What is the treatment for enteropathogenic Escherichia coli (E. coli) infection in pregnancy?

Treatment of Enteropathogenic E. coli in Pregnancy

For enteropathogenic Escherichia coli (EPEC) infection during pregnancy, trimethoprim-sulfamethoxazole (TMP-SMX) is the recommended first-line treatment if the organism is susceptible, with alternative options including cephalosporins or azithromycin when TMP-SMX cannot be used. 1

First-Line Treatment Options

For Susceptible Strains:

• TMP-SMX: 160/800 mg twice daily for 3 days 1
  • Note: When using TMP-SMX in pregnancy, inform neonatal care providers if used near delivery due to theoretical risk of hyperbilirubinemia and kernicterus to the newborn 1

For Patients Who Cannot Take TMP-SMX:

1. Cephalosporins (expanded spectrum) 1

   • Safe in all trimesters of pregnancy
   • Options include ceftriaxone or cefuroxime

2. Azithromycin 1

   • Particularly useful if resistance to TMP-SMX is suspected

Treatment Algorithm Based on Pregnancy Trimester

First Trimester:

• Preferred: Cephalosporins (expanded spectrum) 1
• Alternative: Azithromycin if cephalosporins cannot be used 1
• Avoid if possible: Fluoroquinolones due to potential risks in animal studies 1, 2

Second and Third Trimesters:

• First choice: TMP-SMX if susceptible 1
• Alternatives: Cephalosporins or azithromycin 1

Special Considerations

Severe Infection/Bacteremia:

• Hospitalization with IV antibiotics may be necessary
• Initial therapy: Expanded spectrum cephalosporins 1
• Duration: 10-14 days for bacteremia without endocarditis 3

Monitoring During Treatment:

• Assess clinical response within 48-72 hours of starting treatment 3
• If symptoms persist, consider:
  1. Repeat cultures
  2. Imaging to rule out complications
  3. Evaluation for underlying abnormalities

Important Cautions

1. Avoid fluoroquinolones when possible: While approximately 400 cases of quinolone use in pregnancy have been reported without association with arthropathy or birth defects, they should be used only when benefits outweigh risks 1, 2

2. Maternal E. coli infection risks: Associated with increased incidence of preterm premature rupture of membranes, miscarriages before 28 weeks, and fetal distress during labor 4

3. Primiparity and higher BMI: Independent risk factors for E. coli infection during pregnancy (odds ratio = 2.981 and 1.149 respectively) 4

4. For enterohemorrhagic E. coli (STEC): Avoid antimotility drugs and antibiotics may be contraindicated as they can increase Shiga toxin production 1

Duration of Treatment

• Uncomplicated infection: 3-5 days 1
• Complicated infection: 10-14 days 3
• Bacteremia: 10-14 days after resolution of signs of infection 3

Prevention of Recurrence

• Regular prenatal screening for asymptomatic bacteriuria is recommended
• Proper hygiene practices
• Adequate hydration during pregnancy
• Prompt treatment of initial infection to prevent complications

E. coli infections during pregnancy require prompt treatment due to the increased risk of adverse maternal and fetal outcomes, including preterm labor and delivery 5. The choice of antibiotic should balance efficacy against the organism with safety for both mother and fetus.