A1REGIONAL APPROACHES TO NEGLECTED TROPICAL DISEASES CONTROL IN LATIN AMERICA AND THE CARIBBEAN

Ault SK, Periago MR.

Neglected [tropical] diseases impose a huge burden on developing countries, constituting a serious obstacle for socioeconomic development and quality of life … Thus, taking decisive action to eliminate them as a public health problem in the Region, which is an achievable dream—provided the necessary political commitment and resources are in place—for which we are working in PAHO, would also be a clear reassertion of our countries' deep commitment with human rights as enshrined in international treaties and standards.

—Mirta Roses Periago, Director, Pan American Health Organization (Director's Blog, April 8, 2008, http://66.101.212.220/mirtaroses/index.php?id=69)

Background

In the Latin America and Caribbean region (LAC) at least 180 million people live below the poverty line. These impoverished and marginalized populations are often heavily burdened with neglected tropical diseases (NTDs) and other infectious diseases of poverty. This group of diseases continues to take a measurable toll, not only on families and communities but also on the socioeconomic development of nations.

NTDs and Their Impact

The NTDs largely comprise infectious and parasitic tropical diseases. Today, NTDs can be usefully considered as a group because they are concentrated almost exclusively among impoverished populations living in marginalized areas whether rural or peri-urban. These incapacitating diseases, such as lymphatic filariasis, onchocerciasis or river blindness, schistosomiasis (including bilharzia), soil-transmitted helminthiasis (ascariasis, trichuriasis, and hookworm infection), Chagas disease, leishmaniasis, leprosy or Hansen's disease, and trachoma continue to perpetuate poverty, generate prejudice, or inflict severe incapacity (lymphatic filariasis), disability (e.g., leprosy/Hansen's, onchocerciasis), and sometimes premature death (e.g., Chagas disease and schistosomiasis) in LAC and other regions of the world. Children with heavy intestinal worm burdens may become stunted or anemic, or they may suffer from maldigestion, malabsorption, and poor physical and cognitive development. These worms can reduce school attendance, attention span in class, and test scores. Infection with NTDs reduces income-earning capacity, and this in turn often creates a loss of the ability to care for a family.

Social Determinants

Although biologically and medically diverse, NTDs share features that allow them to persist in conditions of poverty where they frequently overlap (Brooker et al., 2006). These conditions of poverty include unsafe water, poor sanitation, and refuse disposal, which sustain transmission cycles and favor the proliferation of vectors that transmit disease. Other conditions, such as a lack of access to health services, low levels of literacy, inadequate nutrition and poor personal hygiene all help to increase vulnerability to infection and work against prevention efforts. Addressing these social determinants of poverty complements the use of existing tools to combat and eliminate NTDs. Specific technical opportunities to control and eliminate NTDs in LAC through intersectoral and multidisease approaches while addressing social determinants were recently reviewed (Ault, 2008; Ehrenberg and Ault, 2005; Holveck et al., 2007; Hotez et al., 2008), and provide background for this paper.

Legacy of Slavery

Interestingly, some of the NTDs—for example lymphatic filariasis (LF), onchocerciasis, and schistosomiasis—are parasitic diseases that were imported to the Western Hemisphere through the European slave trade, which targeted Africa. Today, a little more than 200 years after the end of that colonial slave trade, they still cause substantial morbidity and are particularly attractive targets of elimination. As noted by Lammie et al. (2007), “the elimination of diseases that are a consequence of this trade will represent a tangible contribution to the health and well being of people and communities who, arguably, still suffer from the residual affects of slavery.”

Tools and Mandate to Combat

Tools exist today to effectively combat the NTDs, including safe and inexpensive antihelminthics, dose poles, quantitative and rapid mapping methods, and rapid test kits for several parasites, and having these tools in hand makes it an ethical imperative to work toward the control and elimination of NTDs. Since 2007, the Pan-American Health Organization (PAHO) also made headway in the scientific and political debate that guided the development of an elimination agenda and made it possible to subsequently mobilize the necessary will and resources. In 2009, PAHO received a mandate in the form of a resolution (CD49-R19) from its Directing Council (composed of the Ministers of Health of the region) to support the countries in the region in eliminating or significantly reducing the burden of a group of 12 neglected diseases and other poverty-related infections. This chapter discusses this mandate and the region's plans to tackle and eliminate several NTDs over the next five years.

