What is the recommended treatment for an otherwise healthy adult with a suspected food salmonella infection?

Treatment of Food Salmonella Infection in Otherwise Healthy Adults

For an otherwise healthy adult with suspected food salmonella infection, supportive care with oral rehydration is the only treatment needed—antibiotics should NOT be given. 1

Why No Antibiotics for Healthy Adults

Antibiotics provide no clinical benefit in immunocompetent adults with uncomplicated Salmonella gastroenteritis. The condition is self-limited, and antibiotic treatment does not shorten the duration of illness, diarrhea, or fever 2. In fact, antibiotics cause more harm than good in this population:

• Antibiotics prolong the carrier state, with more positive stool cultures after three weeks of treatment 2
• Relapses occur more frequently in patients who receive antibiotics 2
• Adverse drug reactions are significantly more common in antibiotic-treated groups (odds ratio 1.67) 2

The American College of Physicians explicitly recommends providing only oral rehydration and supportive care without antibiotics for immunocompetent adults with uncomplicated Salmonella gastroenteritis 1.

Supportive Care Protocol

Oral rehydration is the cornerstone of therapy:

• Use reduced osmolarity oral rehydration solution (ORS) until clinical dehydration is corrected 1
• Continue ORS to replace ongoing stool losses until diarrhea resolves 1
• Resume normal age-appropriate diet immediately after rehydration—do not delay feeding 1

Avoid antimotility agents (such as loperamide), as these can worsen outcomes and precipitate complications 3.

High-Risk Populations Requiring Antibiotics

While healthy adults do not need antibiotics, certain populations have sufficiently high risk of bacteremia and extraintestinal complications that treatment is mandatory:

Absolute Indications for Antibiotic Treatment:

• Infants under 3 months of age (bacteremia risk 45% in neonates, 11% in older infants, with high risk of meningitis and osteomyelitis) 1
• All immunocompromised patients, including HIV/AIDS, transplant recipients, chronic immunosuppression, or malignancy 1
• Documented bacteremia or sepsis with fever ≥38.5°C or signs of severe invasive disease 1
• Pregnant women due to risk of placental infection and pregnancy loss 1

Antibiotic Regimens When Treatment Is Indicated

For adults requiring treatment, ciprofloxacin 500 mg orally twice daily for 7-14 days is first-line therapy 1. This fluoroquinolone approach is preferred because it has the strongest evidence base 4, 3.

Alternative Regimens:

• Azithromycin as an alternative based on local resistance patterns 1
• Ceftriaxone 2 g IV once daily plus ciprofloxacin for immunocompromised adults or severe invasive disease until susceptibilities are available 1
• TMP-SMX or expanded-spectrum cephalosporins (ceftriaxone or cefotaxime) depending on antibiotic susceptibility 4

Treatment Duration Considerations:

• 7-14 days for patients with mild gastroenteritis and CD4+ counts >200 cells/µL 4
• 2-6 weeks for advanced HIV disease (CD4+ count <200 cells/µL) 4
• Long-term suppressive therapy may be needed for HIV-infected patients with septicemia to prevent recurrence 3

Common Pitfalls to Avoid

Do not treat healthy adults with antibiotics "just to be safe"—this increases adverse effects, prolongs carriage, and promotes antibiotic resistance without providing clinical benefit 2.

Do not withhold antibiotics from high-risk populations—the risk of bacteremia in infants under 3 months reaches 45%, and immunocompromised patients have high mortality risk from disseminated disease 1.

Avoid fluoroquinolones in children under 18 years due to cartilage toxicity risk; use TMP-SMX, ceftriaxone, cefotaxime, or ampicillin instead based on susceptibility 5.

Infection Control Measures

Hand hygiene with soap and water (not alcohol-based sanitizers) after toilet use, before food preparation, and after animal contact is essential to prevent spread 1, 3.

Exclude patients from swimming and water activities until diarrhea resolves 1.