Salmonella Gastroenteritis Treatment
Primary Recommendation
For otherwise healthy adults and children over 3 months with uncomplicated Salmonella gastroenteritis, antibiotics should NOT be given—focus exclusively on supportive care with oral rehydration. 1, 2, 3
Supportive Care (All Patients)
- Fluid and electrolyte replacement is the cornerstone of therapy for all patients with Salmonella gastroenteritis. 2, 4
- Oral rehydration solution (ORS) is preferred for mild to moderate dehydration; administer until clinical dehydration is corrected, then continue to replace ongoing stool losses. 2, 3
- Intravenous fluids are necessary only for severe dehydration or inability to tolerate oral intake. 2, 4
- Resume age-appropriate diet immediately after rehydration is complete—do not delay feeding. 3
- Continue breastfeeding throughout illness if applicable. 3
Medications to Avoid
- Never give antimotility agents (loperamide) to children under 18 years—this can precipitate toxic megacolon and worsen invasive disease. 2, 3, 4
- Avoid antimotility agents in any patient with high fever or bloody stools. 1, 4
- Antiemetics (ondansetron) may be considered only in children over 4 years if vomiting interferes with oral rehydration. 2, 3
High-Risk Populations Requiring Antibiotic Treatment
The following groups require antibiotic therapy due to risk of bacteremia and extraintestinal spread:
1. Infants Under 3 Months
- All infants under 3 months require antibiotic treatment due to bacteremia rates of 45% in neonates and 11% in older infants, with risk of meningitis and osteomyelitis. 3, 4, 5
- First-line options: TMP-SMX, ampicillin, cefotaxime, ceftriaxone, or chloramphenicol based on local susceptibility. 1, 3
- Avoid fluoroquinolones in children under 18 years due to cartilage toxicity risk, except in life-threatening situations with no alternatives. 3, 4
- Treatment duration: 7-14 days for uncomplicated cases; 14+ days for bacteremia. 3
2. HIV-Infected Patients
- All HIV-infected persons with Salmonella gastroenteritis must receive antibiotic treatment due to high risk of bacteremia and extraintestinal spread. 1, 2, 4
- First-line for adults: Ciprofloxacin 750 mg orally twice daily. 1, 2
- For severe disease or immunocompromised patients, start empiric combination therapy with ceftriaxone 2g IV once daily plus ciprofloxacin 500 mg orally twice daily until susceptibilities available. 2, 4
- Treatment duration varies by CD4 count: 7-14 days for CD4 >200 cells/μL; 2-6 weeks for CD4 <200 cells/μL. 1, 2, 4
- HIV patients with prior Salmonella septicemia require long-term suppressive therapy to prevent recurrence. 1, 2, 4
- Screen household contacts for asymptomatic carriage to prevent reinfection. 2, 3, 4
3. Pregnant Women
- Pregnant women with Salmonella gastroenteritis should receive treatment due to risk of placental/amniotic fluid infection leading to pregnancy loss. 1, 2, 4
- Treatment options: Ampicillin, cefotaxime, ceftriaxone, or TMP-SMX. 1, 2
- Avoid fluoroquinolones during pregnancy. 1
4. Other Immunocompromised Patients
- Transplant recipients, chronic immunosuppression, malignancy patients require treatment due to risk of disseminated infection. 2, 4
- Use same regimens as HIV-infected patients above. 2, 4
5. Bacteremia or Invasive Disease
- All patients with documented bloodstream infection or severe invasive disease requiring hospitalization need antibiotic therapy. 2, 4
- Immunocompetent adults with bacteremia: Ciprofloxacin 500-750 mg orally twice daily for 7-14 days. 2, 4
- Immunocompromised patients: Ceftriaxone 2g IV once daily plus ciprofloxacin until susceptibilities available, then de-escalate to monotherapy. 2
Why Antibiotics Are NOT Recommended for Uncomplicated Cases
- Antibiotics do not shorten illness duration in otherwise healthy patients—no significant difference in length of diarrhea or fever versus placebo. 1, 6
- Antibiotics increase adverse effects (odds ratio 1.67) including drug reactions. 6
- Antibiotics prolong fecal shedding of Salmonella beyond 3 weeks, increasing transmission risk. 1, 6
- Antibiotics increase relapse rates compared to supportive care alone. 1, 6
- The modest treatment benefit in severe infections does not outweigh risks in most cases. 1
Antibiotic Selection When Treatment Is Indicated
Adults
- First-line: Ciprofloxacin 500-750 mg orally twice daily for 7-14 days. 2, 4
- Alternative options based on susceptibility: TMP-SMX, ceftriaxone 2g IV once daily, cefotaxime, or ampicillin. 1, 2, 4
- Note: Fluoroquinolone resistance is increasing, particularly in Southeast and South Asia—avoid empiric use for travel-related infections from these regions. 1
Children
- First-line: TMP-SMX, ceftriaxone, cefotaxime, or ampicillin based on susceptibility. 1, 3
- Avoid fluoroquinolones in children under 18 years except in life-threatening situations. 3, 4
- Treatment duration: 7-14 days for uncomplicated cases; 14+ days for bacteremia. 3
Critical Pitfalls to Avoid
- Do not treat Shiga toxin-producing E. coli (STEC) with antibiotics—this increases risk of hemolytic uremic syndrome. Consider STEC in any patient with bloody diarrhea, especially when fever is absent. 1, 4
- Do not give antimotility agents to children or patients with high fever/bloody stools—risk of toxic megacolon. 2, 3, 4
- Do not undertreat duration in immunocompromised patients—inadequate treatment length leads to relapse. 2
- Do not use ceftriaxone monotherapy empirically for bacteremia in immunocompromised patients—combination therapy prevents treatment failure. 2
Infection Control and Prevention
- Hand hygiene with soap and water (preferred over alcohol-based sanitizers) after toilet use, diaper changes, before food preparation/eating, and after animal contact. 3, 4
- Ill patients should avoid swimming, water activities, and close contact with others until diarrhea resolves. 2, 3, 4
- Proper cooking and storage of foods containing meats and eggs to prevent cross-contamination. 2