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Keywords:

  • neglected diseases;
  • poverty;
  • neglected tropical diseases;
  • intersectorial;
  • intersectoral;
  • Millennium Development Goals;
  • Latin America and Caribbean;
  • slum;
  • rural;
  • indigenous

Abstract

  1. Top of page
  2. Abstract
  3. Neglected Diseases Linked to Poverty, Governance, and Security
  4. Current Interventions for Control of Neglected Diseases
  5. Prevention and Control of Neglected Diseases: A Multisectoral Problem
  6. Intersectoral Action to Combat Neglected Diseases and Poverty
  7. Acknowledgments
  8. Conflicts of Interest
  9. References

The neglected diseases are a diverse group of communicable diseases that affect principally the world's poorest people. They are linked to poverty, as both a cause and a consequence of same, and affect community security and family productivity. The neglected diseases cause acute and chronic illness, disability, and sometimes death, and they may carry stigma for those infected. Current interventions for neglected diseases emphasize the health sector, but to achieve sustainability and simultaneously combat poverty, an intersectoral approach to their prevention and control is needed. This chapter outlines some concepts for an intersectoral approach, including interventions from the nutrition and food security, education, and environmental sectors.

The neglected diseases (NDs), sometimes referred to as neglected tropical diseases, are a group of infectious diseases found principally in poor or marginalized communities (e.g., the rural poor, the urban poor and slum dwellers, indigenous groups) in the tropics, subtropics, and in parts of North America1 and other temperate zones both historically and contemporarily (whether imported or autochthonous cases). Globally, they affect more than 1 billion people and put at least 2 billion at risk, or nearly one in three persons on the planet. The World Health Organization (WHO) has identified a group of 13 of these NDs that are among the most common infections in many of the poorest communities globally.2 They include parasitic and bacterial diseases or conditions that disable or debilitate, such as lymphatic filariasis, leprosy, leishmaniasis, and schistosomiasis; those that cause anemia and adversely affect physical growth and development, such as soil-transmitted helminthiasis (STH; ascariasis, trichuriasis, and hookworm infection); those that can cause blindness, such as onchocerciasis and trachoma; and parasitic zoonoses often transmitted as part of the human food consumption chain.3 Other important NDs in some poor communities include dengue, skin diseases or conditions caused by bacteria (e.g., Buruli ulcer, yaws), superficial fungi, ectoparasites (scabies mites; “sand fleas” causing tungiasis), and myiasis-causing flies. Some NDs, such as schistosomiasis, visceral leishmaniasis, human African trypanosomiasis (HAT), and Chagas, disease, may also cause death.

Neglected Diseases Linked to Poverty, Governance, and Security

  1. Top of page
  2. Abstract
  3. Neglected Diseases Linked to Poverty, Governance, and Security
  4. Current Interventions for Control of Neglected Diseases
  5. Prevention and Control of Neglected Diseases: A Multisectoral Problem
  6. Intersectoral Action to Combat Neglected Diseases and Poverty
  7. Acknowledgments
  8. Conflicts of Interest
  9. References

The NDs as a group contribute, directly or indirectly, to global poverty and insecurity. In poor tropical countries, where they are principally found, they contribute indirectly to poverty and to social and physical insecurity, which is the root of much social discontent and civil unrest. They also contribute directly to economic insecurity (victims unable to work or work full-time), food insecurity (individuals disabled or chronically ill, preventing the generation of sufficient family income), and social ostracization (the stigma of leprosy, filarial lymphoedema, and hydrocele).4

The NDs are both a cause and a consequence of poverty, and they are exemplified by STH, intestinal infections that commonly infect from 25% to 100% of poor communities—particularly the more vulnerable members, such as children and pregnant women. Hotez,5 in another chapter of this special issue, describes the connections between one STH, the hookworm infections, and poverty.

