From the Guidelines
The management of Streptococcus agalactiae bacteremia in pregnant women requires prompt antibiotic therapy, typically with intravenous penicillin G at 5 million units initially, followed by 2.5-3 million units every 4 hours until delivery, as recommended by the most recent guidelines 1. The choice of antibiotic is crucial in managing GBS bacteremia, and penicillin G remains the first-line treatment. For penicillin-allergic patients, alternatives include cefazolin (2g IV loading dose, then 1g every 8 hours) or, in cases of severe penicillin allergy, vancomycin (15-20 mg/kg IV every 8-12 hours) 1.
Key Considerations
- Treatment should continue for at least 10 days for uncomplicated bacteremia.
- Intrapartum antibiotic prophylaxis is essential during delivery to prevent vertical transmission to the newborn, regardless of whether bacteremia was previously treated.
- Blood cultures should be repeated to confirm clearance of the infection.
- Close monitoring of both mother and fetus is crucial, with regular assessment of vital signs, laboratory parameters, and fetal well-being.
Special Considerations for Pregnant Women
- GBS bacteremia requires aggressive treatment because the organism can cause serious complications, including endocarditis, meningitis, and preterm labor.
- GBS is a leading cause of neonatal sepsis, making effective maternal treatment essential for both maternal and fetal outcomes.
- After recovery, all pregnant women should still receive standard GBS screening at 36-37 weeks gestation as colonization status can change 1.
Antibiotic Prophylaxis for High-Risk Infants
- Infants born earlier than 35 weeks’ gestation are at highest risk of early-onset sepsis and early-onset GBS disease.
- Performing a blood culture and starting antibiotic treatment are recommended in infants born earlier than 35 weeks’ gestation, even after sufficient intrapartum antibiotic prophylaxis 1.
From the Research
Management of Strep Agalactiae Bacteremia
- The management of Strep agalactiae bacteremia, particularly in pregnant women, involves the use of antibiotics to prevent neonatal sepsis and maternal morbidity 2, 3, 4, 5, 6.
- According to the American College of Obstetricians and Gynecologists (ACOG) guidelines, penicillin is the first-line antibiotic for the treatment of GBS-positive patients 2.
- For patients with penicillin allergies, alternative antibiotics such as cefazolin, vancomycin, and clindamycin may be used 2, 3, 4, 5, 6.
- However, there is a growing concern about the increasing resistance of GBS to erythromycin and clindamycin, which may limit their use as empirical therapy in patients allergic to penicillin 3, 5, 6.
Antibiotic Susceptibility and Resistance
- Studies have shown that GBS isolates are still universally susceptible to beta-lactam antibiotics such as penicillin, ampicillin, and cefotaxime 3, 5.
- However, there is a high rate of resistance to erythromycin and clindamycin among GBS isolates, particularly in non-pregnant patients 3, 5, 6.
- The use of vancomycin as a last resort antibiotic is still effective, but there have been reports of vancomycin resistance in GBS isolates 5.
Intrapartum Antibiotic Prophylaxis
- Intrapartum antibiotic prophylaxis (IAP) is the current gold standard for preventing neonatal sepsis in GBS-positive mothers 4.
- The choice of antibiotics for IAP varies by hospital and is based on various national and international guidelines 4.
- A study in Switzerland found that the management of IAP is heterogeneous, and antimicrobial stewardship is lacking in most obstetric wards 4.