Dysentery or Shigellosis

Shigellosis (Shigella infection, bacillary dysentery, Marlow syndrome, шигеллез, Бактериальная дизентерия, داء الشيغيلات) is an intestinal infectious disease caused by bacterium shigella (Shigella dysenteria, S. flexneri, Sonnei, S. boydii), it is characterized by a bloody diarrhea, fever, and stomach cramps starting a day or two after contamination, in most cases Shigellosis usually resolves within 5 to 7 days.

Shigellosis in the United States:

Shigellosis is the leading cause of bloody diarrhea in the United States

Epidemiological Significance:

• Prevalence: Shigellosis stands as a prominent cause of bloody diarrhea within the United States.
• Incidence: Annually, approximately 500,000 cases of shigellosis are diagnosed, reflecting its substantial impact on public health.

Clinical Impact:

• Bloody Diarrhea: Shigellosis manifests prominently through symptoms such as bloody diarrhea, a characteristic feature of the infection.
• Gastrointestinal Distress: The infection induces a range of gastrointestinal symptoms, contributing to its clinical significance.

Public Health Implications:

• Leading Cause: Shigellosis emerges as a leading contributor to infectious gastroenteritis, necessitating vigilant public health measures.
• Diagnostic Challenges: The distinct clinical presentation of bloody diarrhea underscores the importance of accurate diagnostic approaches to identify and manage cases effectively.

Classification of Dysentery:

A. Acute Dysentery:

1. Colitis Dysentery:

• Description: Characterized by inflammatory changes in the colon, leading to symptoms such as bloody stools, abdominal pain, and tenesmus.
• Clinical Features: Granulomatous enteritis may be present, contributing to the distinctive features of colitis dysentery.

2. Gastroenterocolitis:

• Description: Encompasses inflammation of both the stomach and colon, resulting in a broader range of gastrointestinal symptoms.
• Clinical Features: Presents with symptoms such as abdominal cramping, diarrhea, and, in severe cases, dehydration.

B. Chronic Dysentery:

1. Recidive Dysentery (Recidive, Continuous):

• Description: Characterized by recurrent episodes of dysentery, with intermittent periods of symptom remission.
• Clinical Features: Individuals with recidive dysentery may experience repeated flare-ups, each resembling acute dysentery.

2. Subclinical Dysentery (Subclinical Course):

• Description: Exhibits a less overt presentation of dysentery, with milder or subclinical symptoms.
• Clinical Features: While symptoms may be less pronounced, individuals with subclinical dysentery still harbor the causative pathogens and may act as potential sources of infection.

Causative Pathogens of Acute Dysentery:

Pathogens: Shigella dysenteria, S. flexneri, Sonnei, S. boydii.

1. Shigella dysenteriae:

Characteristics:

• Overview: Shigella dysenteriae is a primary causative agent of acute dysentery.
• Clinical Impact: Known for its association with severe forms of dysentery, leading to substantial gastrointestinal and systemic symptoms.
• Serotype: Classically classified into serotypes, each exhibiting specific O-antigens contributing to its pathogenicity.

2. Shigella flexneri:

Characteristics:

• Overview: Shigella flexneri is a significant contributor to the incidence of dysentery worldwide.
• Distribution: Prevalent in areas with poor sanitation and hygiene practices.
• Clinical Impact: Known for causing various degrees of dysentery, ranging from mild to severe.

3. Shigella Sonnei:

Characteristics:

• Overview: Shigella Sonnei is a common cause of dysentery, especially in industrialized regions.
• Clinical Impact: Frequently associated with milder forms of dysentery, with symptoms typically less severe compared to other Shigella species.

4. Shigella boydii:

Characteristics:

• Overview: Shigella boydii is identified as a causative agent of dysentery.
• Geographical Distribution: Often found in regions with specific environmental conditions, contributing to its prevalence.
• Clinical Impact: Known for inducing dysentery symptoms with variations in severity.

Epidemiology of Acute Dysentery:

1. Source of Infection:

Potential Carriers:

• Source of Infection: Primarily traced back to individuals actively manifesting the disease (patients) or those harboring the pathogen without showing symptoms (bacillicarriers).

