Chagas disease is found mainly in Latin America but now also in immigrant communities in the USA, Europe and elsewhere. Chronic Chagas can remain silent for decades, while causing organ damage that can lead to fatal heart failure. Evidence of parasites in this phase is critical both for diagnosis and for assessing if treatment worked. TDR coordinated work that has led to standardizing PCR (polymerase chain reaction) for diagnosis, and is now working with the Pan American Health Organization, Drugs for Neglected Diseases initiative, and various researchers and institutions to standardize an improved type of PCR (quantitative real-time PCR) to see if it can be used as a marker of treatment outcome for Chagas disease. In this context, TDR is contributing to a large Chagas treatment trial conducted in Latin America (BENEFIT).