Elimination Agenda

Working together, the LAC countries and PAHO have had significant success in eliminating several infectious diseases in the region in the recent decades: smallpox (1977), poliomyelitis (1994, wild poliovirus), and measles (2002). As well, at the end of 2010, onchocerciasis transmission has been apparently eliminated in 8 of 13 foci among six endemic countries in the region. The number of human cases of rabies transmitted by dogs in Latin America dropped significantly, by nearly 90 percent, between 1990 and 2007 (PAHO, 2009).

A significant reduction in the transmission of Chagas disease by two important domestic vectors (Rhodnius prolixus and Triatoma infestans) in the 21 endemic countries has been achieved since 1990 principally as a result of systematic indoor spraying with residual pyrethroid insecticides of houses in rural endemic areas, infection and mortality have declined as has the population at risk (Table A1-1). As of 2010, 10 countries have eliminated these vectors and 3 others have eliminated them in parts of their national territories. A reduction in blood transfusion–origin Chagas disease has also been achieved in the region, as endemic countries began universal screening of blood donors at blood banks using a rapid Enzyme-linked immunosorbent assay (ELISA) test.

TABLE A1-1. Evolution of Change in Epidemiological Parameters of Chagas Disease in LAC.

TABLE A1-1

Evolution of Change in Epidemiological Parameters of Chagas Disease in LAC.

What Is Feasible?

There is broad technical consensus that there are available tools and strategies to combat several neglected tropical diseases that have been included in the World Health Organization's (WHO's) 2008–2015 Global Plan to Combat Neglected Tropical Diseases (WHO, 2007). Beginning in 2007, PAHO began to review the data to determine which of these NTDs and other infectious diseases of poverty we can eliminate or significantly reduce transmission of in the entire region by 2015, such as onchocerciasis, LF, and trachoma. PAHO reviewed others that can be eliminated in certain subregions or in a particular country, as in the cases of plague in Peru and Ecuador, schistosomiasis in St. Lucia and Suriname, and malaria in the Caribbean and Central America. The agency focused on identifying successful strategies for control and elimination, collecting epidemiological data on the presence and prevalence of these diseases in the region, and preparing maps down to the first administrative level of where the diseases overlapped geographically. With these data and information in hand, PAHO published its epidemiological profiles of 10 neglected diseases in 14 countries in early 2009 (PAHO, 2009).

Next, a regional elimination strategy was developed during 2009 by the agency's communicable diseases project for 10 neglected diseases of poverty with input from PAHO technical staff, managers and external experts, and the draft strategy was vetted with the Ministers of Health and approved by the Directing Council in October 2009 as Resolution CD49-R19. In approving the resolution, the Member States of the region have committed to an objective by 2015 to eliminate or reduce neglected diseases and other infections related to poverty for which tools exist, to levels such that these diseases are no longer considered public health problems. This effort requires long-term political and financial commitment and the preparation and implementation of integrated national plans of action (POAs). In 2010, several countries in the region have now established national committees with the objective to develop their POAs for the integrated control and elimination of NTDs.

The PAHO strategy uses two definitions for elimination, depending on the disease. The elimination of a disease is a reduction to zero of the incidence of a given disease in a defined geographic area as a result of deliberate efforts, with continued intervention measures being required (WHO, 1998). Elimination of a disease as a public health problem occurs by drastically reducing the disease's burden to a level that is acceptable given the current tools available and the region's health situation. At this level, the prevalence of the disease does not constrain social productivity and community development. Achievable goals have been established for each disease. In this chapter, both definitions are used to select the diseases targeted for elimination, according to previous global and regional mandates for elimination.