Bacillicarrier Definition:

• Definition: Individuals carrying the Shigella bacteria asymptomatically, yet capable of transmitting the pathogen to others.

Transmission Dynamics:

• Dynamic Transmission: The transmission of Shigella can occur from both symptomatic patients and bacillicarriers, underscoring the potential for silent carriers to contribute to the spread of the infection.

2. Mechanism of Transmission:

Route of Transmission:

• Fecal-Oral Route: The primary mode of transmission involves the fecal-oral route, emphasizing the contamination of food, water, and household contacts.

Common Transmission Vectors:

• Food Contamination: Shigella can be transmitted through the consumption of contaminated food, where the pathogen is introduced through poor hygiene practices during food preparation or handling.
• Water Contamination: Contaminated water sources, often due to inadequate sanitation measures, serve as a significant vector for the transmission of Shigella.
• Household Contacts: Close contact with infected individuals or contaminated surfaces within the household setting contributes to the spread of the pathogen.

Clinical picture

Onset and Incubation Period of Acute Dysentery:

1. Incubation Period:

Duration:

• Incubation Period: Ranges from 1 to 7 days, representing the interval between the exposure to Shigella and the onset of noticeable symptoms.

The incubation period signifies the time elapsed between exposure to the Shigella pathogen and the emergence of clinically evident symptoms. This window can vary, with individuals experiencing the first signs of acute dysentery within a span of 1 to 7 days after contact with the infectious agent.

2. Acute Onset:

Nature of Onset:

• Onset: Abrupt and acute, characterized by the sudden appearance of symptoms associated with dysentery.

The onset of acute dysentery is marked by a swift and sudden appearance of clinical manifestations. This rapid onset underscores the virulence and aggressiveness of the Shigella infection, leading to the prompt development of symptoms such as gastrointestinal distress, intoxication syndrome, and fever.

Clinical Syndromes in Acute Dysentery:

1. Intoxication Syndrome:

Clinical Features:

• Temperature Elevation: A notable rise in body temperature, reaching 38 – 39°C, indicative of a febrile response to the Shigella infection.
• Systemic Weakness: Generalized weakness affecting overall physical strength and stamina.
• Cephalalgia (Headache): Persistent headache, often associated with the febrile state and systemic response to the infection.
• Gastrointestinal Distress: Nausea and vomiting contribute to the overall discomfort experienced by the patient.
• Hypotension: A decrease in blood pressure, reflecting the impact of the infection on the circulatory system. Notably, the intensity of the intoxication syndrome is more pronounced in cases of colitis dysentery.

2. Gastrointestinal Syndrome:

Stool Characteristics:

• Frequency: Frequent bowel movements, ranging from 5 to 20 times a day. In severe cases, the frequency may become so pronounced that precise counting becomes challenging.

The gastrointestinal syndrome is characterized by a significant increase in bowel activity, leading to frequent and, in severe cases, profuse stool output. This clinical manifestation underscores the impact of Shigella infection on the intestinal tract, contributing to the overall symptomatology of acute dysentery.

Colitis Variant of Acute Dysentery:

The colitis variant of acute dysentery presents distinctive clinical features, including:

1. Stool Characteristics:

The Colitis variant of an acute dysentery is characterized by scanty stools, often containing mucus and streaks of blood. In some instances, rectal spittle or mucus streaked with blood may be observed without the presence of formed stool. Notably, in cases of catarrhal proctosigmoiditis, blood is typically absent in the stool.

2. Pathological Impurities:

The presence of granulomatous enteritis and microscopic intestinal lesions relevant to Porcine Circovirus Type 2 (PCV2) is often accompanied by the pathological impurities in the stool, including mucus and blood streaks.

3. Abdominal Pain Localization:

Abdominal pain is localized along the projection of the large intestine, with a higher frequency of occurrence in the area of spasm of the sigmoid colon. The pain is of a spastic character.

4. Tenesmus and Anorectal Symptoms:

Dysenteric colitis is marked by tenesmus, false urges to defecate, and painful contractions of the anus following defecation. These symptoms contribute to the overall discomfort experienced by affected individuals.

