Amebic dysentery - Clinicals, Diagnosis, and Management

Infectious diseases

Clinicals - History

Fact Explanation
Cramping abdominal pain. Amoebae invade and penetrate the intact colonic mucosa and enter the submucosa, causing lysis and necrosis of its cells . This would result in colitis which would cause pain. Cramping abdominal pain.
Amoebae invade and penetrate the intact colonic mucosa and enter the submucosa, causing lysis and necrosis of its cells . This would result in colitis which would cause pain.
Blood and mucus diarrhoea. The mucosal invasion results in ulceraration, which is associated with an outflow of
tissue fluids, erythrocytes, neutrophils, lymphocytes, epithelial cells, etc, which gives rise to the blood and mucus nature of the diarrhoea .
Blood and mucus diarrhoea.
The mucosal invasion results in ulceraration, which is associated with an outflow of
tissue fluids, erythrocytes, neutrophils, lymphocytes, epithelial cells, etc, which gives rise to the blood and mucus nature of the diarrhoea .
Fever, anorexia, etc. it occurs as part of a systemic inflammatory response due to the lysis of tissue cells by
E. histolytica .
Fever, anorexia, etc.
it occurs as part of a systemic inflammatory response due to the lysis of tissue cells by
E. histolytica .
weight loss. This occurs as a result of the gradual onset of the disease . weight loss.
This occurs as a result of the gradual onset of the disease .
Gradual onset of disease. This helps to differentiate it from bacillary dysentery, which is of sudden onset . Gradual onset of disease.
This helps to differentiate it from bacillary dysentery, which is of sudden onset .
Rectal bleeding without diarrhoea. It can occur in some children when an amebic ulcer erodes a blood vessel . Rectal bleeding without diarrhoea.
It can occur in some children when an amebic ulcer erodes a blood vessel .
History of very high fever, severe abdominal bloating and pain, worse on movement. These are features of peritonitis which occur in the case of fulminant colitis. Peritonitis develops either because of frank perforation or a slow leak through an extensively diseased bowel . History of very high fever, severe abdominal bloating and pain, worse on movement.
These are features of peritonitis which occur in the case of fulminant colitis. Peritonitis develops either because of frank perforation or a slow leak through an extensively diseased bowel .
Symptoms lasting more than 2 weeks. Amebiasis is known to cause a chronic colitis . Symptoms lasting more than 2 weeks.
Amebiasis is known to cause a chronic colitis .

Clinicals - Examination

Fact Explanation
Lower abdominal tenderness. Amoebae invade and penetrate the intact colonic mucosa and enter the submucosa, causing lysis and necrosis of its cells . This would resulting colitis could cause peritoneal irritation. Lower abdominal tenderness.
Amoebae invade and penetrate the intact colonic mucosa and enter the submucosa, causing lysis and necrosis of its cells . This would resulting colitis could cause peritoneal irritation.
Febrile patient. It occurs as part of a systemic inflammatory response due to the lysis of tissue cells by
E. histolytica .
Febrile patient.
It occurs as part of a systemic inflammatory response due to the lysis of tissue cells by
E. histolytica .
Anthropometric examination revealing weight loss. This occurs as a result of the gradual onset of the disease . Anthropometric examination revealing weight loss.
This occurs as a result of the gradual onset of the disease .
Abdominal distention. It occurs in fulminant amebic colitis and frequently represents leakage through
a grossly intact colon rather than a discrete perforation .
Abdominal distention.
It occurs in fulminant amebic colitis and frequently represents leakage through
a grossly intact colon rather than a discrete perforation .
Rebound tenderness. This is a warning sign of peritonitis and indicates that perforation of the colon may have occurred . Rebound tenderness.
This is a warning sign of peritonitis and indicates that perforation of the colon may have occurred .

