# Food and Drinking Water as Sources of Pathogenic Protozoans: An Update
## 10 Trypanosoma cruzi  
_Trypanosoma cruzi_ is a flagellated protozoan of the clade Discoba [2], phylum Euglenozoa, family Trypanosomatidae, that causes Chagas disease (CD), an infection endemic in Latin America that can be severe and lead to disability and death. Among the transmission mechanisms, the oral route is the most important for the maintenance of the zoonotic cycle of the parasite [251]. Confirmed human cases of transmission through food were reported in Brazil, Bolivia, Ecuador, Venezuela, Colombia, Argentina, and French Guiana and mostly attributed to unpasteurized fruit juices, fruits, and other food and water infected with feces of triatomine (Triatomine subfamily, Hemiptera, Reduviidae) vectors of the parasite or with secretions of animal reservoirs [251]. The genera _Triatoma, Rhodnius_, and _Panstrongylus_ are the most epidemiologically relevant vectors of _T. cruzi_[12]. The infection can also be acquired by ingesting the raw meat of infected animals containing metacyclic trypanastigotes. These are the infective forms of the parasite and, in oral infection, enter the bloodstream through the mucosal membranes after binding to the gastric epithelium, a process modulated by glycoproteins gp82 and gp90. The metacyclic trypanastigotes are covered with mucin-like molecules that make them highly resistant to proteolysis in the gastric tract. In the host cell, the trypanastigotes transform into proliferative forms, the amastigotes, that multiply by binary division. These burst the host cells, infecting other cells and entering the bloodstream thus reaching many organs. In oral infection, the intensity of the inflammatory response depends on the parasitic load and determines mild or severe gastrointestinal manifestations [252]. _T. cruzi_ is classified into at least seven discrete typing units (DTUs), Tcl to TcVI, and Tcbat. Tcl is the most common DTU found in oral outbreaks and is associated with severe cardiopathy, while TcII, TcV, and TcVI--also associated with cardiopathy--give milder or no symptomatology. DTUs related to oral outbreaks in Brazil, Colombia, Venezuela, Bolivia, and French Guiana were TcI, TcV, TcIII, and TcIV [253]. TcI presents an extensive genetic diversity and is divided, according to the transmission route, into domestic (TcIDom) and sylvatic (TcISylv) genotypes. Methods for DTU distinction are specific PCR on genetic markers, including the spliced-leader intergenic region (SL-IR), microsatellites, kinetoplast DNA (kDNA), heat shock proteins (HSP), 18S rRNA gene, cytochrome c oxidase subunit 2 (COII), cytochrome b (Cytb), Glycosphosphatidylolipid (GPI) and 24S\(\alpha\) rDNA/rDNA subunits (24S\(\alpha\)). Older PCR-RFLP methods are still in use. A map of DTU distribution in different countries of parasites isolated from clinical samples, insects and food is available [254]. _Epidemiology and Symptoms of T. cruzi Infection_  
A meta-analysis of 2,470 orally-transmitted acute CD cases that resulted in 97 deaths in Venezuela, Colombia, Bolivia, French Guiana, and Brazil, showed that the food source was unreported in many studies. However, acai was the most common, followed by sugar cane juice, palm, mayo fruits, mango, orange, and other juices. Meta-regression showed that the lethality displayed a statistically significant reduction over the years, reflecting increased awareness, more rapid diagnosis, and prompt appropriate therapy [251]. Inadequate hygiene in food preparation at home caused CD in many instances, as in a recent outbreak in southwest Amazonas that involved 27 individuals who consumed acai juice prepared by a single person in a house with a palm leaf roof, amid palm trees, which are typical habitats for triatomines. Five of the exposed individuals had a confirmed diagnosis of CD and all had prolonged fever after a few days from ingestion of the juice. Symptoms, such as lower limb and face edema, headache, abdominal pain, vomiting, back pain, polyarthalgia, asthenia, carantenna, retro-orbital pain, generalized rash, and itching, were variable.