PAHO considered the following criteria in selecting the diseases that could feasibly be eliminated or drastically reduced in the region: (a) the “unfinished agenda”—diseases that already had been priority targets for elimination by PAHO or WHO and for which, despite progress made, some areas lagged behind; (b) technical feasibility—including the availability of knowledge and tools for structuring interventions to interrupt or reduce transmission; (c) regional evidence of achievable elimination—existence of successful regional experiences in accomplishing elimination at country or subnational levels; (d) economic criteria—including relatively low unit cost of interventions and demonstrated cost-effectiveness; (e) unequal burden of disease—wherein the more vulnerable populations (such as indigenous and Afro-descendant populations, women, and children who have been historically excluded) suffer from a higher prevalence and social consequences of these diseases, thus perpetuating the cycle of poverty; (f) political relevance—the diseases must be recognized as being of public health importance with a broad international appeal, which could be expressed through existing resolutions approved by the World Health Assembly or PAHO's Directing Council; and (g) best practices, including those utilized in primary health care, well-accepted interventions such as mass preventive chemotherapy and high-coverage vaccination campaigns, integrated approaches for vector-borne diseases, and local projects with community participation to improve health through intersectoral action. These examples of best practices have already been developed in the region and will provide the basis for the scale-up of local and national proposals for disease elimination.

The selected diseases were classified into two groups, those with greater potential for being eliminated, and those that can be drastically reduced with available tools. Group 1 diseases are those that have a greater potential for being eliminated: Chagas disease (vector-borne and transfusional transmission, both as a public health problem); congenital syphilis (as a public health problem); LF (as a public health problem); onchocerciasis; rabies transmitted by dogs; neonatal tetanus (as a public health problem); trachoma (as a public health problem); leprosy (as a public health problem at the national and first subnational level); malaria (elimination in Haiti and the Dominican Republic and in México and Central America); and plague (as a public health problem). Cost-effective strategies and tools exist for elimination, there is evidence of feasibility of elimination in other countries or areas in LAC, or there are global or regional mandates to reach elimination. Next, we highlight two of the Group 1 diseases, onchocerciasis and lymphatic filariasis.

Onchocerciasis is endemic in parts of Africa and in 13 foci in six countries of the Americas where it was introduced through the slave trade. It is estimated that more than half a million people live in areas of México, Guatemala, Colombia, Ecuador, Venezuela, and Brazil where documented transmission of onchocerciasis occurs or has been documented in the recent past. The basic strategy for achieving elimination in this Region is mass drug administration (MDA) using a form of ivermectin (Mectizan®, a donated medicine) given twice a year to at least 85 percent of all eligible population, accompanied by health education and promotion of community participation for at least 10 consecutive years. The minimum required coverage in all the 13 foci in the Region was achieved in 2002 and has been maintained since. New cases of onchocercal blindness were eliminated since 2007. However, some cases of ocular morbidity still occur in a few foci, mainly in the Amazon region of Southern Venezuela and Northern Brazil inhabited by the Yanomami Amerindians. As of January 2011 onchocerciasis transmission has been interrupted in 8 of the 13 foci, with those currently being in the post-treatment surveillance phase. Transmission is suspected to be suppressed in two other foci: South Chiapas in México and the Central focus in Guatemala. Onchocerciasis transmission persists in the three foci (Northeastern focus of Venezuela, and the southern focus of Venezuela and northern focus of Brazil, which share the Yanomami area (epidemiologically, it constitutes one shared focus). The Yanomami area represents the greatest challenge to the regional elimination efforts.

Lymphatic filariasis, another NTD imported to LAC by the trans-Atlantic slave trade, was common in port cities, some Caribbean islands, and coastal areas in the Region until the last century when advances in sanitation began to reduce and then interrupt transmission by its Culex mosquito vector. In the past few decades three countries (Costa Rica, Suriname, and Trinidad and Tobago) have presented evidence of interruption of transmission, together with two cities in Brazil (Belém, Pará state and Maceió, Alagoas state). Today more than 9 million people are considered at risk for lymphatic filariasis in four endemic countries in the Region (one focus in metro Recife, Brazil, and Guyana, Dominican Republic and Haiti), with the highest proportion living in Haiti. People at risk benefit from more than 10 years of effort to eliminate transmission by MDA with the drugs diethlycarbamazine and albendazole. In 2009 about 3.4 million were treated via MDA. The January 2010 earthquake in Haiti and the Dominican Republic complicated the timely delivery of medicines. A meeting convened by PAHO in February 2010 with international partners created solidarity in support of Haiti to continue the work and reach the elimination goal, which helped enable the Haitian Ministry of Health and Population's MDA program to pick up and continue in 2010. Ministries of Health are intensifying their efforts to eliminate the remaining foci in Brazil, Dominican Republic, and Guyana.