Investigations - Diagnosis

Fact Explanation
Leukocytosis in full blood count and an elevated erythrocyte sedimentation rate. A systemic inflammatory response occurs due to the lysis of tissue cells by
E. histolytica .
Leukocytosis in full blood count and an elevated erythrocyte sedimentation rate.
A systemic inflammatory response occurs due to the lysis of tissue cells by
E. histolytica .
Microscopic examination of fresh stool smears revealing trophozoites that contain ingested red blood cells. The motile form of E. histolytica, the trophozoite, lives in the lumen of the large intestine and has the ability to invade the colonic mucosa . The trophozoites can differentiate in to cysts (the infective form), which will be then excreted in stool. Microscopic examination of fresh stool smears revealing trophozoites that contain ingested red blood cells.
The motile form of E. histolytica, the trophozoite, lives in the lumen of the large intestine and has the ability to invade the colonic mucosa . The trophozoites can differentiate in to cysts (the infective form), which will be then excreted in stool.
Enzyme-linked immunosorbent assay (ELISA) to detect antigens from E. histolytica in stool. Galactose-inhibitable lectin of E. histolytica is a highly conserved antigen. Detection of amoebic lectin antigen in faeces using epitope-specific monoclonal antibodies provides a quantitative method for differentiating E. histolytica from E. dispar. The sensitivity and specificity of this assay is also high . Enzyme-linked immunosorbent assay (ELISA) to detect antigens from E. histolytica in stool.
Galactose-inhibitable lectin of E. histolytica is a highly conserved antigen. Detection of amoebic lectin antigen in faeces using epitope-specific monoclonal antibodies provides a quantitative method for differentiating E. histolytica from E. dispar. The sensitivity and specificity of this assay is also high .
Serum antilectin immunoglobulin G (IgG) antibodies detected using ELISA. They are present within 1 week after onset of symptoms in over 95% of patients . But they may be persistent for years so differentiation between past and present infection is difficult. Serum antilectin immunoglobulin G (IgG) antibodies detected using ELISA.
They are present within 1 week after onset of symptoms in over 95% of patients . But they may be persistent for years so differentiation between past and present infection is difficult.
Colonoscopy to diagnose amebic colitis. It is used when antigen tests are negative. It can be used to detect motile trophozoites using material aspirated or scraped from the base of ulcers. Also, biopsy specimens obtained could be stained with Periodic acid–Schiff, which stains the parasites a magenta color, increasing the ease of detection . Colonoscopy to diagnose amebic colitis. It is used when antigen tests are negative.
It can be used to detect motile trophozoites using material aspirated or scraped from the base of ulcers. Also, biopsy specimens obtained could be stained with Periodic acid–Schiff, which stains the parasites a magenta color, increasing the ease of detection .
Stool examination revealing occult blood. The mucosal invasion results in ulceraration, which is associated with an outflow of
tissue fluids and erythrocytes .
Stool examination revealing occult blood.
The mucosal invasion results in ulceraration, which is associated with an outflow of
tissue fluids and erythrocytes .

Investigations - Management

Fact Explanation
Reduced hemoglobin levels in full blood count. The mucosal invasion results in ulceraration, which is associated with a outflow of tissue fluids and erythrocytes . This blood loss would result in anemia. Reduced hemoglobin levels in full blood count.
The mucosal invasion results in ulceraration, which is associated with a outflow of tissue fluids and erythrocytes . This blood loss would result in anemia.

Management - Supportive

Fact Explanation
Adoption of preventive measures: -Boiling of water before drinking. -Washing of raw vegetables and soaking them in vinegar before consumption. Prevention of amebiasis requires interruption of the fecal-oral spread of the infectious cyst stage of the parasite . Adoption of preventive measures: -Boiling of water before drinking. -Washing of raw vegetables and soaking them in vinegar before consumption.
Prevention of amebiasis requires interruption of the fecal-oral spread of the infectious cyst stage of the parasite .

Management - Specific

Fact Explanation
Metronidazole. 750 mg, 3 times a day, for 5-10 days given orally. it is a tissue amebicide that is readily absorbed in to the blood stream. Therefore it is useful for intestinal invasive disease . Therapy with metronidazole is usually followed by a luminal agent. Metronidazole. 750 mg, 3 times a day, for 5-10 days given orally.
it is a tissue amebicide that is readily absorbed in to the blood stream. Therefore it is useful for intestinal invasive disease . Therapy with metronidazole is usually followed by a luminal agent.
Paromomycin. 10-day course at 30 mg/kg per day. It is given usually to treat asymptomatic infection. It is a luminal amebicide . Paromomycin. 10-day course at 30 mg/kg per day. It is given usually to treat asymptomatic infection.
It is a luminal amebicide .
Surgical interventions. Surgery is needed in instances where complications such as colonic perforation occur in cases of fulminant colitis . Surgical interventions.
Surgery is needed in instances where complications such as colonic perforation occur in cases of fulminant colitis .

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