Amebiasis or amoebic dysentery is a parasite enteral disease. It is caused by Entamoeba genus amoeba. It causes mild to severe symptoms like bloody diarrhea, abdominal discomfort, or no symptoms. This parasite may enter into the bloodstream and go to liver. This can lead to an amoebic hepatic abscess. Stool samples and blood tests are required to diagnose the disease. Amoebiasis can be found globally. It affects about 40,000 to 100,000 people per year.  

Amebiasis mostly occurs in underdeveloped countries because of poor sanitation and elevating fecal contamination to drinking water sources. Amebiasis is an ailment. It affects over 50 million people globally. Infected food or water consumption by feces which contains E. histolytica larvae can cause infection. E. histolytica can survive in environment for longer periods in its cyclic condition. It is also got by penetrative and anal sex, direct rectum inoculation or colon irrigation equipment. There are no vaccinations or preventative drugs for amebiasis. 

Protozoa infection of E. histolytica generates pseudopods and lyses tissue and causes proteolysis. Consuming mature cysts by feces contaminated hands, water, or food can lead to this condition. The small bowel goes excystation of the developed cysts and releases trophozoites. This can go to large bowel. Binary fission produces cysts as the trophozoites grow. Both stages exit via feces. The cysts can survive for days to 7 weeks in the environment.   

Amebiasis is caused by parasite Entamoeba histolytica. There are 3 different species of intestinal amoeba. Many symptomatic diseases occur by Entamoeba histolytica. Entamoeba dispar is not pathogenic. Entamoeba moshkovskii is more prevalent. It is now known it is pathogenic or not. The oral-fecal pathway is the way to proliferate. Contaminated food and water can cause infectious cysts. Rare cases of sexual transmission have been found. 

Amoebic infections have a very high risk of morbidity and mortality. Malaria can lead to death. 

The below demographics have the most severe amoebic infestations: 

Postpartum females 

People who are underweight 

Neonates 

Pregnant women 

People who take corticosteroids 

People who have malignancies 

The prognosis is good if the disease is treated. Infestations recurrence is common in many regions of the world. < 1% of patients die after the treatment. An intraperitoneal puncture may remove an amoebic abscess in 5 to 10% of cases. It increases the fatality rate. The fatality rate of amoebic pericarditis & bronchial amebiasis is about 20%. Fatality rate in patients who have uncomplicated diseases are below 1 % wit intense treatment. An infected amoebic hepatic disease is a significant disease which increases the mortality rate. 

Asymptomatic Infection: Many people who are infected with E. histolytica may have no symptoms, specifically in regions with endemic amoebiasis.  

Intestinal Amebiasis: 

• Mild to Moderate Disease: The common symptoms appear, like abdominal pain, cramping, and diarrhea. Loose stools with occasional blood and mucus can be present. They may have mild fever and weight loss.   
• Severe Disease: The severe infection is known as invasive amebiasis. The symptoms are like severe high fever and bloody diarrhea. Complications like toxic megacolon, colonic perforation, and extraintestinal spread can also occur. 
• Extraintestinal Amebiasis:  Extraintestinal amebiasis develops as a liver abscess. Symptoms are like right upper quadrant abdominal pain. Fever and enlarged liver. Patients who have cough and pleuritic chest pain in extension of infection to lungs. 

Age Group: 

This disease can affect all individuals from all ages. Severe complications commonly occurred in older adults and young children. 

• General Appearance: Check the overall appearance of patient of distress or dehydration. 
• Vital sign: Assess the vital signs of patient like heart rate, temperature, blood pressure, and respiratory rate.  
• Abdominal Examination: Palpate the abdomen for any tenderness or guarding. Check for enlargement of liver in cases of liver abscess. Check for any sign of peritonitis in severe cases.  
• Digital Rectal Examination (DRE): Perform a DRE to check for blood, tenderness, or mucus in rectum. Any presence of rectal ulcerations can be an invasive disease. 
• Skin Examination: Check for any sign of dehydration, like reduced skin turgor or dry mucus membranes. 
• Respiratory Examination: Check the respiratory system for signs of pleuropulmonary amebiasis. This can involve auscultation of lung and check for any signs of pleuritic chest pain. 
• Neurological Examination: Individuals who have amebic encephalitis may have neurological symptoms. Check for mental status, motor function, and cranial nerves.  
• Diagnostic Tests: Laboratory tests like stool examination for cysts and trophozoites can confirm the diagnosis. Imaging studies can be used to identify liver abscesses or any other complications.  