5. Dehydration-Related Syndrome:

The syndrome may develop in cases of dehydration associated with gastroenterocolitis and gastroenteric forms. Manifestations are detailed in the section on “Salmonellosis“. However, severe dehydration is not a characteristic feature of this variant.

Complications in Severe Shigellosis, Specifically Flexner 2a:

Complications primarily manifest in severe cases of shigellosis, particularly those caused by the Flexner 2a strain. These complications may include:

1. Infectious-Toxic Shock:

A severe and potentially life-threatening condition characterized by a systemic inflammatory response to the toxins produced by the Flexner 2a strain of Shigella. This can lead to multi-organ dysfunction and circulatory collapse.

2. Gastrointestinal Bleeding:

The presence of blood in the gastrointestinal tract, often stemming from ulceration and damage to the intestinal mucosa caused by the aggressive infection. Gastrointestinal bleeding can result in anemia and further complications.

3. Intestinal Obstruction:

A blockage or constriction of the intestines, typically due to severe inflammation, tissue damage, or the formation of adhesions as a result of the Shigella infection. Intestinal obstruction can lead to abdominal pain, vomiting, and impaired bowel function.

Understanding these complications is crucial in the clinical management of severe shigellosis, as they require prompt medical intervention and tailored treatment strategies. In cases of infectious-toxic shock, gastrointestinal bleeding, or intestinal obstruction, immediate medical attention is essential to mitigate the risks associated with these potentially life-threatening complications.

Altered Intestinal Microbiota in Shigellosis:

The predominant outcome observed in the majority of patients with shigellosis is the development of dysbacteriosis, signifying significant disruptions in the microbial ecology of the intestines.

The absolute majority of patients develop dysbacteriosis.

Dysbacteriosis:

• An imbalance or disturbance in the normal composition and function of the intestinal microbiota. Shigella infection contributes to dysbacteriosis by disrupting the delicate equilibrium of beneficial and harmful microorganisms within the gastrointestinal tract.

Consequences of Dysbacteriosis:

1. Microbial Imbalance:

Shigella’s invasive nature disrupts the usual balance between beneficial (commensal) and potentially harmful microorganisms in the gut. This imbalance can affect the normal functioning of the digestive system.

 2. Impaired Nutrient Absorption:

Dysbacteriosis may compromise the absorption of essential nutrients in the intestines, potentially leading to nutritional deficiencies in affected individuals.

3. Gastrointestinal Distress:

The altered microbiota can contribute to gastrointestinal distress, including symptoms such as abdominal discomfort, bloating, and irregular bowel movements.

4. Immune System Modulation:

Dysbacteriosis can influence the immune system’s response, impacting the body’s ability to mount an effective defense against infections and maintain overall immune homeostasis.

Understanding the implications of dysbacteriosis in the context of shigellosis is pivotal for healthcare professionals in devising comprehensive management strategies aimed at restoring intestinal health and fostering the recovery of affected individuals.

Diagnosing Shigellosis: Understanding the Tests

1. Laboratory Diagnosis:

Bacteriological Testing (Stool Culture Test):

• What it involves: Culturing and isolating Shigella bacteria from a stool sample.
• How it works: The laboratory examines a sample of your stool to identify the presence of Shigella bacteria

Serological Testing:

• What it involves: Assessing antibodies in your blood against Shigella O-antigens.
• How it works: A blood test measures the levels of antibodies. Increasing titers indicate a potential Shigella infection.

Additional methods include ELISA and aggregate hemagglutination techniques (РАГА).

In the United States, European Union, China, and Israel, several serological tests may be employed to detect antibodies against Shigella O-antigens, depending on the healthcare facility and available testing methods. The choice of a specific serological test can vary, and some common methods include:

1. Enzyme-Linked Immunosorbent Assay (ELISA):

ELISA is widely used globally and can be adapted to detect antibodies against Shigella O-antigens.

2. Agglutination Tests:

Tests like the Widal test may be used, involving the agglutination of bacteria in the presence of specific antibodies.

3. Western Blot:

Western blotting techniques can provide detailed information about the presence of specific antibodies.

