Approach

In otherwise healthy adults, most cases of shigellosis are mild and self-limiting.[6]

In more severe cases, rehydration therapy plays an important role, together with nutritional support and antibiotics.[16][17][24][32] Antibiotic therapy improves symptoms, treats infection, and limits the spread of disease.[16]

Rehydration therapy

Although shigellosis usually produces a low-volume diarrhoea, patients occasionally become volume depleted. This is more common in children and if vomiting occurs.

In Shigella dysentery, oral rehydration therapy (using approved oral rehydration solution [ORS]) is indicated in mild to moderate volume depletion. Following rehydration, maintenance therapy with ORS to ensure hydration status is recommended.[16]​​[24]

Intravenous rehydration therapy may be initially required for patients with vomiting or severe volume depletion. Once rehydrated, maintenance therapy with ORS is recommended. If rehydrated patients are unable to drink, maintenance therapy with ORS may be provided nasogastrically (when intravenous fluids are no longer required and any vomiting resolves).

Oral rehydration therapy using an approved ORS is safer than use of other beverages, which may be too concentrated and contain inappropriate carbohydrate and electrolyte concentrations. Home-made preparations may be equally problematic because errors may occur. The World Health Organization (WHO) recommends low-osmolarity ORS formula for diarrhoea in all age groups.[33]

Early nutritional support

This has been found to improve outcomes, especially in the context of malnutrition. Continued feeding promotes recovery. Frequent small meals with familiar foods, rich in energy and protein, should be provided. Breastfed infants and children should continue to be breastfed as often, and for as long, as they want.[16]

The addition of green bananas to meals has been shown to reduce the duration of symptoms of shigellosis in children >6 months of age (probably because the poorly digestible starches in green bananas increase short-chain fatty acid production in the colon).[34] In low- and middle-income countries, a 10- to 14-day course of zinc supplementation is recommended by the WHO in children <6 years of age with acute diarrhoea.[16] [ Cochrane Clinical Answers logo ] ​ Vitamin A is also recommended.[33]

Health education and infection control measures

Information regarding personal hygiene, food, and drinking water should be provided to all patients. Outpatients should also be clearly instructed how to disinfect clothes, personal items, and their immediate environment.[16] Sexual activities should be avoided while symptomatic and for up to 7 days after symptoms have stopped. Organisms in stool may continue to shed for up to 6 weeks, so faecal-oral contact during sex should be avoided for this period of time.[24][35]​​

Antibiotics

A Cochrane review found that antibiotics reduce the duration of diarrhoea in patients with Shigella dysentery.[36] However, routine prescription of antibiotic therapy for suspected or confirmed Shigella infection is not recommended; antibiotic therapy is reserved for where it is clinically indicated or when public health officials advise treatment in an outbreak setting or to reduce the likelihood of transmission in certain settings or situations.[37]​​

Clinical indications for empirical antibiotics include all cases of fever with bloody diarrhoea, bacillary dysentery, and abdominal cramping.[24]​ Antibiotics are also recommended for infants aged <3 months with suspicion of Shigella infection and people with body temperatures ≥38.5°C and/or signs of sepsis who have recently travelled internationally.[24] Antibiotics may be considered in people who are immunocompromised and have severe illness and bloody diarrhoea.[24]

First-line options are azithromycin, ciprofloxacin, or ceftriaxone.​[1][24]​​ The choice of drug is dependent on local sensitivities. If available, antimicrobial susceptibility testing should be carried out before treating with antibiotics.[1] The rapid emergence of fluoroquinolone resistance is a concern, particularly in India and China.[16][38][39][40] Patients with a history of travel to Asia are thus at increased risk of fluoroquinolone-resistant infection.[41]​ If susceptibility is detected, trimethoprim/sulfamethoxazole or ampicillin are alternative options.[24][25]​​​ ​

Once infection has been confirmed, antibiotics should be promptly tailored to sensitivities to prevent resistance. If the correct antibiotic has been used initially but the patient is refractory to treatment, further cultures should be sent to exclude another pathogen, or an alternative diagnosis should be considered.

Extensively drug-resistant Shigella infection (XDR) is an increasing concern; in 2022 around 5% of Shigella infections reported in the US were caused by XDR strains.[37]​ The US Centers for Disease Control and Prevention do not have current recommendations for treating XDR Shigella. An infectious disease specialist should be consulted.

Following an XDR Shigella outbreak in the UK, clinicians are advised to test stool for bacterial culture, PCR (where available) and antibiotic susceptibility, in men who have sex with men, who have diarrhoeal illness lasting over 7 days, bloody diarrhoea, or illness requiring hospitalisation. Treatment should be based on sensitivities.[20]

Adjunctive treatments

Antispasmodic agents are generally not recommended.[42] Antidiarrhoeal medications should not be used, because there is anecdotal concern that they may promote toxic dilation. Symptomatic treatment should be given in case of fever and/or pain. Zinc supplementation is recommended in low- and middle-income countries in children under 6 years of age, but there is probably no benefit in children under 6 months old.[43]

Ongoing considerations

Chronic Shigella carriage is uncommon, and therefore treatment is not usually a consideration. If chronic carriage is suspected, discussion with an infectious diseases expert is recommended.

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