at the United Nations, specifically by supporting calls to include Neglected Tropical Diseases explicitly in Millennium Development Goal 6—reducing infectious disease.
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The Global Health Council would like to acknowledge the collaboration of the NTD Roundtable and its co-chairs, the Global Network for Neglected Tropical Diseases and the Drugs for Neglected Diseases initiative, in the production of this Position Paper.
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