Shigella infection

Shigella infection is easily spread by faecal-oral contact or by contaminated water or food. It usually presents as a mild, self-limiting diarrhoeal illness.

Shigella dysenteriae is more common in low- and middle-income countries and causes a more severe illness with dysentery. S dysenteriae type 1 is a cause of haemolytic uraemic syndrome owing to its production of Shiga toxin.

Treatment is usually supportive in mild cases. Antibiotics may be useful to shorten the course of the illness and reduce shedding of the organism in stool.

Empirical antibiotics are recommended for children and adults with severe disease, for older adults, for malnourished or chronically ill patients, and to reduce spread (e.g., in institutions).

Prevention is paramount, including basic hygiene measures such as hand-washing, access to clean water, and cooking, especially in institutions and camps during natural disasters. Immunisations are in developmental stages.

Shigellosis is an important cause of diarrhoeal disease worldwide, most commonly affecting children <5 years old.[1]Center for Disease Control and Prevention. CDC Yellow Book 2024: health information for international travel. Section 5: travel-associated infections & diseases - shigellosis. Jun 2023 [internet publication]. https://wwwnc.cdc.gov/travel/yellowbook/2024/infections-diseases/shigellosis [2]Khalil IA, Troeger C, Blacker BF, et al. Morbidity and mortality due to shigella and enterotoxigenic Escherichia coli diarrhoea: the Global Burden of Disease Study 1990-2016. Lancet Infect Dis. 2018 Nov;18(11):1229-40. https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(18)30475-4/fulltext http://www.ncbi.nlm.nih.gov/pubmed/30266330?tool=bestpractice.com ​​​[3]Centers for Disease Control and Prevention (CDC). National Shigella surveillance: Shigella Annual Report, 2016. 21 May 2018 [internet publication]. http://www.cdc.gov/nationalsurveillance/shigella-surveillance.html ​​​​ ​Shigella is a genus of the Enterobacteriaceae family, consisting of four species of aerobic, non-motile, non-lactose-fermenting gram-negative rods: S sonnei, S flexneri, S boydii, and S dysenteriae.

Shigellosis may spread from person to person (by faecal-oral contact), and via contaminated water and food. Outbreaks occur in institutions and in overcrowded areas where sanitation is poor. Although not equivalent, the term 'bloody diarrhoea' is sometimes used interchangeably by clinical practitioners.