What is the treatment for salmonella?

Treatment of Salmonella Infections

When to Treat vs. Observe

Most immunocompetent adults and children over 1 year with uncomplicated gastroenteritis do NOT require antibiotic treatment, as the infection is self-limiting and antibiotics may prolong bacterial shedding. 1

However, treatment is mandatory in the following populations:

• All infants <3 months of age due to high risk of bacteremia and extraintestinal spread 1, 2
• All immunocompromised patients (HIV, transplant recipients, chronic immunosuppression) due to high bacteremia risk 1, 2
• Patients with documented bacteremia or septicemia 1, 3
• Pregnant women due to risk of placental/amniotic fluid infection and pregnancy loss 4, 1
• Patients with severe disease requiring hospitalization 1

First-Line Treatment for Adults

Ciprofloxacin 500 mg orally twice daily is the first-line treatment for Salmonella infections in immunocompetent adults. 3, 2, 1, 5

For immunocompromised patients or severe infections, initiate combination therapy with:

• Ceftriaxone 2 g IV once daily PLUS ciprofloxacin 500 mg orally twice daily until susceptibility results are available 3, 2, 1

Alternative Antibiotics (Based on Susceptibility)

• Trimethoprim-sulfamethoxazole (TMP-SMX): Effective alternative if organism is susceptible 3, 2, 1
• Ceftriaxone 2 g IV once daily: For severe infections or cephalosporin-susceptible strains 3, 2, 1
• Cefotaxime: Alternative third-generation cephalosporin 4, 2
• Amoxicillin: Only if susceptibility is confirmed 2, 1
• Azithromycin: Emerging as preferred option due to less resistance development and better safety profile 6

Special Population Considerations

Children

Fluoroquinolones should be avoided in children under 18 years and used only if no alternatives exist. 4, 2, 1

Preferred pediatric options:

• TMP-SMX, ceftriaxone, cefotaxime, or ampicillin 4, 2
• Chloramphenicol (if susceptible) 4
• Antiperistaltic drugs are contraindicated in children 4

Pregnant Women

Fluoroquinolones must be avoided during pregnancy. 4, 2

Safe alternatives include:

• Ampicillin, ceftriaxone, cefotaxime, or TMP-SMX 4, 2, 1

HIV/Immunocompromised Patients

All HIV-infected patients with Salmonella infection require treatment regardless of severity. 2, 1

• Initial therapy: Ceftriaxone 2 g IV once daily PLUS ciprofloxacin 500 mg orally twice daily until susceptibilities available 3, 1
• Long-term suppressive therapy with ciprofloxacin 500 mg twice daily for at least 2 months may be needed to prevent recurrence 3, 1

Treatment Duration

The duration depends on clinical presentation and immune status:

• Uncomplicated gastroenteritis (if treating): 7-14 days 2, 1
• Bacteremia in immunocompetent patients: Minimum 14 days 3, 2, 1
• Bacteremia in immunocompromised patients: 14 days or longer if relapsing 1
• Advanced HIV disease (CD4+ <200 cells/μL): 2-6 weeks 3, 2, 1
• Recurrent septicemia: Consider 6 months or more as secondary prophylaxis 3, 1

Critical Management Pearls

Expect persistent fever for 5-7 days despite appropriate antibiotic therapy—this does NOT indicate treatment failure. 3, 1

Treatment failure is defined as:

• Lack of clinical improvement AND persistent positive blood cultures after completing therapy 3, 1

When treatment failure occurs, evaluate for:

• Malabsorption of oral antibiotics 3, 1
• Undrained abscess or sequestered infection focus 3, 1
• Adverse drug reactions interfering with antimicrobial activity 1
• Co-infection with other organisms (e.g., C. difficile) 1

Prevention of Recurrence

For HIV-infected patients with prior Salmonella septicemia:

• Long-term suppressive therapy with ciprofloxacin (preferred fluoroquinolone) is required 4, 3
• Duration: At least 2 months, potentially 6+ months for recurrent disease 3, 1

Screen household contacts for asymptomatic carriage to prevent reinfection, especially in immunocompromised patients 4, 3

Emerging Resistance Concerns

Increasing fluoroquinolone resistance makes therapy selection problematic in some regions. 3, 2

• Always obtain susceptibility testing to guide final antibiotic selection 3, 2, 1
• Extended-spectrum beta-lactamase (ESBL) production and multidrug resistance are increasing 7, 8
• Azithromycin and ceftriaxone show superior efficacy based on hospital length of stay and fever resolution rates 6

Medications to Avoid

Antiperistaltic agents (diphenoxylate, loperamide) should be discontinued if:

• Symptoms persist beyond 48 hours 4
• High fever is present 4
• Blood is present in stool 4