Chagas disease, caused by the multi-host zoonotic parasite Trypanosoma cruzi, was first identified in 1909 and has been endemic in the Americas for over nine millennia. 1 Many factors contribute to shaping the complex epidemiology of the disease, including environmental conditions, host and vector biology, human behaviour, socioeconomic/political determinants, control programmes, and possibly parasite genetics. 2 , 3 , 4 With seven genetically distinct “discrete typing units” (DTUs TcI to TcVI plus TcBat), T. cruzi is a remarkably diverse protozoan. 3 In recent decades, declining vector-borne transmission (due mainly to vector-control efforts and improved housing) and increasing prevalence in previously non-endemic settings (due mainly to international and rural-to-urban migration) have substantially modified the disease landscape. These changes pose new challenges for understanding transmission dynamics and disease burden and for devising effective control and prevention strategies. 5
Chagas disease primarily spreads to humans via blood-sucking true bugs of the subfamily Triatominae (Hemiptera: Reduviidae). 6 Of about 160 known species across five tribes and 18 genera, the most important vectors are several American species of Triatoma, Rhodnius, and Panstrongylus. 6 , 7 , 8 T. cruzi transmission cycles also involve over 150 domestic, synanthropic (i.e., living in close association with humans), and wild mammalian host species in at least eight orders—Didelphimorphia (opossums), Cingulata (armadillos), Pilosa (sloths, anteaters), Rodentia (rodents), Chiroptera (bats), Carnivora (e.g., dogs, cats), Artiodactyla (e.g., goats, pigs, donkeys), and Primates (monkeys and humans). 9 , 10 , 11 Transmission occurs primarily when a vector feeds on the blood of a susceptible mammal and releases faeces and/or urine containing infective forms of the parasite, which then enter the host through skin lesions or mucous membranes. 2 , 3 , 4 , 5 , 6 , 12 Human-vector contact is more frequent, and transmission more likely, when triatomine bugs stably infest houses. 6 Other transmission routes include blood transfusion, organ transplantation, consumption of infected food or beverages, and vertical transmission from mother to foetus; predation of infected triatomines may be a relevant infection route among non-human mammals ( Table 1 ). 2 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24.
Conce el artículo completo: The epidemiology of Chagas disease in the Americas - ScienceDirect