Dysentery (Enteroinvasive Escherichia coli)
Overview
Plain-Language Overview
Dysentery (Enteroinvasive Escherichia coli) is an infection that affects the large intestine, causing inflammation and damage to the intestinal lining. This condition leads to symptoms such as bloody diarrhea, abdominal pain, and fever. The infection is caused by a type of bacteria called enteroinvasive Escherichia coli (EIEC), which invades the cells lining the colon. The main health impact is the disruption of normal bowel function and fluid loss, which can lead to dehydration. It primarily affects the digestive system and can cause significant discomfort and illness.
Clinical Definition
Dysentery (Enteroinvasive Escherichia coli) is a form of invasive bacterial colitis characterized by the invasion and destruction of colonic epithelial cells by enteroinvasive Escherichia coli (EIEC). The pathogenesis involves bacterial penetration into the mucosa, leading to an intense inflammatory response and mucosal ulceration. This results in the hallmark clinical features of bloody diarrhea, abdominal cramps, and fever. EIEC shares pathogenic mechanisms with Shigella species, including the use of a type III secretion system to enter host cells. The disease is significant due to its potential to cause severe colitis and dehydration, especially in children and immunocompromised patients. Diagnosis and differentiation from other causes of dysentery are critical for appropriate management.
Inciting Event
Ingestion of contaminated food or water containing enteroinvasive E. coli initiates infection.
Fecal-oral transmission from infected persons or poor hygiene practices triggers disease.
Latency Period
Incubation period of 1 to 3 days typically precedes symptom onset after exposure.
Diagnostic Delay
Symptom overlap with other causes of dysentery such as Shigella or amoebiasis can delay diagnosis.
Lack of routine stool culture or molecular testing for enteroinvasive E. coli may lead to missed identification.
Empiric treatment without pathogen identification can obscure diagnosis.
Clinical Presentation
Signs & Symptoms
Frequent, small-volume bloody diarrhea with mucus is the hallmark symptom of enteroinvasive E. coli dysentery.
Abdominal cramps and pain often accompany the diarrhea.
Fever and chills are common systemic manifestations.
Tenesmus, or the sensation of incomplete defecation, is frequently reported.
Nausea and vomiting may occur but are less prominent.
History of Present Illness
Acute onset of bloody diarrhea with mucus and abdominal cramps is characteristic.
Fever and tenesmus often accompany the diarrhea.
Progression over several days with worsening abdominal pain and frequent stools is typical.
Nausea and vomiting may be present but are less prominent.
Past Medical History
Recent travel to endemic areas or history of consuming unsafe food or water is relevant.
Previous episodes of gastrointestinal infections may be reported.
Underlying immunosuppression or chronic illnesses can affect disease severity.
Family History
No significant heritable patterns or familial syndromes are associated with enteroinvasive E. coli dysentery.
Family members may share exposure risks due to common environment or hygiene practices.
Physical Exam Findings
Abdominal tenderness, especially in the lower quadrants, is common in dysentery caused by enteroinvasive Escherichia coli.
Signs of dehydration such as dry mucous membranes and decreased skin turgor may be present due to fluid loss.
Fever is often observed reflecting systemic inflammatory response.
Visible blood and mucus in stool can be noted during rectal examination.
Hyperactive bowel sounds may be heard early in the disease course due to intestinal inflammation.
Diagnostic Workup
Diagnostic Criteria
Diagnosis of dysentery caused by enteroinvasive Escherichia coli is established by identifying EIEC in stool cultures or by molecular methods such as PCR detecting invasion-associated genes. The presence of bloody diarrhea with leukocytes in stool supports the diagnosis. Colonoscopy may reveal mucosal ulceration and inflammation, but microbiological confirmation is essential. Differentiation from other invasive pathogens like Shigella is important for targeted therapy.
Pathophysiology
Key Mechanisms
Invasion of colonic epithelial cells by enteroinvasive Escherichia coli leads to mucosal ulceration and inflammation.
Intracellular multiplication of bacteria causes epithelial cell death and disruption of the mucosal barrier.
Inflammatory response with neutrophil infiltration results in bloody diarrhea and dysentery symptoms.
Tissue destruction and ulcer formation contribute to abdominal pain and tenesmus.
| Involvement | Details |
|---|---|
| Organs | Colon is the primary organ involved, where enteroinvasive Escherichia coli invades and causes bloody, inflammatory diarrhea. |
| Tissues | Colonic mucosa is the main tissue affected, showing ulceration, inflammation, and infiltration by immune cells in dysentery. |
| Cells | Colonic epithelial cells are the primary site of invasion and destruction by enteroinvasive Escherichia coli, leading to mucosal ulceration. |
Neutrophils infiltrate the colonic mucosa as part of the acute inflammatory response causing purulent diarrhea. | |
Macrophages participate in phagocytosis of bacteria and release proinflammatory cytokines amplifying tissue damage. | |
| Chemical Mediators | Interleukin-8 (IL-8) is secreted by infected epithelial cells to recruit neutrophils to the site of infection. |
Tumor necrosis factor-alpha (TNF-α) mediates inflammation and contributes to mucosal injury in dysentery. | |
Prostaglandins increase intestinal secretion and motility, exacerbating diarrhea. |
Treatments
Pharmacological Treatments
Fluoroquinolones
- Mechanism:
Inhibit bacterial DNA gyrase and topoisomerase IV, preventing DNA replication in Escherichia coli.