Group 2 diseases are those whose burden can be drastically reduced with available tools: schistosomiasis and soil-transmitted helminthiasis (STH), for which there exist safe and very effective drugs and a record of success in greatly reducing intensity of infection though MDA in a strategy of preventive chemotherapy. In LAC, the parasites targeted are Schistosoma mansoni (the only human schistosome in the region) and the three common types of STHs (Ascaris lumbricoides, Trichuris trichura, and the human hookworms Ancylostoma duodenale and Necator americanus). They persist in some areas (poor rural communities or peri-urban shantytowns), sometimes with a very high prevalence (more than 50 percent) in vulnerable populations like children; however in many countries there is very limited or no recent epidemiological data about their distribution, prevalence, and burden, hampering awareness and adequate interventions.

Soil-transmitted helminthiasis is considered to be present in all the LAC Region's countries, with prevalence varying. PAHO estimates conservatively that 13 million preschool-age children and 33 million school-age children are at risk of STH infections in the Region, where transmission is closely associated with a lack of access to basic sanitation and safe water. A handful of countries have established national deworming programs, principally for school-age children, while in other countries various international nongovernmental organizations (NGOs) contribute to deworming efforts through their community-targeted interventions. Epidemiological information on STH is sparse, as these infections are not reportable; however, in PAHO's review of published prevalence rates some surveys have indicted prevalence higher than 50 percent in some groups of school-age children and indigenous populations, and intensity of infection varies but has been seen high enough to be associated with adverse health effects like anemia. The Region's high-risk countries are being encouraged and supported to scale-up deworming efforts to reach all vulnerable populations.

In LAC, PAHO estimates that approximately 1.8 million persons are infected, and up to 25 million are at risk of schistosomiasis. Schistosomiasis infection occurs in humans in contact with infested freshwater reservoirs when the cercarial stage of the parasitic fluke leaves the intermediate host snail and penetrates the person's skin and enters the bloodstream. The drug praziquantel is the recommended treatment, which can be provided by MDA or individual treatment. MDA with praziquantel can interrupt transmission. Today the disease is limited to four countries in LAC: parts of Brazil (principally the northeast of the country), St. Lucia, and parts of Suriname and Venezuela. Morbidity appears low, and reported deaths (from Brazil) are few. Brazil's national schistosomiasis control program has, over the decades, significantly reduced morbidity and mortality, while the other countries treat cases as encountered; Suriname and St. Lucia are taking steps to eliminate the disease while Venezuela is evaluating its epidemiological situation.

For other infectious diseases, such as leishmaniasis and leptospirosis, the burden of the disease needs to be further assessed, better tools need to be developed for diagnosis (e.g., leishmaniasis), and methods and strategies for achieving cost-effective and sustainable prevention and control need to be established (e.g., leptospirosis, cysticercosis/taeniasis). For these diseases and for others that have epidemiological relevance to some of the region's countries, more operational research needs to be conducted, new tools need to be assessed, and surveillance systems need to be improved.

Framework for Elimination

The public health strategies and interventions that are used to eliminate or reduce infectious diseases to acceptable levels go beyond routine control measures. In order to strengthen the efforts against diseases related to poverty as a group, endemic countries can develop integrated POAs under the same framework, while considering the following:

  • Available plans at the global, regional, or country level to eliminate or control these diseases.
  • Available guidelines for the selected diseases to support the countries in achieving the goals of elimination or control.
  • Available tools such as drugs and diagnostic techniques to support surveillance systems.
  • Evidence-based decisions for strengthening health surveillance systems, mapping the diseases to identify remaining foci, and identifying overlapping of diseases in geopolitical areas (“hot spots” or areas of co-endemicity) for integrated action.
  • Reducing gaps in tool-ready neglected diseases in deficit areas in the region.
  • Ensuring that the necessary resources are available for the primary care system to integrate NTD control and help reduce inequalities in health.
  • Pursuing inter-programmatic interventions that integrate the various existing plans into a comprehensive vision based on the epidemiology and social determinants of each area identified for intervention (hot spots); interventions should tackle the factors and mechanisms through which social conditions affect the community's health and, where possible, address them through social and health policies.
  • Pursuing community participation and intersectoral partnerships: the community, stakeholders and all actors and potential partners within and outside the health sector should be enlisted to make actions sustainable.
  • Pursuing horizontal cooperation: identify which countries share problems or borders where the selected diseases occur, to promote joint actions and intercountry plans.
  • The increase in donor support from global partners in the fight against neglected tropical diseases and other infections related to poverty.