• Immune Status: Individuals who are immunocompromised or, have HIV or AIDS or taking immunosuppressive medications are at high risk of severe disease. 
• Malnutrition: Individuals with a lack of nutrition may be at more risk of severe amebiasis. 
• Travel to Endemic Areas: Travelers with poor sanitation and hygiene practice are at high risk of disease. 

The acuity of presentation may vary from mild to severe cases of disease. Seve cases may have acute abdominal pain, signs of systemic inflammation and high fever. 

Asymptomatic or Mild Intestinal Amebiasis: 

• First-Line Treatment:  A luminal amebicide is used to eliminate the parasite from lumen of intestine. Oral tinidazole or metronidazole are prescribed. 

Moderate to Severe Intestinal Amebiasis: 

• First-Line Treatment:  A tissue amebicide is added to the treatment to target the invasive form of parasite in colonic mucosa. Oral metronidazole or tinidazole and oral or IV diloxanide furoate or paromomycin is prescribed. Metronidazole or tinidazole is given for 7 to 10 days, and diloxanide furoate or paromomycin is given for 10 to 14 days.  
• Severe or Fulminant Amebic Colitis:  Severe cases may need hospitalization for IV fluids, supportive care, and close monitoring. IV metronidazole is also used in severe cases. If there is a perforation or severe colonic necrosis, surgery is needed in some cases.  

Extraintestinal Amebiasis (Liver Abscess): 

• First-Line Treatment:  The same medications are used in severe intestinal disease. IV metronidazole with oral treatment of metronidazole or tinidazole, along with luminal agents like diloxanide furoate or paromomycin, is used. The treatment may be long.  
• Follow-Up: Stool tests or serologic tests can be performed to confirm the results of treatment. Clinical and radiological monitoring is necessary specifically for extraintestinal manifestations. 

Emergency Medicine

Gastroenterology

Infectious Disease

Nutrition

• Hygiene and Sanitation: Proper hygiene can stop the transmission of infection. Wash your hands with water and soap, specifically after visiting the washroom and handling the food. Using clean and safe water sources will help to prevent the use of contaminated water. 
• Food Safety: Promote proper food handling technique to prevent contamination. Properly wash fruits and vegetables before the cooking and avoid eating raw or undercooked seafood. 
• Education and Awareness: Educate people in endemic area about the risk of disease and necessity for medical attention if the symptoms appear. 
• Nutritional Support: Proper nutrition is necessary for overall health and recovery. Promote a well-balanced diet with nutritional and digestible foods.  
• Rehydration: Maintain hydration is necessary, specifically is cases of dehydration and diarrhea. One can take oral rehydration to replace the lost fluids and electrolytes. 
• Rest and Symptomatic Relief: Individual who has amebiasis may have fatigue and weakness. Proper rest is necessary to recovery. Symptoms like stomach discomfort and fever can be managed by drugs. 
• Isolation and Infection Control: Proper isolation and prevention of infection must be adopted in hospital. This involves separate bathroom facility who have active infection, proper disposal of contaminated material and hygiene protocols by healthcare providers. 

Infectious Disease

Metronidazole is an important antimicrobial drug. It is used to treat amebiasis caused by Entamoeba histolytica. It inhibits synthesis of nucleic acid and causes cell death by interfering the structure of DNA. It is effective against both luminal and tissue forms of Entamoeba histolytica. It is available in forms of oral formulations and taken after the meal to improve absorption and reduce the stomach discomforts. 

Infectious Disease

Tinidazole is an antimicrobial drug. It is used to treat amebiasis. It disrupts the structure of DNA and function of microbial cells, inhibits the synthesise if nucleic acid and lead to cell death. It is effective against both luminal and tissue forms of Entamoeba histolytica. The dose of medication is dependent on the severity and symptoms of disease. The usual dosage id 2 gm per day for 2 to 3 days. 

