Clinical Presentation in Humans:

On average, 90% of people who are infected with E. histolytica are asymptomatic. However, some strains of E. histolytica are able to invade the gut wall (thus damaging the walls of the large intestine, causing ulceration and subsequent bleeding) leading to the 10% of clinical cases that express symptoms ranging from mild to severe [9]. If the parasites gain access to damaged blood vessels, they could be carried to various extraintestinal sites in the body, most importantly, the liver (where the amoeba cause hepatic amoebiasis) [6]. 

Mild symptoms include:

Severe symptoms include:

[11, 12, 13]

Gross Pathology of amoebic liver abscess [23]

The parasite can also spread to other parts of the body, such as the lungs or brain, though this is less common [6]. Jaundice may occur, although very rare.  As well, the amoebic liver abscesses may also be presented as pyrexia (high fever) of unknown origin.  A further harm is that the abscesses can sometimes rupture into the pleural, peritoneal or pericardial cavities. [11].  Extrahepatic amebic abscesses are sometimes seen in regions of the lung, brain and skin, and are probably due to hematogenous spread as well [3]. Some of these symptoms eventually lead to weight loss [12]


[21]: Patient with amoebiasis liver absess, with perforation of abscess through abdominal skin.


[25]: dysentery showing diffuse ulceration of mucosa