Progress, Priorities, and Lines of Action for Elimination

PAHO partnered with the Inter American Development Bank (IDB) and the Global Network for Neglected Tropical Diseases (GNNTD, or Global Network [GN]) based in the Sabin Vaccine Institute beginning in 2008. With the IDB and the GN the partners have established a Trust Fund for Neglected Infectious Diseases in the IDB and are working to capitalize the fund in 2011. Additionally the partners have worked together and with Ministries of Health to develop a POA and demonstration project in the State of Chiapas México projects, and another demonstration project in the metropolitan area of Recife, northeast Brazil, which are meant to demonstrate or show proof of principle of integrated approaches to NTD control and elimination in the LAC Region. The Chiapas demonstration project covers trachoma, Chagas disease, leishmaniasis, rabies transmitted by dogs, onchocerciasis, and STHs. The project in metropolitan Recife tackles schistosomiasis, STHs, LF, and leprosy/Hansen's disease. Each project will become operational in 2011. Meanwhile, several countries, including Guyana, Suriname, Dominican Republic, and Haiti, are developing integrated POAs to combat multiple NTDs, and more countries will begin the process in 2011.

In collaboration with the GNNTD, in 2010 PAHO began a process to map NTDs down to lower administrative levels (municipal levels) in several countries. With the Swiss Tropical Institute and Louisiana State University, PAHO is using environmental and social parameters and Bayesian modeling to map the expected distribution and prevalence of Chagas disease, schistosomiasis and STH in Brazil, Bolivia, and Colombia. This modeling approach is expected to be extended to additional countries in 2011. Additionally, PAHO has worked with the Autonomous University of Yucatán, México, to study the social determinants of STHs, Chagas disease, and dengue in peri-urban and rural communities near the city of Mérida.

To operationalize the strategies and interventions needed to eliminate NTDs in the region, PAHO also prepared a report in 2010 analyzing progress in control and elimination of five NTDs amenable to preventive chemotherapy, prioritizing the associated endemic countries with respect to these five diseases and identifying lines of action to take to achieve elimination by 2015 (PAHO, 2010).

This report, referred to as the Prioritization Report, is a qualitative analysis of gaps and needs in technical cooperation and is presented in order to make progress toward the elimination goals for these five diseases in 33 countries in LAC: onchocerciasis, schistosomiasis, trachoma, LF, and soil-transmitted helminthiasis.

As a result of the analysis, countries were classified and prioritized into four groups.

Group 1 This group concentrates the majority of population at risk for the main NTDs. These countries have 66.8 and 67.4 percent of preschool-age children (Pre-SAC) and school-age children (SAC) populations, respectively, at risk in LAC for STHs. Four countries have foci of onchocerciasis with 421,000 people at risk. Three countries have foci of schistosomiasis with up to 25 million people at risk. Three countries have foci of trachoma with up to 50 million people living in risk areas, and four countries have foci of LF with more than 9 million people at risk. This group includes countries working to eliminate onchocerciasis, LF, and trachoma, and one country with the possibility to eliminate schistosomiasis; Suriname is expecting external verification of LF elimination. This group needs technical cooperation to develop and implement integrated, interprogrammatic, and intersectoral plans to combat neglected infectious diseases (NIDs) including STHs (Table A1-2).

TABLE A1-2. Diseases, Foci, Population at Risk, and Treatment Coverage in Group 1 Countries.

TABLE A1-2

Diseases, Foci, Population at Risk, and Treatment Coverage in Group 1 Countries.

Group 2 This group has 26.8 and 26.1 percent of Pre-SAC and SAC populations, respectively, at risk for STHs in LAC. Two countries have foci of onchocerciasis with 115,070 people at risk. One country has foci of schistosomiasis. There is no evidence of LF transmission in this group of countries. However, recently Miller et al. (2010) provided clinical evidence of trachoma in an Amerindian indigenous community in the Department of Vaupés, Colombia documenting the presence of trachoma for the first time in Colombia.