These diseases are characterized in part by little public investment in surveillance, treatment, and prevention. The NDs represent a governance challenge when and where government health services do not reach the poor and marginalized, and they contribute to disenfranchisement and even resentment when treatment is not available; this is ironic in that basic treatment for several NDs, such as preventive chemotherapy for STHs, is neither expensive nor complicated and treatment is cost-effective. Indeed, the principal medicines to treat NDs are often donated by pharmaceutical companies and foundations through global alliances and by the WHO to countries (e.g., for leprosy, lymphatic filariasis, onchocerciasis, trachoma, and in some countries schistosomiasis). These public–private partnerships (PPPs) are keys to the sustainable control and, sometimes, elimination of certain NDs as public health problems by simply improving access of the poorest to needed medicines. Other PPPs are pursuing product development research into new drugs and vaccines to treat or prevent NDs.

The STHs contribute to poor school attendance and test performance, thus limiting the chances of successful completion of schooling and the chance for better employment. Intestinal helminthiasis and schistosomiasis contribute significantly to anemia in children and young adults, limiting the ability of the latter to do physical labor and thus reducing their income potential, especially in agrarian and rural societies. The NDs contribute directly to economic insecurity in creating limited access to schooling as a result of stigma (leprosy, leishmaniasis, anthrax). The stigma surrounding leprosy and lymphatic filariasis contributes to the lack of interest of some health officials who themselves do not well understand this group of diseases, and as a result entire families or communities can be ostracized or estranged from access to both health services and employment. Finally, some NDs, such as the STHs and tapeworms, contribute directly to food insecurity by causing iron-deficiency anemia (especially where there is coinfection with malaria) or by direct consumption of micronutrients and calories that the infected host (be they child, adolescent, mother, or worker) would otherwise benefit from.

Current Interventions for Control of Neglected Diseases

  1. Top of page
  2. Abstract
  3. Neglected Diseases Linked to Poverty, Governance, and Security
  4. Current Interventions for Control of Neglected Diseases
  5. Prevention and Control of Neglected Diseases: A Multisectoral Problem
  6. Intersectoral Action to Combat Neglected Diseases and Poverty
  7. Acknowledgments
  8. Conflicts of Interest
  9. References

Several of the NDs have been the subject of vertical control programs since at least the 1950s through the 1980s (e.g., the vectorborne NDs, such as malaria and onchocerciasis in tropical West Africa, which relied principally on insecticide application). Today vectorborne ND control managers are expected to benefit from a new emphasis on integrated vector management built on three decades of field research and operational experience. New medicines and long-lasting insecticide–treated bed nets for malaria and new delivery systems, such as community-directed treatment for onchocerciasis, have greatly changed the choice of interventions. Leprosy, or Hansen disease, had historically been managed through leprosaria with patient isolation and warehousing compounded by stigmatism and sometimes abuse. Only in about last two decades has leprosy treatment emerged from this historic model to one of a more integrated and patient-focused approach involving treatment, prevention of disabilities, and rehabilitation conducted in public health clinics or home and community settings—the result of epidemiological research yielding improved understanding of the risks of transmission, the advent of new and effective multidrug therapy, and, more recently, the work of social scientists and patient advocates to combat social stigma and promote prevention and rehabilitation.

In this decade several researchers, national public health managers, WHO staff, pharmaceutical companies, and other partners in the Global Network for Neglected Tropical Diseases have contributed to the published WHO guidelines for preventive chemotherapy for human helminthiasis.6 Hotez et al. have described the current set of primary interventions and weaknesses of the current approaches for control of the most prevalent NDs.2 The interventions are primarily preventive chemotherapy (safe drug-based, single-dose medicines) for the STHs, lymphatic filariasis, schistosomiasis, and onchocerciasis, which are often donated to the poorest countries. Other NDs are currently treated with drug combinations (leprosy, HAT), surgical care and antibiotic applications (trachoma, Buruli ulcer), and other interventions ranging from case detection and management (HAT) to vector control (Chagas, disease) and provision of safe water and water filters (dracunculiasis).2 Preventive chemotherapy with the single-dose drugs albendazole, praziquantel, and ivermectin was used to simultaneously treat populations coinfected with STH, schistosomiasis, and lymphatic filariasis, and this drug combination was safe and feasible in children and adults in Zanzibar7; it represents an integrated approach to preventive chemotherapy.

