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Shigellosis

Updated : November 18, 2022





Background

Shigellosis is a type of bacterial diarrhea caused by Shigella species, which are gram-negative bacteria. It is frequent in underdeveloped nations and is caused by contaminated food, inadequate sanitation, or direct person-to-person contact. Shigella can infect people of all ages.

Children, the elderly, and the immunocompromised are all high-risk groups. Shigella species are relatively resistant to stomach acid, and just a few organisms are necessary to produce the sickness.

Epidemiology

Shigellosis is claimed to affect 188 million people each year, with around one million deaths from the disease. In developed countries, the annual incidence is roughly 1.5 million cases. It causes approximately 450,000 cases per year in the United States. S. sonnei is responsible for most cases recorded in the United States. S. flexneri is the serotype most responsible for illness in underdeveloped nations.

It is more prevalent in young children, with the majority of cases documented in children under the age of four and 25 cases/100,000 in children aged four to eleven. Shigella is the most prevalent cause of diarrhea in children under five in South Asia and Sub-Saharan Africa Shigellosis does not have a gender or racial predisposition.

In daycare facilities and residential institutions in the US, shigellosis is common. Additionally, there have been reports of foodborne transmission in the US. Shigellosis outbreaks have also happened in men engaged in intercourse with men.

Anatomy

Pathophysiology

Shigellosis is mainly transmitted through the fecal-oral route in developed nations and the fecal-oral route, food-borne or water-borne, in developing nations. It can, however, be sexually transmitted. Due to the organism’s less sensitivity to stomach acid and downregulation of antibacterial proteins in the host, the number of organisms necessary to produce the sickness is usually between 10 and 200. Shigella penetrates the small intestine and multiplies before entering the large intestine.

Shigella causes cell damage and problems by direct invasion of the colonic mucosa and the generation of enterotoxins. It enters through transcytosis and travels through the basolateral epithelium of the large intestine using M cells, primarily in charge of immunological activation of intestinal lymphoid tissue through antigen recognition. It causes macrophages and cellular death after transcytosis. Inflammatory cytokines like IL-1 and IL-18 are released, causing intestinal inflammation and triggering the innate immune system.

Following cell death and inflammation, Shigella is expelled from the macrophages. It uses the intercellular actin polymerization method to continue invading the immune system and epithelium. As Shigella infiltrates the epithelial cells, it stimulates the cells’ nuclear factor, producing IL-8 that encourages neutrophil recruitment at the site and increases inflammation and epithelial damage. It results in diarrhea by impairing food absorption.

Etiology

Shigella is the cause of the food- or water-borne illness shigellosis. Shigella is a gram-negative, non-spore-forming, facultatively anaerobic rod. It has four serotypes:

Shigella dysenteriae serotype A (12 serotypes), Shigella flexneri serotype B (6 serotypes), Shigella boydii serotype (23 serotypes), Shigella soneii serotype (1 serotype)

While Shigella flexneri and Shigella dysenteriae produce dysentery with bloody diarrhea, Shigella sonnei causes a mild illness that may only result in watery diarrhea.

Genetics

Prognostic Factors

Shigellosis patients have a fair prognosis and recover without complications if they are promptly diagnosed and treated. A delay in treatment, immunocompromised status, prolonged hospitalization, and extremes of age, such as the old and the very young, might result in severe illness and consequences.

Clinical History

Physical Examination

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Medication

Media Gallary

References

https://www.ncbi.nlm.nih.gov/books/NBK482337/

Shigellosis

Updated : November 18, 2022




Shigellosis is a type of bacterial diarrhea caused by Shigella species, which are gram-negative bacteria. It is frequent in underdeveloped nations and is caused by contaminated food, inadequate sanitation, or direct person-to-person contact. Shigella can infect people of all ages.

Children, the elderly, and the immunocompromised are all high-risk groups. Shigella species are relatively resistant to stomach acid, and just a few organisms are necessary to produce the sickness.

Shigellosis is claimed to affect 188 million people each year, with around one million deaths from the disease. In developed countries, the annual incidence is roughly 1.5 million cases. It causes approximately 450,000 cases per year in the United States. S. sonnei is responsible for most cases recorded in the United States. S. flexneri is the serotype most responsible for illness in underdeveloped nations.

It is more prevalent in young children, with the majority of cases documented in children under the age of four and 25 cases/100,000 in children aged four to eleven. Shigella is the most prevalent cause of diarrhea in children under five in South Asia and Sub-Saharan Africa Shigellosis does not have a gender or racial predisposition.

In daycare facilities and residential institutions in the US, shigellosis is common. Additionally, there have been reports of foodborne transmission in the US. Shigellosis outbreaks have also happened in men engaged in intercourse with men.

Shigellosis is mainly transmitted through the fecal-oral route in developed nations and the fecal-oral route, food-borne or water-borne, in developing nations. It can, however, be sexually transmitted. Due to the organism’s less sensitivity to stomach acid and downregulation of antibacterial proteins in the host, the number of organisms necessary to produce the sickness is usually between 10 and 200. Shigella penetrates the small intestine and multiplies before entering the large intestine.

Shigella causes cell damage and problems by direct invasion of the colonic mucosa and the generation of enterotoxins. It enters through transcytosis and travels through the basolateral epithelium of the large intestine using M cells, primarily in charge of immunological activation of intestinal lymphoid tissue through antigen recognition. It causes macrophages and cellular death after transcytosis. Inflammatory cytokines like IL-1 and IL-18 are released, causing intestinal inflammation and triggering the innate immune system.

Following cell death and inflammation, Shigella is expelled from the macrophages. It uses the intercellular actin polymerization method to continue invading the immune system and epithelium. As Shigella infiltrates the epithelial cells, it stimulates the cells’ nuclear factor, producing IL-8 that encourages neutrophil recruitment at the site and increases inflammation and epithelial damage. It results in diarrhea by impairing food absorption.

Shigella is the cause of the food- or water-borne illness shigellosis. Shigella is a gram-negative, non-spore-forming, facultatively anaerobic rod. It has four serotypes:

Shigella dysenteriae serotype A (12 serotypes), Shigella flexneri serotype B (6 serotypes), Shigella boydii serotype (23 serotypes), Shigella soneii serotype (1 serotype)

While Shigella flexneri and Shigella dysenteriae produce dysentery with bloody diarrhea, Shigella sonnei causes a mild illness that may only result in watery diarrhea.

Shigellosis patients have a fair prognosis and recover without complications if they are promptly diagnosed and treated. A delay in treatment, immunocompromised status, prolonged hospitalization, and extremes of age, such as the old and the very young, might result in severe illness and consequences.

https://www.ncbi.nlm.nih.gov/books/NBK482337/