Control of Chagas Disease

https://doi.org/10.1016/S0065-308X(05)61004-4Get rights and content

Abstract

The Southern Cone Initiative (Iniciativa de Salud del Cono Sur, INCOSUR) to control domestic transmission of Trypanosoma cruzi is a substantial achievement based on the enthusiasm of the scientific community, effective strategies, leadership, and cost-effectiveness. INCOSUR triggered the launch of other regional initiatives in Central America and in the Andean and Amazon regions, which have all made progress. The Central American Initiative targeted the elimination of an imported triatomine bug (Rhodnius prolixus) and the control of a widespread native species (Triatoma dimidiata), and faced constraints such as a small scientific community, the difficulty in controlling a native species, and a vector control programme that had fragmented under a decentralized health system. International organizations such as the Japan International Cooperation Agency (JICA) have played an important role in bridging the gaps between fragmented organizational resources. Guatemala achieved virtual elimination of R. prolixus and `reduction of Tri. Dimidiata and El Salvador and Honduras revitalized their national programmes. The programme also revealed new challenges. Tri. dimidiata control needs to cover a large geographic area efficiently with stratification, quality control, community mobilization, and information management. Stakeholders such as the National Chagas Program, the local health system and their communities, as well as local government must share responsibilities to continue comprehensive vector control.

Introduction

Control of Chagas disease caused by the parasite Trypanosoma cruzi in Latin America over the last two decades has been a substantial public health achievement. The incidence of Chagas disease was reduced by over 65% between 1990 and 2000, from an estimated 700 000 cases per year to fewer than 200 000 (Schmunis et al., 1996; WHO, 2002). The Southern Cone Initiative (Iniciativa de Salud del Cono Sur, INCOSUR) was launched in 1991, aimed at elimination of the main vector, the reduviid bug Triatoma infestans, and elimination of transfusional transmission of T. cruzi in Argentina, Bolivia, Brazil, Chile, Paraguay, and Uruguay (PAHO, 1993). Since transmission by triatomine bugs accounts for over 80% of Chagas disease transmission, and the initiative successfully eliminated domestic Tri. infestans over large areas, this large-scale regional cooperation has significantly reduced disease transmission (Table 1) (WHO, 2002). The interruption of domiciliary transmission of T. cruzi by Tri. infestans has already been certified in Uruguay, Chile, four provinces in Argentina, 10 states in Brazil, and one state in Paraguay (PAHO, 1998, PAHO, 1999a, PAHO, 2000a, PAHO, (2002a), PAHO, 2003a). This success suggested that Chagas disease control is no longer a technical issue, but a political, economic, and organizational problem (Dias and Schofield, 1999; Schofield and Dias, 1999; Dias et al., 2002).

Based on the success of INCOSUR, the concept of region-wide control of Chagas disease has expanded to other regions such as Central America, where the endemic countries are facing new challenges in vector control. The World Health Organization (WHO) adopted the common goal of the elimination of Chagas disease in Latin America by the year 2010. In 1997, Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama launched the Central American Initiative (Iniciativa de los países de Centroamérica, IPCA) and Colombia, Ecuador, Peru, and Venezuela launched the Andean Initiative (1997) to control vectorial and transfusional transmission of the disease. Mexico has begun a dialogue with IPCA, seeking to join in the control activities. In addition, the Amazon region has discussed launching a regional initiative for surveillance and control of sylvatic vector species. IPCA has made the most significant progress to date, especially in vector control. IPCA, however, must deal with an entomological, social, and political situation, which is different from that of the Southern Cone countries. The aims of this paper are to review the lessons of the Southern Cone Initiative and their application in Central America, and to discuss strategies to tackle the new challenges of sustainable triatomine control.

