Chagas disease is one the WHO’s 17 designated neglected tropical diseases (NTDs). Its causative agent is the protozoan parasite Trypanosoma cruzi, predominantly spread by blood-sucking triatomine bugs which typically inhabit poorly-constructed rural dwellings in Latin America. Infection by the parasite leads to an acute phase, which can resemble other infections (with fever etc), and then a chronic phase which can last years or even decades. While most of those infected remain symptom-free, up to 40% will develop progressive organ damage, notably in the heart and gastrointestinal tract.
Despite a major reduction in Chagas cases in the last 20-30 years – achieved largely through WHO-led efforts at vector control and reduced transmission – Chagas is still estimated to affect some 6-8m people worldwide and it remains the leading cause of cardiac morbidity and mortality in rural and poor suburban areas of Latin America as well as a growing problem in other continents (through population migration). Current therapeutic options, benznidazole and nifurtimox, were introduced 40+ years ago and, while they are very effective at eradicating the parasite in the acute phase, their impact on indeterminate and chronic disease is not fully elucidated (indeed the recently reported BENEFIT study showed that benznidazole did not significantly reduce cardiac deterioration over 5 years). Furthermore they have important drawbacks (prolonged dosing, toxicity). New, more convenient and safer treatment options are needed.