Amoebiasis
What is Amoebiasis?
Amoebiasis is an infection caused by a parasite called Entamoeba histolytica. This microscopic organism lives in contaminated water and food. When you swallow it, the parasite travels to your intestines and can cause digestive problems.
Most people who carry the parasite never develop symptoms. They remain healthy carriers who can spread the infection to others. However, some people develop intestinal amoebiasis with stomach pain and diarrhea. In rare cases, the parasite moves beyond the intestines to create abscesses in the liver, lungs, or brain.
Amoebiasis affects about 50 million people worldwide each year. It is most common in tropical countries with poor sanitation. The infection spreads through contaminated food, water, or direct contact with infected stool. Early detection through stool testing helps prevent serious complications.
Symptoms
- Watery diarrhea with blood or mucus
- Stomach cramping and pain
- Nausea and vomiting
- Fever and chills
- Weight loss from ongoing diarrhea
- Abdominal tenderness when touched
- Fatigue and weakness
- Gas and bloating
- Painful bowel movements
- Liver pain if an abscess forms
About 90 percent of people infected with Entamoeba histolytica never experience symptoms. They carry the parasite without knowing it. Symptoms usually appear 1 to 4 weeks after exposure. Some people develop mild symptoms that come and go over months or years.
Concerned about Amoebiasis? Check your levels.
Screen for 1,200+ health conditions
Causes and risk factors
Amoebiasis happens when you swallow the Entamoeba histolytica parasite. The parasite forms protective cysts that survive outside the body for weeks or months. These cysts contaminate drinking water, food, and surfaces in areas with poor sanitation. You can get infected by drinking untreated water, eating raw vegetables washed in contaminated water, or touching your mouth with contaminated hands.
Risk factors include living in or traveling to tropical countries with poor water treatment. People who handle food without proper handwashing can spread the infection. Men who have sex with men face higher risk due to possible fecal contact. People with weakened immune systems develop more severe infections. Crowded living conditions and institutional settings also increase exposure risk.
How it's diagnosed
Doctors diagnose amoebiasis by testing your stool for the presence of Entamoeba histolytica parasites or their eggs. This test is called an ova and parasites exam. You typically provide 3 separate stool samples collected on different days. The lab examines the samples under a microscope to identify the parasite. Some labs also use special tests that detect parasite DNA or proteins.
If you have symptoms of amoebiasis or recently traveled to a high-risk area, talk to your doctor about testing. Blood tests can detect antibodies your body makes against the parasite. Imaging tests like ultrasound or CT scans help find abscesses in the liver or other organs. Early diagnosis prevents the infection from spreading beyond your intestines.
Treatment options
- Prescription antiparasitic medications like metronidazole or tinidazole to kill the active parasite
- Follow-up medication like paromomycin or iodoquinol to clear parasites from the intestines
- Drinking plenty of fluids to prevent dehydration from diarrhea
- Eating bland, easy-to-digest foods during recovery
- Rest to help your body fight the infection
- Avoiding alcohol during treatment as it interacts with some medications
- Practicing careful handwashing to prevent spreading the infection
- Repeat stool testing after treatment to confirm the parasite is gone
- Drainage or surgery for liver abscesses in severe cases
- Medical care right away if you develop severe abdominal pain or high fever
Frequently asked questions
Amoebiasis is caused specifically by the Entamoeba histolytica parasite. The diarrhea often contains blood or mucus and develops gradually over days or weeks. Other types of diarrhea from bacteria or viruses usually start suddenly and resolve within a few days. Amoebiasis can persist for weeks or months without treatment and may cause liver abscesses.
Some mild cases may improve without treatment, but the parasite often remains in your intestines. You can continue spreading the infection to others even without symptoms. Untreated amoebiasis can cause serious complications like liver abscesses or spread to other organs. Doctors recommend treatment for all confirmed infections to prevent complications and transmission.
Get tested if you have persistent diarrhea with blood or mucus, especially after traveling to tropical areas. Testing is also important if you have ongoing stomach pain, unexplained weight loss, or fever lasting more than a few days. People who handle food professionally or live in institutional settings should get tested if exposed to someone with confirmed amoebiasis.
Yes, amoebiasis spreads through contact with infected stool. Family members can get infected by touching contaminated surfaces, sharing bathrooms, or through food prepared by someone with poor hand hygiene. Careful handwashing after using the bathroom and before preparing food prevents household transmission. Clean bathroom surfaces regularly with disinfectant when someone in your home has amoebiasis.
Treatment typically lasts 10 to 20 days depending on the severity of infection. Your doctor will prescribe an initial medication to kill active parasites, usually taken for 5 to 10 days. A second medication often follows to clear any remaining parasites from your intestines. You should feel better within a few days of starting treatment, but finish all medications as prescribed.
Municipal water in the United States is treated to remove parasites and is generally safe to drink. Amoebiasis from tap water is extremely rare in developed countries with modern water treatment systems. However, you should avoid drinking untreated water from wells, streams, or lakes. When traveling to countries with poor sanitation, drink only bottled or boiled water.
Avoid raw vegetables and fruits you cannot peel when traveling to high-risk areas. Skip ice cubes made from tap water in countries with poor sanitation. Do not eat food from street vendors where handwashing facilities may be limited. At home, wash all produce thoroughly and practice good food safety. Cook food to proper temperatures to kill parasites.
Most people recover fully with proper treatment and experience no lasting intestinal damage. Severe infections can occasionally cause intestinal scarring or chronic inflammation. Liver abscesses may leave scar tissue even after healing. Early treatment significantly reduces the risk of permanent damage or complications.
Having amoebiasis does not provide lasting immunity against future infections. You can get infected again if exposed to the parasite. Your body does produce antibodies during infection, but these do not prevent reinfection. Continue practicing good hygiene and safe food and water habits even after successful treatment.
Yes, doctors often recommend testing all household members when someone is diagnosed with amoebiasis. Asymptomatic carriers can spread the infection without knowing they have it. Testing helps identify and treat all infected family members to stop transmission. This is especially important if anyone in the household prepares food for others.