This group includes countries also eliminating onchocerciasis and targeting schistosomiasis. These countries need technical cooperation to improve current interprogrammatic and intersectoral coordination and to include STHs into NID-integrated actions (Table A1-3).

TABLE A1-3. Diseases, Foci, Population at Risk, and Treatment Coverage in Group 2 Countries.

TABLE A1-3

Diseases, Foci, Population at Risk, and Treatment Coverage in Group 2 Countries.

As mentioned above, most of the LAC countries have no updated results of nationwide surveys of prevalence and intensity of infection of STH and schistosomiasis and trachoma. Groups 1 and 2 have the greatest gaps in sanitation coverage and a clear opportunity to integrate intersectoral and interprogrammatic actions for integrated NTD control, in the framework of primary health care systems and addressing the social determinants of health.

Group 3 This group has 5.4 percent of Pre-SAC and SAC population at risk for STHs in LAC. There is no evidence of the presence of onchocerciasis, schistosomiasis, trachoma, or LF. These countries need technical cooperation to focus activities for NIDs at local level and rural areas, with emphasis on STHs.

Group 4 This group has 1.03 and 1.1 percent of Pre-SAC and SAC populations, respectively, at risk for STHs in LAC. There is no evidence of the presence of onchocerciasis, schistosomiasis, trachoma, or LF. Costa Rica and Trinidad and Tobago are expecting external verification of LF elimination.

The classification is used to define the nature of external technical cooperation that each group may require to mobilize resources needed for elimination. It is important to note that if actions were focused on all populations of Groups 1 and 2, the following groups could be reached (see Table A1-4 for details):

TABLE A1-4. Pre-SAC and SAC Population at Risk for Soil-Transmitted Helminths (STHs) in LAC, 2009.

TABLE A1-4

Pre-SAC and SAC Population at Risk for Soil-Transmitted Helminths (STHs) in LAC, 2009.

  • 84.5 million of people at risk for four diseases (i.e., onchocerciasis, schistosomiasis, LF, and trachoma); and
  • 94 percent (12,088,816) of Pre-SAC and 93.5 percent (29,927,933) of SAC populations at risk for STHs in LAC, who could be reached with deworming activities.

Opportunities for Integration

In the PAHO map below (Figure A1-1), six NTDs are shown in 14 countries for 2008: schistosomiasis, STHs, onchocerciasis, LF, trachoma, and human rabies transmitted by dogs. The diseases are mapped at the first “administrative” level of the country. Among these countries, 275 administrative units (e.g., states, provinces, departments etc.) reflect the co-endemicity of diseases. Three of the units (the states of Maranhão, Pernambuco, and Sergipe in Brazil) have the presence of four of the six NTDs selected for the PAHO study. Twelve other units present with the presence of three of the six diseases, while 41 units had two NTDs present. This 2008 analysis by PAHO revealed that, of the 580 million inhabitants of LAC, some 241 million live in units with the presence of at least one of these diseases.

A map showing overlapping of six neglected infectious diseases in 14 countries

FIGURE A1-1

Overlapping of six neglected infectious diseases. SOURCE: PAHO (2009)

The mapping efforts of PAHO have shown the potential for integrated control and elimination where two or more NTDs overlap in space and time. Efficiencies and economies of scale can be achieved, and local health workers can be trained to manage multiple diseases in the areas of endemicity.

PAHO has identified several principles for integrating actions for NTD control and elimination. They include the following:

  • Available plans, guidelines, and tools to develop integrated POAs (instead of reinventing the wheels of successful stand-alone programs);
  • Evidence-based decisions (using the data about disease overlap and burden);
  • Reduction of inequalities in health (to justify resources for integrated control);
  • Primary health care systems (as a principal service delivery platform for NTD control);
  • Community participation (in surveillance, control, education, monitoring and evaluation);
  • Gender and ethnicity (as a way to target those most likely deprived);
  • Interprogrammatic and intersectoral interventions to address the social determinants of health (water and sanitation, drainage, housing, and nutrition);
  • Cooperation between countries (where one endemic country is well positioned to help another endemic country); and
  • Global partnerships in the fight against NIDs (allowing significant drug donations and provision of training and other resources).