Infectious Disease

Luminal agents like paromomycin and diloxanide furoate are used to treat amebiasis in luminal phase of Entamoeba histolytica. This medication is prescribed along with tissue amebicides like tinidazole or metronidazole. 

• Paromomycin: It is an aminoglycoside antibiotic. It interferes the synthesis of protein in the parasite and lead to death. It is used as a luminal agent to eliminate cyst and trophozoite form of Entamoeba histolytica in the intestine. It is administered orally. It is also administered IV in some cases. The dosage and duration is dependent on the severity of infection. It is prescribed for 7 to 10 days. 
• Diloxanide Furoate: It interferes with liminal forms of Entamoeba histolytica. It prevents cysts. It is used as a luminal agent to eliminate parasite in the intestine. It is prescribed along with tissue amebicide. It is administered orally in suspension form or tablets. The duration and dosage may vary. It is prescribed for 10 to 14 days. 

Surgical Intervention: 

• Perforation or Complications: Amebic colitis can lead to perforation of colon in some cases. This needs surgical intervention. It is needed in cases of extensive colonic necrosis or toxic megacolon. 
• Abscess Drainage: Liver Abscess: Large liver abscesses may need drainage specifically in patient who is not respond to the treatment well. Percutaneous drainage using imaging is common surgery. 
• Parasite Aspiration: Extraintestinal Spread: In cases where the amebic infection spreads to other organs like brain or lung, aspiration or drainage can be considered. 
• Colonoscopy or Sigmoidoscopy: Evaluation and Biopsy: Colonoscopy or sigmoidoscopy can be performed to check the extent of involvement of colon and to get biopsy samples to diagnose.  
• Supportive Care: Fluid Resuscitation: In severe cases of electrolyte imbalance and dehydration, IV fluid resuscitation is necessary. This can help to rehydration and electrolyte balance. 
• Nutritional Support: 
• Enteral or Parenteral Nutrition: In severe malnutrition and patient who are not able to take oral intake, enteral or parental nutrition can be provided to make sure of proper nutritional support. 

Critical Care/Intensive Care

Emergency Medicine

Nutrition

• Diagnostic Phase: Clinical Evaluation: Check the symptoms, medical history, and risk factors of patients for any exposure of Entamoeba histolytica.
  Laboratory Testing: Stool test for presence of trophozoites and cysts or serologic tests for antibodies against Entamoeba histolytica. 
• Acute Treatment Phase: Antimicrobial Therapy: Administration of pharmaceutical agents like metronidazole or tinidazole to treat this disease. In severe cases, IV metronidazole can be used.
  Combination Therapy: Tissue amebicides like tissue amebicides and luminal agents like paromomycin, diloxanide furoate both are used to make sure the complete elimination. 
• Supportive and Symptomatic Care Phase: Rehydration: Manage dehydration and electrolyte imbalance is necessary in cases of diarrhea and severe disease. 
  Nutritional Support: Provide proper nutrition is necessary for recovery. Enteral or parenteral nutrition is provided in some cases.  
• Monitoring and Follow-Up Phase: Clinical Monitoring: Regularly monitor the clinical status like symptoms and vital signs of patients. 
  Laboratory Follow-Up: Conduct follow up tests like stool tests or serologic tests to conform the complete removal of parasite and monitor the patient for any side effects of medications. 
• Preventive Phase: Health Education: Educate individuals in endemic area about the importance of sanitation, hygiene and safe food and water.
  Contact Tracing: Identify and avoid close contacts of individuals who have amebiasis to prevent transmission. 
• Long-Term Management and Prevention of Recurrence: Chronic Disease Considerations: Amebiasis may become chronic in some cases. Long-term management includes extended medications.
  Immunocompromised Individuals: Individuals who have compromised immune systems may need prolonged treatment.
  Health Maintenance: Emphasize preventive measures to avoid the recurrence of infections. 
• Special Populations: Pediatric Considerations: Adaptive treatment plans for pediatric patients with appropriate dosage depending on the weight is necessary.
  Pregnancy Considerations: Check the safety of medication during the pregnancy and adjust the treatment as per the requirements. 
• Surgical or Interventional Phase (if needed): Surgical Intervention: Surgery is needed in some cases, like liver abscess drainage, perforation, or toxic megacolon.