Section snippets

The Southern Cone Initiative

INCOSUR (the Southern Cone Initiative) provided valuable lessons for implementing Chagas disease control in the Americas. Recent reviews have evaluated the achievements of INCOSUR (e.g. Dias and Schofield, 1999; Morel, 1999; Schofield and Dias, 1999; Silveira and Vinhaes, 1999; Dias et al., 2002; WHO, 2002; Moncayo, 2003). These reviews summarize the following points:

  • (i)

    INCOSUR established the appropriate technology and strategy to interrupt the transmission of Chagas disease.

  • (ii)

    A control programme

The Central American Initiative

IPCA was created to duplicate the success of the Southern Cone countries. IPCA, however, differs from INCOSUR in the following ways: (i) its creation was concurrent with decentralization of the health system; (ii) a smaller number of scientists with limited influence on political decisions are present in the region; and (iii) a widely distributed species of vector with domestic, peridomestic, and sylvatic populations is the main vector (Tri. dimidiata). The initiative had limited success during

Challenges in Central America

The collaboration between IPCA and the decentralized health system has revealed new challenges. While the elimination of R. prolixus in Central America will be attainable in the near future, the control of Tri. dimidiata remains a difficult task. The key challenges lie in efficient geographic coverage and sustainability. Central American countries require control activity that will produce maximum results with minimum investment. In addition, attaining sustainability is important to permit

Chagas Disease Control Initiatives in Other Regions

Beside the Southern Cone and Central American regions, crucial areas in the control of Chagas disease are the Andean and Amazon regions and Mexico.

Conclusion

Interruption of Chagas disease transmission in Central America by 2010, as proposed by IPCA, seems achievable, although the process of maintenance, especially with Tri. dimidiata, needs to be accelerated. The vector control technologies and strategy developed by INCOSUR were largely applicable to Central American conditions. There are, however, some Central American situations that challenge this vector control strategy: the rapid decentralization of the health system and residual and

Acknowledgements

This review was written as part of the regional effort to combat Chagas disease in the Americas in collaboration with stakeholders in Central and South American countries as well as with international organizations such as PAHO, JICA, ECLAT, CIDA, MSF, and World Vision. We thank the vector control teams of the Ministry of Health of Guatemala, El Salvador, Honduras, and other Central and South American countries for their pursuit of Chagas disease vector control. We also thank C. Cordon-Rosales,

References (86)

  • A. Aché et al.

    Interrupting Chagas disease transmission in Venezuela

    Revista do Instituto de Medicina Tropical de São Paulo

    (2001)
  • D. Akhavan

    Analise de Custo-efetividade do Programa de Controle da Doença de Chagas no Brasil

    (2000)
  • R. Carcavallo et al.

    Geographical distribution and Alti-latitudinal dispersion

  • R.A. Cedillos

    Chagas’ disease in El Salvador

    Bulletin of Pan American Health Organization

    (1975)
  • J. Costa et al.

    Ecologic niche modeling and differentiation of populations of Triatoma brasiliensis Neiva, 1991, the most important Chagas’ disease vector in northeastern Brazil (Hemiptera, Reduviidae, Triatominae)

    American Journal of Tropical Medicine and Hygiene

    (2002)
  • E. Dias

    Doenças de Chagas nas Américas III. Américas Central

    Revista Brasileira de Malariologia e Doenças Tropicais

    (1952)
  • J.C. Dias

    Controle de vetores de doença de Chagas no Brasil e riscos de reinfestação domiciliária por vetores secundários

    Memoria do Instituto Oswaldo Cruz

    (1988)
  • J.C. Dias

    Chagas disease control in Brazil: which strategy after the attack phase?

    Annales de Societe Belge de Medicine Tropicale

    (1991)
  • J.C. Dias et al.

    The evolution of Chagas disease (American trypanosomiasis) control after 90 years since Carlos Chagas discovery

    Memoria do Instituto Oswaldo Cruz

    (1999)
  • J.C. Dias et al.

    The impact of Chagas disease control in Latin America: a review

    Memoria do Instituto Oswaldo Cruz

    (2002)
  • J.P. Dujardin et al.

