Clinical Review Science, medicine, and the future

American trypanosomiasis (Chagas' disease) and the role of molecular epidemiology in guiding control strategies

BMJ 2003; 326 doi: http://dx.doi.org/10.1136/bmj.326.7404.1444 (Published 26 June 2003) Cite this as: BMJ 2003;326:1444
  1. Michael A Miles (michael.miles@lshtm.ac.uk), professor of medical protozoology1,
  2. M Dora Feliciangeli, head2,
  3. Antonieta Rojas de Arias, technical coordinator of vector control programmes3
  1. 1 Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT
  2. 2 Sección de Entomologia Medica, BIOMED, Universidad de Carabobo, Maracay, Venezuela
  3. 3 Instituto de Investigaciones en Ciencias de la Salud, Asuncion, Paraguay
  1. Correspondence to: M A Miles

    Chagas' disease is a parasitic infection that has far reaching consequences for public health and national economies in Latin America. The latest molecular typing methods may help in developing targeted, effective control programmes

    Fig 1

    Transmission cycles of Trypanosoma cruzi. (a) Enzootic transmission in the Amazon rainforest: no domestic colonies of triatomine bugs exist, but infrequent, sporadic cases of Chagas' disease may occur due to adult bugs flying to palm presses or houses, or when the triatomine species Rhodnius brethesi attacks workers sleeping in the forest to harvest piassaba palms. (b) An example of separate silvatic and domestic transmission cycles in Bahia state, Brazil: left, houses are infested by the triatomine bug Panstrongylus megistus; right, bromeliad epiphytes, refuges of the opossum (Didelphis albiventris), are infested by the triatomine bug Triatoma tibiamaculata. T cruzi II is found in the domestic cycle and T cruzi I in the silvatic cycle. (c) An example of overlapping silvatic and domestic transmission cycles in parts of Venezuela: the triatomine genus Rhodnius has several similar species; R prolixus may infest both houses and palms. Molecular analysis of triatomine vectors and T cruzi isolates shows where silvatic and domestic cycles are linked, which influences the design of control programmes (reproduced with permission from James Patterson)

    Fig 2

    Chagas' disease: clinical phases (reproduced with permission from James Patterson)

    Introduction

    In terms of public health and economic impact, American trypanosomiasis (Chagas' disease) is the most important parasitic infection in Latin America. More than 10 million people carry the protozoan agent Trypanosoma cruzi, which multiplies inside cells, particularly of heart and smooth muscle.1 In the chronic phase of infection up to 30% of infected people may develop severe abnormalities on the electrocardiogram and chagasic cardiomyopathy.2 Chagas' disease is a complex zoonosis, primarily transmitted by triatomine bugs, which infest poor …

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