Most of the current interventions described earlier, including integrated preventive chemotherapy, such as applied in Zanzibar, are usually conducted by the health sector and are considered health sector interventions led by ministries of health (sometimes with support from nongovernmental organizations and other partners). However, even if the evidence base is strong, where ministries of health have a shortage of human resources, a lack of information, and weak or absent geographic coverage in the poorest communities (often the case), the sustainability of health-sector interventions for the long-term sustainable control of NDs alone appears not to be clear at this point. This situation suggests that these new interventions, whether integrated or not, will need to be accompanied by medium- and long-term operational research to determine their sustainability.

Prevention and Control of Neglected Diseases: A Multisectoral Problem

  1. Top of page
  2. Abstract
  3. Neglected Diseases Linked to Poverty, Governance, and Security
  4. Current Interventions for Control of Neglected Diseases
  5. Prevention and Control of Neglected Diseases: A Multisectoral Problem
  6. Intersectoral Action to Combat Neglected Diseases and Poverty
  7. Acknowledgments
  8. Conflicts of Interest
  9. References

The application of epidemiological and operational research to the prevention and control of the NDs over the decades has resulted in a scientific literature that is fairly rich in the identification of risk factors and protective factors for several, but not all, NDs. Recent improvements in the tools and applications of meta-analysis of risk factors have further strengthened the potential to extract clear lessons learned from such research, though these have yet to be widely applied to the NDs; some examples include meta-analysis of the relationships between epilepsy and onchocerciasis8 and risk factors for subtle schistosomiasis morbidity9 and relationships between water resource projects and schistosomiasis risk.10

Ehrenberg and Ault11 have summarized the multifactorial determinants of disease, including intrinsic determinants, such as genetic makeup, and immune response to extrinsic determinants, such as poverty, human activities in the environment, and vector ecology and behavior. The extrinsic and intrinsic determinants of communicable diseases, including the NDs, will often synergize negatively when clustered together. Poor populations, such as many rural indigenous communities, migratory farm workers, and slum-dwellers, often suffer from deficient diets, which lead to immune deficiencies and micronutrient deficits. These in turn reduce their resistance to infection or coinfection with parasites and ectoparasites. Poor families and communities are often also forced to live in degraded or high-risk natural environments, increasing risk of contact with disease vectors and pathogens, such as Buruli ulcer. Their status is also usually accompanied by poor housing, water supply, and sanitation, which further compound the risks of outbreaks or heavy burdens of NDs. Where poor environmental conditions combine with high population densities in poor communities and households (whether in rural villages or slums), it is common to observe clustering of NDs and coinfections in individuals.12,13

The situation may be further exacerbated in such poor households and communities by coinfections with other important communicable diseases, such as malaria (e.g., anemia from malaria–STH coinfection) and human immunodefieicncy virus (HIV). Strikingly, Stillwaggon14 reviews some evidence that individuals infected with schistosomiasis are more susceptible to HIV infection and that individuals who receive a combination of deworming (for STHs) and vitamin supplements may reduce HIV transmission in poor African communities. Helminth infections as a cofactor driving HIV epidemics are further discussed by Hotez et al.15

As Stillwaggon14 notes, the environment of poverty is complex, and the NDs form an integral part of this web. As described earlier, risk factors and protective factors for several NDs have been identified in sectors or areas other than health. Some specific examples include improved housing for controlling certain Chagas, disease vectors; improved water supply and cloth filters for dracunculiasis elimination; improved water supply and sanitation combined with health education for STH, filariasis, and trachoma prevention and control; vegetation and peridomicile management for leishmaniasis and Chagas, disease vector control; and limiting human contact with forest or riverine environments to prevent transmission of HAT, onchocerciasis, and leishmaniasis. Also, there are even more creative ways to combat NDs by addressing some of the root causes of the burden of NDs, as described next.