    The origin of Rhodnius prolixus in Central America

    Medical and Veterinary Entomology

    (1998)
  • F. Guhl

    Memoria del Primer Taller Internacional sobre Control de la Enfermedad de Chagas

    (2005)
  • F. Guhl et al.

    Proceedings of the ECLAT-AMCHA International Workshop on Chagas Disease Surveillance in the Amazon Region, Palmari, Brazil

    (2004)
  • K. Hashimoto et al.

    Effectiveness of health education through primary school teachers

    Technology and Development

    (2005)
  • R.J. Hayes et al.

    Estimación de las tasas de incidencia de infecciones y parasitosis crónicas a partir de la prevalecía: la enfermedad de Chagas en América Latina

    Boletín de la Oficina Sanitaria Panamericana

    (1990)
  • B. Liese et al.

    Organizing and Managing Tropical Disease Control Programs. Lessons of Success

    (1991)
  • J. Miller

    Chagas disease in Panama: report of three cases

    Southern Medical Journal

    (1931)
  • Informe para la Misión de Evaluación OPS/OMS

    (2003)
  • D.H. Molyneux et al.

    Oncocerciasis and Chagas’ disease control: the evolution of control via applied research through changing development scenarios

    British Medical Bulletin

    (1998)
  • A. Moncayo

    Chagas disease: current epidemiological trends after the interruption of vectorial and transfusional transmission in the Southern Cone countries

    Memoria do Instituto Oswaldo Cruz

    (2003)
  • C. Monroy et al.

    Assessing methods for the density of Triatoma dimidiata, the principal vector of Chagas’ disease in Guatemala

    Medical Entomology and Zoology

    (1998)
  • C. Monroy et al.

    Comparison of indoor searches with whole house demolition collections of the vectors of Chagas disease and their indoor distribution

    Medical Entomology and Zoology

    (1998)
  • C.M. Morel

    Chagas disease, from discovery to control – and beyond: history, myths and lessons to take home

    Memoria do Instituto Oswaldo Cruz

    (1999)
  • Programa de Prevención y Control de la Enfermedad de Chagas: Informe para Misión de Evaluación OPS/OMS

    (2002)
  • J. Nakagawa et al.

    Impact of residual spraying on Rhodnius prolixus and Triatoma dimidiata in the department of Zacapa in Guatemala

    Memoria do Instituto Oswaldo Cruz

    (2003)
  • J. Nakagawa et al.

    The impact of vector control on Triatoma dimidiata in the Guatemalan department of Jutiapa

    Annals of Tropical Medicine and Parasitology

    (2003)
  • J. Nakagawa et al.

    Geographic characterization of triatomine infestation in north-central Guatemala

    Annals of Tropical Medicine and Parasitology

    (2005)
  • A. Oliveira Filho

    Uso de nuevas herramientas para el control de triatominos en diferentes situaciones entomológicas en el continente americano

    Revista da Sociedade Brasileira de Medicina Tropical

    (1997)
  • Iniciativa del Cono Sur

    (1993)
  • Iniciativa de Salud del Cono Sur. VIIa. Reunión de la Comisión Intergubernamental para la Eliminación de Triatoma infestans y la Interrupción de la Tripanosomiasis americana por Transfusión

    (1998)
  • Iniciativa de Salud del Cono Sur. VIIIa. Reunión de la Comisión Intergubernamental para la Eliminación de Triatoma infestans y la Interrupción de la Tripanosomiasis americana por Transfusión

    (1999)
  • Primera Reunión de la Comisión Intergubernamental de la Iniciativa de Centroamérica y Belice para la interrupción de la Transmisión Vectorial de la Enfermedad de Chagas por Rhodnius prolixus, Disminución de la Ingestación Domiciliar por Triatoma dimidiata

    (1999)
  • Iniciativa de Salud del Cono Sur. IXa. Reunión de la Comisión Intergubernamental para la Eliminación de Triatoma infestans y la Interrupción de la Tripanosomiasis americana por Transfusión

    (2000)
  • Cited by (0)

    View full text