The agency sees multiple approaches to integrate actions for NTD control and elimination, through inter-programmatic actions within a Ministry of Health. Common interventions may include the following:

  • Screening, drug treatment/MDA
  • Morbidity (case) management (LF, leprosy/Hansen's disease)
  • Integrated vector management
  • Water Supply, Sanitation, Hygiene, Health Education and Deworming (WASHED) strategy
  • Education and school health for deworming
  • Vitamin A + deworming medicine distribution
  • Other micronutrients (Fe, I, Zn, multi-vitamin) distribution + deworming
  • Food vouchers and complementary nutrition to combat undernutrition, combined with deworming
  • Food security programs to reduce undernutrition and anemia
  • Conditional cash transfers to encourage mothers to bring children to regular medical visits and receive NTD screening and deworming
  • Integrated population, health, and environment programs
    *

    Agroforesty, home gardens, aquaculture, and beekeeping to reduce undernutrition and anemia

    *

    Primary environmental care to create protective environments against NTDs

To deliver such interventions, Ministries of health may use other ministry health programs as common delivery platforms for NTD services, for example, for the distribution and delivery of antihelminthics or rapid screening tests, or patient care (case management for leprosy/Hansen's and LF cases) can be delivered. Some of these platforms include

  • Primary health care
  • Vector control
  • Nutrition/micronutrients
  • Immunizations (children, adolescents, pregnant women)
  • Maternal-child health, family health and wellness
  • Skin disease clinics, diabetes/chronic diseases clinics
  • Food security, food safety
  • Healthy schools, healthy cities
  • Malaria and TB programs

Piecing the Puzzle Together

The elimination and control of NTDs can be considered to consist of three categories: information and planning, delivery of services, and the development of integrated POAs. These are depicted in Figure A1-2. The information and mapping category includes an important aspect—stakeholder identification and mapping—allowing ministries to see what NGOs, faith-based groups, academia, and the private sector can bring to the table to support elimination. Additionally, the mapping of disease presence, prevalence, and burden, especially areas of overlap or co-endemicity, allows the visualization of the patches or hot spots where control efforts must be focused. Finally, the mapping of the social determinants of health (water supply and sanitation coverage, housing, agriculture and industry, and zones of malnutrition or unemployment) allows one to find and target populations most likely to be at risk of NTD infection. Delivery of health services for NTD control and elimination in poor communities is often best done through the primary care system, supplemented by other interventions as needed. Sets of minimum packages of treatment or care can be established for each group of co-endemic diseases, and these can be complemented by the necessary (and disease-specific) social and environmental services needed to educate and prevent or mitigate disease transmission and morbidity.

A digram showing the elimination and control of NIDs in LAC

FIGURE A1-2

Elimination and control of NIDs in LAC: Putting the pieces together. SOURCE: PAHO (2010).

Conclusions

Through the use of existing tools, stepped-up advocacy, political commitment, development of partnerships, resource mobilization, and careful allocation of resources, and reflected in integrated plans of action, a number of NTDs can be eliminated in the LAC region, These include onchocerciasis and LF (and LF and malaria in Hispaniola) in children and adults, trachoma in school-age children, schistosomiasis in the populations of St. Lucia and Suriname, as well as domestic vectoral transmission and transfusional Chagas disease, among other NTDs. This is the most opportune moment in history to eliminate these diseases, and it is an ethical and moral imperative for the region's citizens and governments.

Acknowledgments

The authors are indebted to many PAHO/WHO technical staff and senior managers that have, over the past decade contributed with intelligence, foresight, advocacy, persistence, and hard labor, especially John Ehrenberg, Ximena Aguilera, Jarbas Barbosa, Marcos Espinal, Rodolfo Rodríguez, Santiago Nicholls, Martha Saboya, Christina Schneider, Roberto Salvatella, Zaida Yadon, Carlos Lara, and interns and medical residents of Spain. Additionally, colleagues from partner institutions have worked closely with PAHO to control and eliminate NTDs in the Region, including the WHO NTD Control Department and WHO/TDR, the U.S. Centers for Disease Control and Prevention, the Carter Center, the Onchocerciasis Elimination Program of the Americas, Sabin Vaccine Institute, Pan American Health and Education Foundation, and indirectly, the Bill & Melinda Gates Foundation.

