When travelling to such areas, it is very likely that one ingests Entamoeba histolytica and that it also settles in the colon. Most of the time, however, the infection runs its course without any symptoms. Nevertheless, cysts are excreted with the stool, which means that the germ is often passed on unnoticed.
Only in about 5 to 20% of cases do symptoms develop. A distinction is made between the intestinal and the extraintestinal type.
Amoebic dysentery of the intestinal type
If the parasite remains in the intestine and only damages it, a raspberry jelly-like diarrhoea occurs acutely. This is because the intestine tries to get rid of the pathogen as quickly as possible, which is why a lot of secretion and mucus is produced. The infection causes slight bleeding of the colon walls, which explains the typical colouring and consistency.
In addition to diarrhea, cramps and sometimes fever also occur. If the germ is not combated and the infection becomes chronic, such unpleasant intestinal inflammations sometimes recur over many years.
Amoebic dysentery of the extraintestinal type
If the germ cannot be kept in the large intestine, it migrates via the blood system to the liver and usually settles there. Several months or even years can pass before symptoms appear here. Then there are acute abscesses (encapsulated collections of pus) with a feeling of pressure and pain in the right upper abdomen. Sometimes the body temperature may rise slightly, but fever rarely occurs.
In very large abscesses of the liver, the thorax may also become constricted, which can lead mainly to pain and also breathing difficulties. In very rare cases, the parasite also settles in other organs, such as the brain, spleen or lungs.