Intersectoral Action to Combat Neglected Diseases and Poverty

  1. Top of page
  2. Abstract
  3. Neglected Diseases Linked to Poverty, Governance, and Security
  4. Current Interventions for Control of Neglected Diseases
  5. Prevention and Control of Neglected Diseases: A Multisectoral Problem
  6. Intersectoral Action to Combat Neglected Diseases and Poverty
  7. Acknowledgments
  8. Conflicts of Interest
  9. References

What are some of the microlevel actions and examples of successfully combating both NDs and poverty in developing economies and poor communities by working with other sectors? Three principal avenues can be identified. The first avenue is through nutritional and food security interventions to reduce anemia and undernutrition. In poor communities it is common for children to suffer from anemia and undernutrition because of a combination of STH infections and family food deprivation. The important nature of complementary nutritional interventions (micronutrient provision, particularly vitamin A and iron, supplemental feeding) accompanied by deworming is recognized by nutritionists, community health specialists, nongovernmental development organizations (NDGOs), and United Nations agencies, such as UNICEF and the World Food Program, which implement community-wide interventions to combat child and maternal malnutrition. These agencies have practices and policies in certain settings that extend beyond deworming, micronutrient provision, and supplemental feeding to address some of the causes of rural malnutrition. They provide training in home and community gardening and improved subsistence farming and forestry practices, small-scale livestock production, and microcredit access to women to promote the establishment of family gardens and orchards and other rural subsistence businesses.

Some NDGOs, such as the World Wildlife Fund, and bilateral agencies, such as DFID, GTZ, and USAID, have actively promoted agroforestry as a positive contributing factor to community health through its direct effects of provision of tree fruits and nuts to malnourished families and indirect effects on improving income to purchase foods and medicines or travel to health clinics for care. Other NDGOs, such as Heifer International, seek the same objective through the provision of small animals (poultry, ducks, rabbits, and guinea pigs), small livestock (goats), fish, or honeybees to contribute to both family nutrition and income generation. As a whole, these interventions can increase family food security and improve nutritional status.

The second avenue is through education and school health. The FRESH initiative (Focusing Resources on Effective School Health) led by the World Bank with WHO and other partners is a model that integrates four key components: health-related school policies; provision of safe water and sanitation; skill-based health education; and school-based health and nutrition services, including deworming and micronutrient supplementation. Deworming alone can increase rural elementary school attendance by up to 25% in STH-endemic areas in Tanzania16; the other components of the FRESH program only further strengthen that intervention. Interventions, such as mass deworming of schoolchildren, which increase the opportunities for children, particularly girls, to complete primary and secondary schools, strengthen family economies and address the severe economic gender-based gap seen in many developing economies. Indeed, mass deworming of schoolchildren has been named a “best buy” for both education and health by the MIT Poverty Action Lab.17

The third avenue is through environmental interventions. The Pan American Health Organization (PAHO)/WHO and UNICEF work with Primary Environmental Care, an integrated and participatory approach to solving community environmental problems on the basis of community diagnosis, dialogue with experts, advocacy, and municipal and stakeholder participation. Water and sanitation–related NDs have been targeted for priority community actions in Guatemala and elsewhere using this strategy. The Biodiversity Support Program coordinated by the World Wildlife Fund18 has implemented several wildlife and habitat conservation projects, principally in indigenous communities that have environmental health components to address diarrhea, dysentery, and inadequate drinking water and sanitation. Other health interventions by the World Wildlife Fund/Biodiversity Support Program in Latin America and Africa included mobile health team visits, primary health care postconstruction, family planning services, sustainable medicinal plant and wild plant harvests to help residents remain healthier and better nourished, and more effective participation in local World Wildlife Fund conservation programs. USAID's Environmental Health Project implemented an Integrated Population Health and Environment Program in Madagascar that included a large series of environmental and health interventions that reduced the prevalence of several diseases in the target communities19; the interventions included reforestation, forage crops, beekeeping, off-season gardening, fish culture, fruit trees, plant nurseries, microcredit for income generation, antierosion measures, market gardens, potable water, sanitation and hygiene, vaccinations, diarrheal disease and malaria treatment, nutrition interventions (vitamin A), animal husbandry, and ecosystem protection.

