Background: Group B streptococcus (GBS) is a leading neonatal sepsis pathogen globally. Investment in GBS disease prevention, such as maternal vaccination, requires evidence of disease burden, particularly in high infant mortality regions like sub-Saharan Africa. We aimed to provide such evidence by conducting a systematic literature review and meta-analysis to estimate maternal colonization proportion, GBS disease incidence and GBS serotype distribution.
Methods: MEDLINE, MEDLINE in process and Cochrane Library were searched for studies published during 1990–2014, pertaining to sub-Saharan Africa. Eligible studies were used to estimate the proportion of pregnant women colonized with GBS, early-onset GBS disease incidence, late-onset GBS disease incidence and respective serotype distributions. Random effects meta-analysis was conducted to estimate weighted means and confidence intervals (CIs).
Results: We identified 17 studies of colonization, 9 of disease incidence, and 6 of serotype distribution meeting inclusion criteria. 21.8% (95% CI: 18.3, 25.5) of expectant women were colonized with GBS. The incidence of early-onset GBS disease was 1.3 per 1000 births (95% CI: 0.81, 1.9), that of late-onset GBS disease 0.73 per 1000 births (95% CI: 0.48, 1.0). The most common disease-causing serotype was 3, followed by 1a. Serotypes 1b, 2 and 5 were next most common in frequency.
Conclusion: Despite methodological factors leading to underestimation, GBS disease incidence appears high in sub-Saharan Africa. A small number of GBS serotypes cause almost all disease. GBS disease burden in sub-Saharan Africa suggests that safe, effective and affordable GBS disease prevention is needed.
From the *Department of Health Systems and Policy, Rutgers School of Public Health, Newark, New Jersey; †Institute for Health, Health Care Policy, and Aging Research, Rutgers - The State University of New Jersey, New Brunswick, New Jersey; ‡Division of Bacterial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia; §KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya & Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, United Kingdom; ¶College of Medicine and Health Sciences, Hawassa University, Hawassa, Ethiopia; ‖Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique; and **Division of Management, Policy and Community Health University of Texas School of Public Health, San Antonio, Texas.
Accepted for publication February 7, 2016.
N.H., R.S.H. and S.A.M. have received funding for a GBS vaccine trial from Novartis Vaccines and Diagnostics, Inc. S.A.M. has received honoraria for advisory board participation from Pfizer, Inc. This study was supported by award OPP1105076 from the Bill and Melinda Gates Foundation.
The GBS Vaccine Cost-Effectiveness Analysis in sub-Saharan Africa Working Group authors are listed in the Acknowledgments.
The authors have no conflicts of interest to disclose.
Address for correspondence: Anushua Sinha, MD, MPH, Department Health Systems and Policy, Rutgers School of Public Health, Rutgers - The State University of New Jersey, MSB F506, 185 South Orange Avenue, Newark, NJ 07101. E-mail: firstname.lastname@example.org.