Amoebic Dysentery is caused by Entamoeba histolytica which lives in the lumen of large intestine of a human being as harmless minuta forms. When the resistance of gut is lowered in infected people, these become pathogenic, change to magna forms and invade the intestinal wall. They make their way deep into sub- mucosa by eating through mucosa of the intestinal wall. Here Entamoeba multiply by binary fission and spread radically outward to form flask shaped ulcers containing cellular debris, lymphocytes, blood corpuscles and bacteria. This results in the formation of abscesses in intestinal wall. As the sub mucosa is eroded, the ulcers burst and blood capillaries rupture. The blood and the ulcer contents (mucus, cell debris, blood corpuscles, bacteria and amoebae) pour into the lumen of intestine and pass with stool. This characterizes the amoebic dysentery or amoebiasis.
Symptoms of Amoebic Dysentery
The stool of a dysenteric person is usually acidic and consist swarms of Entamoebae as well. A person suffering from amoebic dysentery has repeated blood mixed, slimy and foul – smelling motions and is confined to the lavatory. Stomach cramps (colic), painful passage of stools (tenesmus), frequent loose stools, abdominal pain, cramps, fatigue, intermittent constipation, diarrhoea with abdominal swelling, flatulence are several other symptoms of amoebic dysentery.
Sometimes, the Entamoeba makes its way through blood circulation, into the brain, liver, spleen, lungs and gonads. Here also they destroy the tissues and cause formation of abscesses, or cavities containing pus. The affected liver becomes enlarged, congested and painful to touch. This pathological condition is referred to as amoebic hepatitis. Formation of abscesses in lungs and brain usually prove fatal in case of amoebic dysentery.
Causes of Amoebic Dysentery – Modes of Transmission
The transmission of Entamoeba occurs mainly by ingestion of cysts in contaminated food or drinks and causes amoebic dysentery. The food or drinks are contaminated by:
- Unhygienic habits of food handlers who by habit scratch the anus and then put the fingers in food which they serve.
- Habit of defecating in open fields cause contamination of vegetables and then washing the bottom in ponds causing contamination of water.
- Transmission of cysts from stools to food and drinks by flies and cockroaches.
Diagnosis of Amoebic Dysentery
The microscopical detection of trophozoites of entamoeba histolytica or the cysts in faecal smears is done to check the infection of amoebic dysentery. The presence of white, stone shaped ‘charcot-leyden’ crystals in faeces suggests the Entamoeba histolytica infection.
Treatment of Amoebic Dysentery
Treatment of amoebic dysentery is easy but permanent cure can’t be achieved as relapses do occur. For a temporary relief of amoebic dysentery, an alkaloid Emetine is effective. There is a synthetic derivative of Emetine called Dehydroemetine which is equally effective. The anti malarial drug, Chloroquine is effective against amoebic abscesses in the liver. Some iodine compounds such as Vioform, Chiniofon, Diodoquin, etc. and antibiotics such as Fumagilin, Terramycin, Erythromycin, Aueromycin are affective in eradication of Entamoeba histolytica. Metronidazole as an amoebicide is very active against intestinal and extra-intestinal amoebosis/amoebic dysentery.
Prevention of Amoebic Dysentery
Prevention from amoebic dysentery infection can be done by maintain a good hygiene. For the prevention from amoebic dysentery, these steps can be taken:
- Washing hands with soap and water after handling dirty articles, before taking meals and after using toilet.
- Cutting finger nails regularly.
- Avoiding the use of improperly washed vegetables and raw salads.
- Protection of foods and drinks from contamination by houseflies, cockroaches, etc.
- Avoiding passing stools in open fields and street sides etc.
- Avoiding eating from road side vendors and checking the food and surroundings before eating from a food handler.