One is not limited to these three interventions while seeking to build intersectoral approaches to combat NDs and address poverty. Ault20 noted that a practical package of intersectoral approaches may include the following:

  • • 
    Establishing intersectoral technical committees and networks of stakeholders
  • • 
    Improving water supply and sanitation in high-risk communities
  • • 
    Strengthening links between the communicable diseases and the agricultural and livestock sectors
  • • 
    Advocacy and communication with at-risk communities and key external stakeholders about the environmental and social determinants of health, security, and poverty
  • • 
    Community mobilization and participation
  • • 
    Partnerships
  • • 
    Environmental education
  • • 
    Community economic development

Ehrenberg and Ault11 note that intersectoral interventions are expected to be cost-effective, by piggybacking or articulating ND control interventions with other interventions that can reduce poverty, increase family health and economic security, and promote sustainability. Where costs of ND control are shared between the health sector and other sectors, or where actions by other sectors reduce the prevalence, morbidity, or distribution of NDs, it may be considered a cost-effective action from the perspective of the health sector's financial director.

PAHO's communicable diseases unit in collaboration with veterinary public health unit has developed an integrated and intersectoral project proposal for the Chaco region, a harsh and impoverished area inhabited principally by agrarian indigenous communities, in the border areas of Paraguay, Bolivia, and Argentina. In the Chaco, the NDs include the STHs, cutaneous leishmaniasis, Chagas, disease, and skin diseases. Malnutrition is widespread. The Chaco project is multidisciplinary and focuses on ND prevention and control through primary health care, poverty alleviation through improved livestock production and subsistence food production, and environmental management and protection. It reflects several initiatives outlined by Holveck et al.4 for Latin America and the Caribbean, including a focus on health of indigenous peoples, healthy spaces, productive municipalities, community-driven development, and intersectoral cooperation between agriculture and health; the project also addresses the issue of public health and human rights for these isolated disadvantaged communities. Stakeholder meetings are expected to begin in 2008, and the 5-year project will be evaluated for its intersectoral effects, cost-effectiveness, and sustainability.

The WHO's new Global Plan to Combat Neglected Tropical Diseases 2008–201521 recognizes the importance of intersectoral action to control and eliminate NDs. An intersectoral approach to combating NDs and poverty also supports all eight of the United Nations Millennium Development Goals,11 including those that target the eradication of hunger; promoting primary education (by increasing school attendance); empowerment of women; reducing child mortality; improving maternal health; combating HIV, malaria, and other diseases; and ensuring environmental sustainability in areas, such as urban slums. The PPPs created to tackle the NDs also contribute to the Millennium Development Goal of global partnerships for development.

Acknowledgments

  1. Top of page
  2. Abstract
  3. Neglected Diseases Linked to Poverty, Governance, and Security
  4. Current Interventions for Control of Neglected Diseases
  5. Prevention and Control of Neglected Diseases: A Multisectoral Problem
  6. Intersectoral Action to Combat Neglected Diseases and Poverty
  7. Acknowledgments
  8. Conflicts of Interest
  9. References

I thank Drs. J.P. Ehrenberg, M. Roses, P. Hotez, and J. Utzinger, as well as various managers, technical staff, consultants and interns from PAHO and WHO, whose ideas and our conversations have contributed to the development of this theme and this report.

Conflicts of Interest

  1. Top of page
  2. Abstract
  3. Neglected Diseases Linked to Poverty, Governance, and Security
  4. Current Interventions for Control of Neglected Diseases
  5. Prevention and Control of Neglected Diseases: A Multisectoral Problem
  6. Intersectoral Action to Combat Neglected Diseases and Poverty
  7. Acknowledgments
  8. Conflicts of Interest
  9. References

The author is a staff member of PAHO/WHO and declares no conflicts of interest; however, the contents of this report are the sole responsibility of the author and should not be construed as speaking for the policies of PAHO/WHO or their governing councils and assemblies. This report is a contribution to the current global dialogue on poverty alleviation and the Millennium Development Goals.

References

  1. Top of page
  2. Abstract
  3. Neglected Diseases Linked to Poverty, Governance, and Security
  4. Current Interventions for Control of Neglected Diseases
  5. Prevention and Control of Neglected Diseases: A Multisectoral Problem
  6. Intersectoral Action to Combat Neglected Diseases and Poverty
  7. Acknowledgments
  8. Conflicts of Interest
  9. References
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