- Side effects:
Tendonitis
Gastrointestinal upset
QT prolongation
- Clinical role:
First-line
Trimethoprim-sulfamethoxazole
- Mechanism:
Inhibits sequential steps in bacterial folate synthesis, leading to bactericidal activity against E. coli.
- Side effects:
Rash
Hyperkalemia
Bone marrow suppression
- Clinical role:
First-line
Azithromycin
- Mechanism:
Binds to the 50S ribosomal subunit, inhibiting bacterial protein synthesis in E. coli.
- Side effects:
Gastrointestinal upset
QT prolongation
Hepatotoxicity
- Clinical role:
Second-line
Non-pharmacological Treatments
Oral rehydration therapy to prevent dehydration from diarrhea and fluid loss.
Avoidance of anti-motility agents to prevent worsening of invasive infection.
Nutritional support with continued feeding to maintain gut integrity and immune function.
Prevention
Pharmacological Prevention
No specific vaccine is currently available for enteroinvasive Escherichia coli.
Prophylactic antibiotics are not routinely recommended due to resistance concerns and risk of disrupting normal flora.
Non-pharmacological Prevention
Strict hand hygiene with soap and water to prevent fecal-oral transmission.
Safe drinking water and proper sanitation reduce exposure to contaminated sources.
Proper food handling and cooking to eliminate bacterial contamination.
Avoidance of high-risk foods such as raw vegetables and unpasteurized dairy in endemic areas.
Public health measures including sewage treatment and education on hygiene practices.
Outcome & Complications
Complications
Severe dehydration from fluid loss can lead to hypovolemic shock if untreated.
Hemolytic uremic syndrome is a rare but serious complication associated with invasive E. coli strains.
Toxic megacolon may develop in severe colitis cases.
Bacteremia and systemic infection can occur in immunocompromised patients.
Intestinal perforation is a rare but life-threatening complication.
| Short-term Sequelae | Long-term Sequelae |
|---|---|
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Differential Diagnoses
Dysentery (Enteroinvasive Escherichia coli) versus Shigellosis
Dysentery (Enteroinvasive Escherichia coli) | Shigellosis |
|---|---|
Caused by enteroinvasive Escherichia coli (EIEC), a motile gram-negative rod | Caused by Shigella species, a nonmotile gram-negative rod |
Commonly linked to contaminated food or water in travel or endemic areas | Often associated with fecal-oral transmission in daycare or institutional outbreaks |
Positive stool culture or PCR for enteroinvasive E. coli | Positive stool culture or PCR for Shigella species |
Usually milder dysentery without HUS risk | Typically more severe with higher risk of hemolytic uremic syndrome |
Dysentery (Enteroinvasive Escherichia coli) versus Amebic Dysentery (Entamoeba histolytica)
Dysentery (Enteroinvasive Escherichia coli) | Amebic Dysentery (Entamoeba histolytica) |
|---|---|
Bacterial invasion of colonic mucosa causing ulceration | Protozoan parasite causing flask-shaped colonic ulcers |
Positive stool culture or PCR for enteroinvasive E. coli | Detection of trophozoites or cysts in stool microscopy or antigen testing |
Usually acute onset with self-limited or antibiotic-responsive course | May cause chronic intermittent symptoms and extraintestinal abscesses |
Responds to fluoroquinolones or trimethoprim-sulfamethoxazole | Responds to metronidazole and luminal amebicides |
Dysentery (Enteroinvasive Escherichia coli) versus Campylobacter enteritis
Dysentery (Enteroinvasive Escherichia coli) | Campylobacter enteritis |
|---|---|
Caused by enteroinvasive E. coli, a straight gram-negative rod | Caused by curved gram-negative rods, Campylobacter jejuni |
Associated with contaminated water or food in endemic areas | Associated with undercooked poultry or unpasteurized milk |
Primarily presents with bloody diarrhea and abdominal cramps without prodrome | Often preceded by fever and abdominal cramps, with watery diarrhea progressing to bloody stools |
Positive stool culture or PCR for enteroinvasive E. coli at standard conditions | Positive stool culture on selective media at 42°C microaerophilic conditions |
Dysentery (Enteroinvasive Escherichia coli) versus Salmonella enterocolitis
Dysentery (Enteroinvasive Escherichia coli) | Salmonella enterocolitis |
|---|---|
Caused by enteroinvasive E. coli, a different motile gram-negative rod | Caused by motile gram-negative rods of Salmonella genus |
Linked to contaminated water or food in endemic regions | Linked to contaminated poultry, eggs, or reptiles |
Primarily presents with bloody diarrhea and abdominal cramps | Usually presents with fever, abdominal pain, and diarrhea that may be watery or bloody |
Positive stool culture or PCR for enteroinvasive E. coli | Positive stool culture for Salmonella species |
Dysentery (Enteroinvasive Escherichia coli) versus Clostridioides difficile colitis
Dysentery (Enteroinvasive Escherichia coli) | Clostridioides difficile colitis |
|---|---|
No recent antibiotic exposure typically required | Recent antibiotic use or hospitalization |
Dysentery with bloody diarrhea and mucosal invasion | Profuse watery diarrhea with pseudomembranous colitis |
Positive stool culture or PCR for enteroinvasive E. coli | Positive stool toxin assay for C. difficile toxins A and B |
Responds to fluoroquinolones or trimethoprim-sulfamethoxazole | Responds to oral vancomycin or fidaxomicin |