Clinical Scorecard: Epidemiological Study of Invasive Group B Streptococcus in South Africa from 2019 to 2020
At a Glance
Category
Detail
Condition
Invasive Group B Streptococcus (GBS) infection causing neonatal sepsis, meningitis, and adult disease
Key Mechanisms
Capsular polysaccharide serotypes and surface protein expression; antimicrobial resistance genes
Target Population
Individuals of all ages in South Africa, including neonates, infants, adults, and older people
Care Setting
National laboratory-based surveillance and clinical management in hospital and community settings
Key Highlights
1748 invasive GBS cases reported with 658 isolates characterized by phenotypic and genotypic methods
Predominant serotypes: III (42.8%), Ia (27.9%), V (11.9%), II (8.4%), Ib (6.7%), IV (2.3%)
Low penicillin resistance (only 1 isolate with reduced susceptibility); notable resistance to erythromycin (16.1%), clindamycin (3.8%), and tetracycline (91.5%)
Guideline-Based Recommendations
Diagnosis
Confirm GBS from normally sterile sites using culture and phenotypic methods including colony morphology and β-hemolysis
Use latex agglutination for capsular serotyping (Ia, Ib, II–IX)
Perform antimicrobial susceptibility testing per CLSI guidelines
Management
Use β-lactam antibiotics, primarily penicillin, as first-line treatment for invasive GBS infections
Consider intrapartum antibiotic prophylaxis (IAP) for women at risk of GBS transmission during perinatal period where feasible
Monitor for resistance to second-line agents such as erythromycin and clindamycin
Monitoring & Follow-up
Conduct ongoing national surveillance of invasive GBS isolates for serotype distribution and antimicrobial susceptibility
Perform whole-genome sequencing to track population structure, resistance genes, and vaccine target proteins
Risks
Potential for emergence of penicillin-nonsusceptible GBS strains
Increasing resistance to erythromycin and clindamycin may limit alternative treatment options
Challenges in implementing IAP in resource-limited settings may increase neonatal early-onset disease risk
Patient & Prescribing Data
All age groups in South Africa with invasive GBS disease
Penicillin remains effective with very low resistance; erythromycin and clindamycin resistance present in a subset; tetracycline resistance widespread but less clinically relevant
Clinical Best Practices
Use penicillin as first-line therapy for invasive GBS infections
Implement intrapartum antibiotic prophylaxis in perinatal care where possible to reduce early-onset neonatal disease
Perform serotyping and antimicrobial susceptibility testing to guide epidemiological surveillance and treatment decisions
Support development and future implementation of polysaccharide and protein-based GBS vaccines targeting predominant serotypes and surface proteins
by Buhle Ntozini, Sibongile Walaza, Benjamin Metcalf, Scott Hazelhurst, Linda de Gouveia, Susan Meiring, Dineo Mogale, Senzo Mtshali, Arshad Ismail, Kedibone Ndlangisa, Mignon Du Plessis, Vanessa Quan, Sopio Chochua, Lesley McGee, Anne von Gottberg, Nicole Wolter
