Amoebic dysentery (amoebiasis) is caused by Entamoeba histolytica.

Amoebic dysentery, also known as amoebiasis, is a parasitic infection that affects the intestines. It is caused by the protozoan parasite Entamoeba histolytica. This parasite is commonly found in areas with poor sanitation and contaminated water. It can also be transmitted through the consumption of food or water contaminated with the cysts of the parasite.

Mode of Transmission:
The primary mode of transmission of Entamoeba histolytica is through the ingestion of contaminated food or water. The parasite exists in two forms: a cyst and a trophozoite. The cyst is the dormant stage of the parasite that can survive outside the body for a long time. When a person ingests the cyst, it passes through the stomach and reaches the intestines, where it transforms into the active trophozoite form. The trophozoites then multiply and invade the intestinal lining, causing inflammation and destruction.

Pathogenesis:
Once the trophozoites invade the intestinal lining, they can cause a range of symptoms ranging from mild diarrhea to severe dysentery. The trophozoites feed on the intestinal cells, causing ulceration and tissue destruction. They can also penetrate the intestinal wall and enter the bloodstream, leading to extra-intestinal manifestations such as liver abscesses.

Symptoms:
The symptoms of amoebic dysentery include:
- Diarrhea (often bloody)
- Abdominal pain and cramping
- Fatigue
- Weight loss
- Fever
- Nausea and vomiting

Diagnosis:
The diagnosis of amoebic dysentery involves the detection of the parasite in stool samples. Microscopic examination of the stool can reveal the presence of Entamoeba histolytica trophozoites or cysts. In some cases, a blood test may be performed to detect antibodies against the parasite.

Treatment and Prevention:
Amoebic dysentery can be treated with specific anti-parasitic medications that target Entamoeba histolytica. These medications can help eliminate the parasite from the intestines and alleviate the symptoms. It is also important to maintain good personal hygiene and avoid consuming food or water from unreliable sources to prevent the transmission of the infection.

In conclusion, amoebic dysentery is caused by the protozoan parasite Entamoeba histolytica. It is transmitted through the ingestion of contaminated food or water and can cause a range of gastrointestinal symptoms. Prompt diagnosis and treatment are essential to manage the infection effectively.