From the Guidelines
Azithromycin is the recommended first-line treatment for Shigella and enteroinvasive E. coli infections, particularly in cases of dysentery or when fluoroquinolone resistance is suspected. The decision to treat these infections with antibiotics is based on the severity of illness and the potential impact on the patient's activities and plans. According to the guidelines for the prevention and treatment of travelers' diarrhea, azithromycin has been shown to be effective in achieving clinical cure in patients with dysentery, including those infected with Shigella spp. and enteroinvasive E. coli 1.
The 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea also recommend azithromycin as the first-line treatment for Shigella infections, with ciprofloxacin or ceftriaxone as alternative options 1. Azithromycin is generally well-tolerated, with minimal side effects, and has been shown to be effective in reducing symptom duration and preventing complications.
Key considerations in the selection of an empiric antibiotic include the likelihood of treatment efficacy, regional patterns of probable target pathogens and their antimicrobial resistance, safety and tolerance profile of the antibiotic, and cost. In areas with high rates of fluoroquinolone resistance, azithromycin is a preferred option.
Some important points to consider when treating Shigella and enteroinvasive E. coli infections include:
- Maintaining hydration with oral rehydration solutions or IV fluids for severe cases
- Rest and a bland diet during recovery
- Avoiding antimotility agents, which can worsen the infection
- Completing the full course of antibiotics even if symptoms improve
- Seeking medical attention if symptoms worsen or persist
Overall, the treatment of Shigella and enteroinvasive E. coli infections requires careful consideration of the severity of illness, potential antibiotic resistance, and the patient's overall health status. Azithromycin is a recommended first-line treatment option due to its efficacy, safety, and tolerability 1.
From the FDA Drug Label
Infectious Diarrhea caused by Escherichia coli (enterotoxigenic strains), Campylobacter jejuni, Shigella boydii†, Shigella dysenteriae, Shigella flexneri or Shigella sonnei† when antibacterial therapy is indicated.
The treatment for Shigella (Shigella) enteroinvasive Escherichia coli (E. coli) is ciprofloxacin (PO), as it is indicated for the treatment of infectious diarrhea caused by Shigella species and Escherichia coli (enterotoxigenic strains) when antibacterial therapy is indicated 2.
From the Research
Treatment Options for Shigella and Enteroinvasive E. coli
- Azithromycin is effective in the treatment of moderate to severe shigellosis caused by multidrug-resistant Shigella strains 3.
- Azithromycin is the preferred first-line antibiotic for the treatment of acute watery diarrhea and febrile diarrhea/dysentery, with a single dose of 500 mg for acute watery diarrhea and a single dose of 1,000 mg for febrile diarrhea and dysentery 4.
- Ciprofloxacin and levofloxacin are also options for acute watery diarrhea and febrile diarrhea/dysentery, but their effectiveness is decreasing due to increasing fluoroquinolone resistance 4.
- Loperamide can be used in combination with antibiotic treatment to further reduce gastrointestinal symptoms and duration of illness 5.
- Ceftriaxone and moxifloxacin may promote mutant selection in Shigella strains, while azithromycin is predicted to restrict selective enrichment of mutants 6.
Antibiotic Resistance and Treatment
- Shigella strains are developing resistance to various antibiotics, including trimethoprim, with 62.8% of isolates resistant to trimethoprim in one study 7.
- The use of alternative antimicrobial agents should be considered for empirical antibiotic therapy due to the high prevalence of transferable trimethoprim resistance in Shigella isolates 7.
- Fluoroquinolones, such as ciprofloxacin and levofloxacin, are effective against Shigella strains, but their use may select for resistant mutants 6.