# Food and Drinking Water as Sources of Pathogenic Protozoans: An Update
## 7 Entamoeba spp
### Diseases Caused by Entamoeba spp  
A few days after exposure to _E. histolytica_, infected individuals can show symptoms such as diarrhea and fever lasting 4-6 weeks. Some reports described infection manifestation years after exposure [187,188]. Symptoms similar to ulcerative colitis lasting for several months and IBS-like symptoms with abdominal pain and episodes of diarrhea alternated with constipation were also reported [187,189]. Severe forms of intestinal amoebiasis manifest with severe dysentery, fever above 38 \({}^{\circ}\)C, tachycardia, hypertension, nausea, and anorexia [190]. The mortality rate of dysenteric amoebiasis is less than 1%, but mortality due to complications increases up to 75%. Fulaminant necrotizing amoebic colitis, associated with large bowel gangrenous necrosis, perforation, and peritonitis with mucosal and submucosal ulcers, occurs in more than 50% of cases, with severe colitis representing 0.5-3% of _E. hystolitia_ infections. Other severe forms of _E. histolytica_ intestinal infectionsare colon amoeba and toxic megacolon. Intestinal amoebiasis is easily misdiagnosed as IBD and treated with steroids, thus increasing the possibility of severe complications [191]. Extra-intestinal infections may develop in some patients with severe outcomes that can be fatal. These include amoebic liver abscesses (ALA), which is the most common, peritonitis, venous thrombosis, lung abscesses/pneumonitis, hepatic encephalopathy, and pyopericardium/tamponade mediastitis which are direct or indirect complications of ALA rupture [183; 189; 192]. These severe forms can be observed in young children, pregnant women, the elderly, and immunocompromised subjects. Indeed, the destroyed host immunity, combined with tissue damage facilitates invasive amoebic infection, leading to a rapid progression of the disease [193]. The risk of ALA development is strongly associated with alcohol consumption [192]. ALA is a major parasitological health concern in northern Sri Lanka, where it is a common cause of emergency hospitalization. It was found to be associated with the consumption of the alcoholic fermented sap of the Palmyra toddy (_Borassus falbellifer_). This might be contaminated with _E. histolytica_ through water or unhygienic practices in preparation since cysts are resistant to low doses of chlorination [7]. Prevention could be accomplished by supplying safe drinking water, according to the WHO Guidelines for Drinking-Water Quality [194], and through safe consumption of alcoholic beverages [7]. Recent case reports of ALA regarded a 35-year-old man who also developed a right atrial thrombus that possibly originated from a hepatic vein thrombus [195] and a woman in early pregnancy seven years after a prolonged episode of intermittently blood diarrhea that she developed during a journey to Indonesia. In this case, infection with _E. histolytica_ was diagnosed by serological testing, while abscess fluid and blood were negative for the parasite [196]. ALA generally responds well to metronidazoleze treatment, and percutaneous catheter drainage is required in only 15% of ALA cases [197]. Other amoebicidal agents used to treat ALA include ornidazole, tinidazole, nitazoxanide, and chloroquine. At present, no vaccine exists to prevent _E. histolytica_-induced ALA [7]. Metronidazoleze treatment in invasive amoebiasis should always be followed by treatment with an agent able to eliminate cysts, such as paromomycin, to prevent relapse [195]. Three cases of infiltrative appendicitis caused by _E. histolytica_ were reported recently in a 59-year-old Indonesian man who necessitated hemicolectomy and recovered after treatment with metronidazoleze, in a 29-year-old woman, and in a 46-year-old man who was diagnosed post-operatively [198; 199; 199]. Amoebic appendicitis, if identified late, is associated with postoperative morbidity and mortality due to complications such as sepsis, ALA, postoperative colonic fistula, necrotic surgical site infection, necrotizing fasciitis, fulminant colitis, and brain abscess [199].