What is Salmonella infection?

From the Guidelines

Salmonella infection should be treated with a fluoroquinolone, such as ciprofloxacin, as the initial treatment of choice, especially in severe cases or in patients with weakened immune systems, as recommended by the CDC and the Infectious Diseases Society of America 1.

Treatment Approach

The treatment approach for Salmonella infection typically involves rest and hydration, as most cases resolve within 4-7 days without antibiotics. However, for severe cases, antibiotics like ciprofloxacin (500mg twice daily for 5-7 days) or azithromycin (500mg once daily for 3-5 days) may be prescribed.

• The length of therapy for HIV-related Salmonella infection is poorly defined, but 7-14 days of treatment is reasonable for patients with mild gastroenteritis, while a longer course of antibiotics (e.g., 2-6 weeks) may be recommended for patients with advanced HIV disease 1.
• The choice of antimicrobial agent may change due to evolving resistance patterns, and fluoroquinolone resistance in US and Canadian patients without international travel remains low, but is significantly higher in many commonly visited countries 1.

Prevention and Risk Factors

To prevent Salmonella, it is essential to:

• Thoroughly cook meat, poultry, and eggs
• Wash hands and surfaces after handling raw foods
• Avoid cross-contamination between raw and cooked foods
• Refrigerate perishable foods promptly Symptoms of Salmonella infection typically include diarrhea, abdominal cramps, fever, and sometimes vomiting, appearing 6-72 hours after exposure. Those at higher risk for severe infection include young children, older adults, pregnant women, and people with weakened immune systems.

Special Considerations

In adults, bloody diarrhea can be due to infectious and noninfectious causes, and the presence of fever, abdominal pain, or vomiting is more suggestive of infection, which in these cases is likely to be due to an invasive/inflammatory pathogen, such as Salmonella, Campylobacter, C. difficile, Shigella, or STEC 1.

• Several RCTs have demonstrated a small but significant benefit for antimicrobial therapy in reducing the duration of symptoms in Campylobacter gastroenteritis, and it is reasonable to treat patients with particularly prolonged or severe disease, as well as immunocompromised patients with otherwise uncomplicated Campylobacter gastroenteritis 1.

From the Research

Overview of Salmonella

• Salmonellosis in humans is most often manifested as a self-limiting gastroenteritis 2
• Antimicrobial therapy is superfluous in the milder forms of the disease and in Salmonella carriage but can be life saving for patients with septic salmonellosis and patients at risk of extraintestinal dissemination of the infection 2

Treatment Options

• The drugs of choice for empiric treatment of acute infectious diarrhea, in which Salmonella spp are etiologically implicated, are fluoroquinolones in adults and third generation cephalosporins in children 2
• Alternative treatment may use azithromycin and imipenem in life-threatening systemic Salmonella infections 2
• Aminoglycosides are considered ineffective in gastrointestinal salmonelloses 2
• Azithromycin at a dose of 500mg daily is an effective treatment for fully sensitive strains of S. Typhi but is associated with delayed treatment response and prolonged bacteraemia when compared with ciprofloxacin 3

Antibiotic Resistance

• The emerging resistance to fluoroquinolones, production of extended-spectrum beta-lactamases, and the increase of multidrug resistant Salmonella strains are major problems in the search for efficient antimicrobial therapy of Salmonella infection 2
• Patients with antimicrobial-resistant nontyphoidal Salmonella infections have more severe outcomes, including increased risk of bloodstream infection and hospitalization 4

Clinical Outcomes

• There appears to be no evidence of a clinical benefit of antibiotic therapy in otherwise healthy children and adults with non-severe salmonella diarrhoea 5
• Antibiotics appear to increase adverse effects and they also tend to prolong salmonella detection in stools 5
• Combination therapy with cefotaxime and ciprofloxacin may be considered as an option for difficult-to-treat salmonellosis 6