Trypanocidal drugs for chronic asymptomatic Trypanosoma cruzi infection

Background Prevention of chronic chagasic cardiomyopathy (CCC) by treating infected populations with trypanocidal therapy (TT) remains a challenge. Despite a renewed enthusiasm for TT, uncertainty regarding its efficacy, concerns about its safety and limited availability remain barriers for a wider use of conventional drugs. We have updated a previous version of this review. Objectives To systematically search, appraise, identify and extract data from eligible studies comparing the outcome of cohorts of seropositive individuals to Trypanosoma cruzi exposed to TT versus placebo or no treatment. Search methods We sought eligible studies in electronic databases (Cochrane Central Register of Controlled Trials (CENTRAL), Issue 1, 2014); MEDLINE (Ovid, 1946 to January week 5 2014); EMBASE (Ovid, 1980 to 2014 week 6) and LILACS (up to 6 May 2010)) by combining terms related with the disease and the treatment. The search also included a Google search, handsearch for references in review or selected articles, and search of expert files. We applied no language restrictions. Selection criteria Review authors screened the retrieved references for eligibility (those dealing with human participants treated with TT) and then assessed the pre‐selected studies in full for inclusion. We included randomised controlled trials (RCTs) and observational studies that provided data on either mortality or clinical progression of CCC after at least four years of follow‐up. Data collection and analysis Teams of two review authors independently carried out the study selection, data extraction and risk of bias assessment, with a referee resolving disagreement within the pairs. Data collection included study design, characteristics of the population and interventions or exposures and outcome measures. We defined categories of outcome data as parasite‐related (positive serology, xenodiagnosis or polymerase chain reaction (PCR) after TT) and participant‐related (including efficacy outcomes such as progression towards CCC, all‐cause mortality and side effects of TT). We reported pooled outcome data as Mantel‐Haenszel odds ratios (OR) or standardised mean differences (SMD) along with 95% confidence intervals (CI), using a random‐effects model. I2 statistics provided an estimate of heterogeneity across studies. We conducted an exploratory meta‐regression analysis of the relationship between positive‐serology and progression of CCC or mortality. Main results We included 13 studies involving 4