What is the management and treatment of Strep (Streptococcus) agalactiae bacteremia?

From the Guidelines

The management of Streptococcus agalactiae (Group B Streptococcus) bacteremia requires prompt antibiotic therapy with penicillin G as the first-line treatment, typically administered at 5 million units IV initial dose, then 2.5 million units IV every 4 hours until delivery, as recommended for pregnant women 1. For non-pregnant adults, the treatment duration and dosage may vary, but penicillin G remains the preferred choice due to its narrow spectrum of activity and the natural susceptibility of Group B Streptococcus to penicillins. In cases of penicillin allergy, alternative regimens such as cefazolin, clindamycin, or vancomycin may be considered, depending on the severity of the allergy and the susceptibility of the isolate 1. It is crucial to identify the source of bacteremia, which can include urinary tract infections, skin and soft tissue infections, or the genital tract in pregnant women. Blood cultures should be repeated to confirm clearance of bacteremia, and echocardiography may be necessary to rule out endocarditis, especially in patients with persistent fever or new heart murmurs. Supportive care, including IV fluids and vasopressors, may be necessary for patients with sepsis. Consultation with infectious disease specialists is recommended for complicated cases, particularly those involving endocarditis, meningitis, or recurrent bacteremia. The most recent guidelines from the CDC, although focused on the prevention of perinatal Group B Streptococcal disease, emphasize the importance of prompt and appropriate antibiotic therapy in managing Group B Streptococcus infections 1.

Key considerations in the management of Streptococcus agalactiae bacteremia include:

• Prompt initiation of antibiotic therapy with penicillin G for pregnant women, as outlined in the CDC guidelines 1
• Identification of the source of bacteremia and appropriate management
• Monitoring for complications such as endocarditis and sepsis
• Consideration of alternative antibiotic regimens for patients with penicillin allergy
• Consultation with infectious disease specialists for complicated cases

Given the potential severity of Group B Streptococcus infections, particularly in vulnerable populations such as newborns and pregnant women, it is essential to follow established guidelines and consult recent evidence to ensure the best possible outcomes in terms of morbidity, mortality, and quality of life.

From the FDA Drug Label

Serious infections, such as pneumonia and endocarditis, due to susceptible strains of streptococci (including S pneumoniae) and meningococcus 150,000 - 300,000 units/kg/day divided in equal doses every 4 to 6 hours; duration depends on infecting organism and type of infection Meningitis caused by susceptible strains of pneumococcus and meningococcus 250,000 units/kg/day divided in equal doses every 4 hours for 7 to 14 days depending on the infecting organism (maximum dose of 12 to 20 million units/day)

The management and treatment of Strep (Streptococcus) agalactiae bacteremia involves the administration of penicillin G (IV) at a dosage of 150,000 - 300,000 units/kg/day divided into equal doses every 4 to 6 hours, with the duration of treatment depending on the infecting organism and type of infection 2.

• Key considerations:
  • The dosage may vary depending on the severity of the infection and the patient's response to treatment.
  • Treatment should be continued for at least 48 to 72 hours after the patient becomes asymptomatic or evidence of bacterial eradication has been obtained.
  • In cases of Group A beta-hemolytic streptococcal infections, treatment should be continued for at least 10 days to help prevent the occurrence of acute rheumatic fever or acute glomerulonephritis.

From the Research

Management and Treatment of Strep Agalactiae Bacteremia

• The management and treatment of Strep agalactiae bacteremia typically involve the use of antibiotics, with Penicillin G being the first-line treatment 3, 4.
• For patients allergic to penicillin, alternative antibiotics such as Erythromycin, Vancomycin, and Clindamycin may be used 3, 5.
• However, there is a growing concern about the increasing resistance of Strep agalactiae to these alternative antibiotics, particularly Erythromycin and Clindamycin 3, 6, 5.
• Vancomycin is often used as a last resort for patients who are allergic to penicillin and have resistance to other antibiotics 3, 6.

Antibiotic Resistance and Susceptibility

• Studies have shown that Strep agalactiae is still universally susceptible to beta-lactam antibiotics, such as Penicillin G 6.
• However, there have been reports of reduced susceptibility to beta-lactams, including Penicillin, in some countries 6.
• Resistance to second-line antibiotics, such as Erythromycin and Clindamycin, remains high amongst Strep agalactiae, with several countries noting increased resistance rates in recent years 3, 6, 5.

Clinical Manifestations and Prognostic Factors

• Strep agalactiae bacteremia can present with various clinical manifestations, including primary bacteremia, arthritis, cellulitis, meningitis, osteomyelitis, and endocarditis 4.
• Prognostic factors associated with mortality include age, underlying medical conditions, alteration of consciousness, absence of fever, high Pitt bacteremia score, and shock 4.
• Penicillin G treatment has been identified as a protective factor against mortality in patients with Strep agalactiae bacteremia 4.

Intrapartum Antibiotic Prophylaxis

• Intrapartum antibiotic prophylaxis (IAP) is the current gold standard for preventing neonatal sepsis in Strep agalactiae-positive mothers 7.
• The management of IAP varies by obstetric ward and is based on various national and international guidelines, with a need for enhanced interdisciplinarity and a joint national guideline among professional societies 7.