Chagas disease (American trypanosomiasis) is a zoonotic or anthropozoonotic disease caused by the parasite Trypanosoma cruzi. Predominantly affecting populations in poor areas of Latin America, medical care for this neglected disease is often lacking. Médecins Sans Frontières/Doctors Without Borders (MSF) has provided diagnostic and treatment services for Chagas disease since 1999. This report describes 10 years of field experience in four MSF programs in Honduras, Guatemala, and Bolivia, focusing on feasibility protocols, safety of drug therapy, and treatment effectiveness.
From 1999 to 2008, MSF provided free diagnosis, etiological treatment, and follow-up care for patients <18 years of age seropositive for T. cruzi in Yoro, Honduras (1999–2002); Olopa, Guatemala (2003–2006); Entre Ríos, Bolivia (2002–2006); and Sucre, Bolivia (2005–2008). Essential program components guaranteeing feasibility of implementation were information, education, and communication (IEC) at the community and family level; vector control; health staff training; screening and diagnosis; treatment and compliance, including family-based strategies for early detection of adverse events; and logistics. Chagas disease diagnosis was confirmed by testing blood samples using two different diagnostic tests. T. cruzi-positive patients were treated with benznidazole as first-line treatment, with appropriate counseling, consent, and active participation from parents or guardians for daily administration of the drug, early detection of adverse events, and treatment withdrawal, when necessary. Weekly follow-up was conducted, with adverse events recorded to assess drug safety. Evaluations of serological conversion were carried out to measure treatment effectiveness. Vector control, entomological surveillance, and health education activities were carried out in all projects with close interaction with national and regional programs.
Total numbers of children and adolescents tested for T. cruzi in Yoro, Olopa, Entre Ríos, and Sucre were 24,471, 8,927, 7,613, and 19,400, respectively. Of these, 232 (0.9%), 124 (1.4%), 1,475 (19.4%), and 1,145 (5.9%) patients, respectively, were diagnosed as seropositive. Patients were treated with benznidazole, and early findings of seroconversion varied widely between the Central and South American programs: 87.1% and 58.1% at 18 months post-treatment in Yoro and Olopa, respectively; 5.4% by up to 60 months in Entre Ríos; and 0% at an average of 18 months in Sucre. Benznidazole-related adverse events were observed in 50.2% and 50.8% of all patients treated in Yoro and Olopa, respectively, and 25.6% and 37.9% of patients in Entre Ríos and Sucre, respectively. Most adverse events were mild and manageable. No deaths occurred in the treatment population.
These results demonstrate the feasibility of implementing Chagas disease diagnosis and treatment programs in resource-limited settings, including remote rural areas, while addressing the limitations associated with drug-related adverse events. The variability in apparent treatment effectiveness may reflect differences in patient and parasite populations, and illustrates the limitations of current treatments and measures of efficacy. New treatments with improved safety profiles, pediatric formulations of existing and new drugs, and a faster, reliable test of cure are all urgently needed.
Chagas disease was discovered 100 years ago by the Brazilian physician Carlos Chagas. Predominantly affecting poor populations throughout Latin America, recognition and treatment of this parasitic disease are often neglected. Since 1999, the international medical humanitarian aid organization Médecins Sans Frontières (Doctors Without Borders) has offered diagnostic and therapeutic care for Chagas disease, and here we describe four of our programs in Honduras, Guatemala, and Bolivia, 1999–2008. The earliest programs focused on treating young children and in subsequent programs expanded up to 18 years of age. We identified six program components essential for project viability: information, education, and communication; vector control; health staff training; screening and diagnosis; treatment and compliance; and logistics. The number of children and adolescents screened for Chagas disease ranged from over 7,500 to nearly 25,000 in each program. Early analysis of cure rates ranged widely: from 87% and 58%, respectively, in Honduras and Guatemala, to 0%–5% in Bolivia. No deaths occurred in any of the programs, though drug-related side effects were observed in a quarter to half of all patients. Through our findings and experience, we discuss the feasibility, safety, and effectiveness of treatment programs for Chagas disease in resource-limited settings.