The efforts of PAHO and the endemic countries to combat NTDs have also been aided by various international cooperation agencies, NGOs, universities, and research institutes. Among the key international cooperation partners are AECID (Spain), JICA (Japan), and CIDA (Canada), and the Inter-American Development Bank. Important collaborating NGOs include the Global Network for Neglected Tropical Diseases, Children Without Worms, Save the Children, and Vitamin Angels. Partners among the universities and research institutes include the University of the West Indies, University of Antioquia (Colombia), St. George's University (Grenada), Instituto Pedro Kouri (Cuba), FIOCRUZ (Brazil), Liverpool School of Tropical Medicine (UK), and McGill University (Canada), and in the USA: George Washington University, Johns Hopkins University, Emory University, University of Notre Dame, and Case Western Reserve University.

References

  1. Ault SK. Intersectoral approaches to neglected diseases. Annals of the New York Academy of Sciences. 2008;1136:64–69. [PubMed: 18579876]
  2. Brooker S, Alexander N, Geiger S, Moyeed RA, Stander J, Fleming F, Hotez PJ, Correa-Oliveira A, Bethony J. Contrasting patterns in the small-scale heterogeneity of human helminth infections in urban and rural environments in Brazil. International Journal of Parasitology. 2006 Sep;36:1143–1151. [PMC free article: PMC1783908] [PubMed: 16814294]
  3. Ehrenberg JP, Ault SK. Debate: Neglected diseases of neglected populations: Thinking to reshape the determinants of health in Latin America and the Caribbean, BMC Public Health. 2005. p. 119. http://www​.biomedcentral​.com/content/pdf/1471-2458-5-119.pdf. [PMC free article: PMC1318484] [PubMed: 16283932]
  4. Holveck JC, Ehrenberg JP, Ault SK, Rojas R, Vasquez J, Cerqueira MT, Ippolito-Shepherd J, Genovese MA, Roses Periago M. Prevention, control, and elimination of neglected diseases in the Americas: Pathways to integrated, inter-programmatic, inter-sectoral action for health and development. BMC Public Health. 2007 Jan 17;7:6. [PMC free article: PMC1797008] [PubMed: 17229324]
  5. Hotez PJ, Bottazzi ME, Franco-Paredes C, Ault SK, Roses Periago M. The neglected tropical diseases of Latin America and the Caribbean: A review of disease burden and distribution and a roadmap for control and elimination. PLoS Neglected Tropical Diseases. 2008;2(9):e300. [PMC free article: PMC2553488] [PubMed: 18820747]
  6. Lammie PJ, Lindo JF, Secor WE, Vasquez J, Ault Sk, Eberhard ML. Eliminating lymphatic filariasis, onchocerciasis, and schistosomiasis from the Americas: Breaking a historical legacy of slavery, PLoS Neglected Tropical Diseases. 2007. [February 7, 2011]. p. e71. http://www​.ncbi.nlm.nih​.gov/pmc/articles​/PMC2100373/pdf/pntd.0000071.pdf. [PMC free article: PMC2100373] [PubMed: 18060085]
  7. Miller H, Gallego G, Rodriguez G. Clinical evidence of trachoma in Colombian Amerindians of the Vaupés Province. Biomédica. 2010;30(3):432–439. [PubMed: 21713345]
  8. PAHO (Pan-American Health Organization) Epidemiological profiles of neglected diseases and other infections related to poverty in Latin America and the Caribbean. Washington, DC: PAHO; 2009. http://new​.paho.org/hq​/dmdocuments/2009/nds-epi-profiles.pdf.
  9. PAHO (Pan-American Health Organization) Control and Elimination of Five Neglected Diseases in Latin America and the Caribbean, 2010–2015. Washington, DC: PAHO; 2010. in press.
  10. WHO (World Health Organization) Global disease elimination and eradication as public health strategies. Bulletin of the World Health Organization; Proceedings of a conference held in Atlanta, GA, 23–25 February 1998; 1998. pp. 22–25. [PMC free article: PMC2305684] [PubMed: 10063669]
  11. WHO (World Health Organization) Global plan to combat neglected tropical diseases 2008–2015. Geneva: WHO; 2007. (WHO/CDS/NTD/2007.3)