Amoebiasis, caused by the microscopic parasite Entamoeba histolytica, a single-celled organism, is a very common intestinal infection in the tropical countries. Consuming water or food contaminated with the parasite can lead to this intestinal infection. While there are very few cases of amoebiasis in the developed world, the developing nations like India, Latin America, Africa, and Southeast Asia see several cases of amoebiasis every year. Amoebic dysentery is often confused with ‘traveller’s diarrhoea’, another widespread infection in the developing nations. But travellers’ diarrhoea is mainly caused by eating food contaminated with bacteria and on very few occasions the causative agents are parasites or viruses, while amoebic dysentery is caused by the protozoan, Entamoeba histolytica only.
The parasite exists in 2 forms: one is the motile form, which is not harmful, and the other is the cyst form, which causes the person-to-person transmission. The common mode of spread of the infection is the faecal-oral route and lack of adequate sanitation is the prime cause of transmission of amoebiasis. An infected person becomes responsible for spreading amoebiasis if his infected stool, in some way or the other, contaminates drinking water or food, which is further consumed by an healthy individual.
The symptoms may start showing five days to a week after the person has consumed food or water contaminated with the parasite. However, many of the times, there are very mild or no symptoms at all. The variation in the intensity of the infection depends upon the immune response of the infected person, strain of amoeba, and maybe associated viruses and bacteria. While diarrhoea and abdominal pain are the distinctive symptoms of amoebiasis, gradually, as the infection spreads, the person may feel cramps, nausea, and a loss of appetite; in some cases, fever and blood in stools are also seen. One may also develop dehydration and anaemia due to amoebic dysentery. If proper and timely treatment is not given to the patient, the infection may spread to the liver through the bloodstream, and may cause high fever and painful liver abscesses.
A stool test is conducted to diagnose the disease. As the human body also generates antibodies against the infection, a blood test may also be recommended to verify the presence of such antibodies in the blood. Antibiotics can cure amoebiasis completely, as they kill the parasite within first few days of treatment. Almost all patients make full recovery from this disease with proper drugs and treatment.
Amoebiasis can certainly be prevented. First and foremost, one must make it a point to drink clean, purified water and eat hygienically prepared food. One must strictly avoid eating raw vegetables, fruits, or salad without properly cleaning them. Maintaining personal and public hygiene is equally important so that the protozoan does not infect you and spread further.