What are the indications for antibiotic treatment in cases of acute infectious diarrhoea?

Antibiotic treatment is generally not routinely recommended for acute infectious diarrhoea in primary care, as many cases are viral in origin and symptoms are often not shortened by antibiotics ¹. There is also a risk of increasing bacterial resistance with empirical use ¹.

However, antibiotics may be indicated in specific circumstances or for certain confirmed pathogens:

• Amoebiasis (Amoebic Dysentery): Drug treatment, typically metronidazole followed by diloxanide, is usually recommended for all confirmed cases after specialist advice ¹.
• Giardiasis: Metronidazole is prescribed, either 2000 mg once daily for 3 days or 400 mg three times daily for 5 days ¹.
• Shigellosis: Antibiotic treatment is not usually needed for people with mild symptoms ¹. However, if symptoms are severe (high fever, bloody and/or high-output diarrhoea) or the person is immunocompromised, specialist advice should be sought regarding the need for antibiotics ¹.
• Travellers' Diarrhoea: Antibiotics are not recommended for mild symptoms but should be used to treat moderate-to-severe symptoms ¹.
• Acute Diverticulitis: While not always primarily presenting as diarrhoea, antibiotics are considered if the person is systemically unwell, immunosuppressed, or has significant comorbidity ². Oral antibiotics may be offered if systemically unwell but not meeting criteria for complicated acute diverticulitis ². Intravenous antibiotics are offered for suspected complicated acute diverticulitis ². For systemically well individuals with acute diverticulitis, a no-antibiotic prescribing strategy can be considered ².

Antibiotic treatment is generally not needed for non-typhoidal Salmonellosis ¹. There is no effective antibiotic treatment available for Shiga toxin-producing E. coli (STEC) infection ¹.

For non-severe infections, consider taking microbiological samples before deciding on antimicrobial prescribing, provided it is safe to withhold treatment until results are available ⁴.