Indications for antibiotic therapy for Salmonella enteritis

In otherwise healthy patients without risk factors for complications, nontyphoidal Salmonella enteritis is usually self-limiting. Antibiotic treatment is not indicated in these patients because it does not shorten duration of illness, is associated with a higher rate of adverse events, and can prolong excretion of pathogens. Rehydration is the mainstay of therapy.

Antibiotics are not indicated for asymptomatic short-term nontyphoidal Salmonella carriage.

Antibiotic therapy for nontyphoidal Salmonella enteritis is usually restricted to patients with severe diarrhoea, and patients with the following risk factors for complications:

• neonates and children younger than 3 months
  • refer for assessment at a hospital with adequate expertise
  • before administering antibiotics, collect blood samples for culture and, when relevant, cerebrospinal fluid samples for microscopy and culture to exclude systemic infection and meningitis
• patients older than 70 years, particularly those with frailtyWhite, 2019
• patients with invasive disease, sepsis or bacteraemia
• patients with prosthetic vascular grafts or haemoglobinopathies
• patients with immune compromise, including patients with HIV infectionNIH Office of AIDS Research Advisory Council (OARAC), 2023.

Patients with undiagnosed HIV infection may present initially with recurrent nontyphoidal Salmonella enteritis or, in adults, complications of nontyphoidal Salmonella (eg invasive disease, bacteraemia, osteomyelitis and septic arthritis). These are indicator conditions for HIV testing¹; offer HIV testing, regardless of whether the patient has behavioural or epidemiological risk factors for HIV infection.

Antibiotic resistance among nontyphoidal Salmonella acquired in Australia remains uncommonAustralian Commission on Safety and Quality in Health Care (ACSQHC), 2023Williamson, 2018. In patients who have acquired the infection overseas, antibiotic resistance is common and varies by geographical regionFord, 2023Williamson, 2018. In returned travellers with nontyphoidal Salmonella infection complicated by sepsis or septic shock, broader initial therapy may be required – seek expert advice from an infectious diseases physician.

Unlike most patients with nontyphoidal Salmonella enteritis, patients with typhoid or paratyphoid infection require antibiotic treatment; for considerations and regimens, see Approach to managing typhoid and paratyphoid fevers.