4. Multiplex Bead Assays:

These advanced assays use microspheres to simultaneously test for multiple antibodies, offering high sensitivity.

It’s essential to note that the choice of a serological test may depend on factors such as the availability of resources, laboratory equipment, and the preferences of healthcare professionals or institutions. The specific equivalent to the RPGA test used in Russia may vary across different regions and healthcare settings. Healthcare providers in each country typically follow guidelines established by relevant health authorities to determine the most appropriate serological test for detecting antibodies against Shigella O-antigens.

For a relatively easy and cost-friendly alternative to the RPGA test, Enzyme-Linked Immunosorbent Assay (ELISA) is often a practical choice. ELISA is widely utilized for serological testing and offers several advantages:

• Cost-Effectiveness: ELISA is generally cost-friendly compared to some other serological tests. The reagents and materials required are often readily available and affordable.
• Ease of Use: ELISA procedures are relatively straightforward, and many laboratories are equipped to perform this test. It is considered user-friendly and doesn’t require specialized skills.
• High Sensitivity and Specificity: ELISA is known for its sensitivity and specificity, making it a reliable option for detecting antibodies against Shigella O-antigens.
• Quantitative Results: ELISA can provide quantitative results, offering information about the antibody titers present in the patient’s blood.

Given its affordability, simplicity, and reliability, ELISA is commonly employed as an alternative to more complex and costly serological tests. However, the specific choice of test can depend on local laboratory capabilities, available resources, and regional preferences in healthcare practices.

2. Rectoromanoscopic Study:

• What it involves: A detailed examination of the rectum and sigmoid colon.
• How it works: A medical professional uses a rectoromanoscope to visually inspect the rectum and sigmoid colon. Findings may include a catarrhal picture (inflammation), erosive changes, ulceration, or fibrinous proctosigmoiditis of the sphincter.

Treatment

Etiotropic Treatment: For the infection itself, take furazolidone at a dose of 0.1g three to four times daily, half an hour after meals, for five days. If necessary, consider alternatives such as Ercefuryl or Intetrix.

Severe Shigellosis: In cases of severe infection, especially with Flexner 2a, initiate treatment with fluoroquinolone drugs like Ciprofloxacin. Administer 500 mg twice daily for 3-4 days.

Pathogenetic and Immunomodulatory Treatment:

Addressing Colon Changes: Anti-inflammatory drugs or Disease-Modifying Antirheumatic Drugs (DMARDs), such as Sulfasalazine (SALAZOPYRIN®), play a pivotal role in managing cases where destructive changes in the mucosa and submucosa of the colon are confirmed.

Sulfasalazine (SALAZOPYRIN®):

• Dosage: Administer orally at a dose of 3-4 g/day, divided into three times a day after meals.
• Brand Alternatives: If needed, consider alternative Sulfasalazine brands, including Azulfidine® or Azulfidine EN.
• Alternative Dosage: Azulfidine® or Azulfidine EN can be administered at a dose of 1 to 2 g four times daily.

Pediatric Dosage:

• For children, the recommended dosage is 40 to 60 mg/kg of body weight daily, distributed in three to six divided doses.

Detoxification therapy:

Implement detoxification therapy to assist the body in eliminating harmful substances.

Symptomatic Relief: Alleviate symptoms through the following:

Spasmolytics: Take medications like papaverine or no-spa to ease abdominal pain and cramps.

Enzyme Preparations: Aid digestion with Mezim or Festal.

Astringents: Control diarrhea with medications like Imodium, Cholestyramine powder, or bismuth.

Microclisma: Administer an enema with herbal decoctions such as chamomile, oak bark, sea buckthorn oil, and rosehip.

Probiotics: After analyzing fecal flora, introduce probiotics like Bifidumbacterin or Laktobakterin to restore and maintain a balanced gut microbiome. This helps in fostering a healthy environment for beneficial bacteria.

Verified by: Dr.Diab (February 3, 2024)

Citation: Dr.Diab. (February 3, 2024). Shigellosis clinical picture and treatment. Medcoi Journal of Medicine, 16(2). urn:medcoi:article15973.