By: Udiyana, MD
Amoebiasis is an illness transmitted when someone eats or drinks something that has been contaminated with a microscopic parasite, which is an amoeba (single-celled organism) called Entamoeba histolytica (E. histolytica). That is how the illness got its name: Amoebiasis. Amoebiasis commonly occurs in areas where living conditions are crowded and with a lack of sanitation. The illness is prevalent in some parts of the developing world, including Southeast Asia, Africa, South America, and India. Amoebiasis is contagious.
Wherever living conditions are unsanitary and hygiene is poor, the chances are higher that the infection will pass from one person to another. Amoebiasis spreads through contaminated food or water containing the cyst stage of the parasite. It can also spread by person-to-person contact. Amoebiasis can also spread among people who use shared objects but without adequate hand washing. In some cases, the parasite lives in a person’s colon without causing any symptoms. But sometimes, it invades the lining of the colon, causing stomachache, cramping, nausea, loss of appetite, bloody diarrhea, or fever. Rarely, the parasite will invade the body further than the intestines and causes a more serious infection, such as a liver, lungs, or brain abscess.
People at high risk of severe disease include pregnant women, immuno-compromised people and patients receiving corticosteroids. In some people, symptoms of amoebiasis can appear within days to weeks after consuming food or water contaminated by amoebas. In other people, symptoms of amoebiasis either take months to appear or never appear at all. Most people who are infected with amoebiasis have minimal or no symptoms. When someone gets ill, he experiences abdominal pain that begins gradually, along with frequent loose or watery bowel movements, cramps, nausea, and a loss of appetite. In some cases, it develops into a fever, and possibly, bloody stools. Some said the foul smell of the stool is specific.
Examination of stools under a microscope is the most common way to diagnose amoebiasis. Sometimes, several stool samples must be obtained because the number of amoeba excreted in the stool, which varies from time to time, may be too low to be detected from any single sample. Travelers with either asymptomatic E. histolytica infection or symptomatic E. histolytica disease should be treated if the organism can be proven to be E. histolytica. For asymptomatic infection, iodoquinol or paromomycin are the drugs of choice. For symptomatic intestinal infection and extraintestinal disease, treatment with metronidazole or tinidazole should be followed by treatment with iodoquinol or paromomycin.
Stool test re-evaluation is needed in 2 weeks and 3 months after taking the medicines completely to make sure that the parasite has been cleared out. Considering that amoebas may contaminate food and water, you can help preventing the illness by being cautious about what you eat and drink, especially in some developing countries. The most important precautions are careful hand washing after each toilet visit and proper disposal of sewage.