Amoebiasis is an infection of gastrointestinal tract caused by an intestinal parasite called Entamoeba histolytica. It causes dysentery, liver abscess and rarely affects lungs, heart and brain. It occurs everywhere in the world but especially in the areas where there is poor sanitation and poor socioeconomic status. The disease is transmitted through ingestion of the cyst through contaminated (with infected feces) food or water and invades the intestinal wall later to cause bloody diarrhea.

Giardia is a condition of gastrointestinal tract caused by an intestinal parasite called Giardia lamblia (also known as Giardia intestinalis or Giardia duodenalis). It is common at all ages but especially in younger children, in areas with poor sanitation and poor economic condition. The infection is transmitted through feco-oral route; through contaminated or uncooked food and through contaminated (with infected feces) water.

Amoebic and Giardia cyst are not killed by standard chlorination of drinking water.

Risk Factors

Amoebiasis and Giardiasis share many of the following risk factors:

• Young age
• Cancer
• Malnutrition
• Alcohol consumption
• Treatment with steroid
• Pregnancy
• Poor sanitation
• Men who have sex with men
• Migrants (in developed country)

Symptoms

Most people infected with Entamoeba or Giardia do not have symptoms.

Amoebiasis develops usually over one to three weeks. The symptoms could be:

Intestinal:

• Mild diarrhea to severe diarrhea and dysentery
• Blood in stool without diarrhoea
• Abdominal pain
• Fever
• Loss of appetite and Weight loss
• Perforation and peritonitis
• Anemia
• Lump (ameboma) might develop in the wall of intestine due to inflammation (seen on Colonoscopy)

Extraintestinal:

• Liver: fever, right upper abdominal pain, jaundice, enlarged liver
• Lungs: cough, chest pain, difficulty breathing
• Brain: headache, confusion, nausea and vomiting

The symptoms of Giardiasis could be:

• Sudden onset of diarrhea but not bloody; may continue for more than a week and sometimes longer
• Fatty and smelly bowel movements
• Abdominal cramps, distention
• Nausea and vomiting
• Chronic giardiasis can lead to weight loss and vitamin deficiencies

Red flags/When to seek care?

• When you have symptoms of amoebiasis or giardiasis noted above
• Unable to drink enough liquids
• Low urine output
• In addition, you have weak immune system, examples- chronic kidney disease, transplant recipient, on cancer treatment or steroids.

Diagnosis

History and physical exam with one or more of the following tests help establish the diagnosis:

• Stool microscopy for both giardia and amoeba.
• Blood tests: serology and antigen detection in blood, blood test to look for anemia, Liver function test
• Imaging: Ultrasound, CT scan to detect liver abscess
• Colonoscopy with histological examination to detect the parasite in intestinal lining
• Identification of cyst or trophozoite in drained pus from liver abscess.

Treatment

Amoebiasis: treatment is recommended even if you have no symptoms to prevent the complications and spread to others.

Giardiasis: asymptomatic person usually do not need treatment unless there is potential for spread to certain population like pregnant women or person with weak immune system.

• Antibiotics: metronidazole, tinidazole are the commonly used medicines to treat amebiasis and giardiasis. In addition Paromomycin or diloxanide furoate is used in amoebiasis to treat the cyst passers.
• Surgery: If a very large amoebic liver abscess develops, or antibiotic treatment is not successful, drainage of abscess may be needed.
• Fluid replacement: You might be dehydrated soon if you do not replace the fluid lost due to watery diarrhea. You should drink oral rehydration solution, at least 200 ml after each episode of diarrhea to prevent yourself from dehydration.
• Diet: Try to eat normally small and frequent meals although your appetite may have decreased

Prevention

• Pay special attention to personal hygiene, hand washing especially after using toilet, changing nappies of babies, before preparing, serving or eating food.
• You should wash the fruits and vegetables properly before eating.
• Keep your surroundings clean and maintain sanitation to reduce the risk of transmission of the worms to human.
• Drink only purified water when at home or travelling
• Do not share towels or clothes with others, do not prepare or serve food, regularly disinfect the toilet if you are infected.
• You should take time off from work or school until you are suggested to return by your doctor. Avoid contact with other people as far as possible.
• Avoid swimming when you have diarrhea.
• Avoid sexual activity during illness.