Simultaneous carriage of multiple serotypes of Group B Streptococcus: Systematic review and meta-analysis

Background: Epidemiological studies evaluating the distribution of Group B Streptococcus (GBS) serotypes are crucial for serotype-specific vaccine development and post-licensure surveillance. However, there is a paucity of data about the prevalence of simultaneous carriage of multiple serotypes. Methods: We conducted a systematic review of three databases (Medline, Embase, PubMed) to identify studies reporting GBS serotype co-carriage at the same anatomical site (multiple serotypes in one sam-ple) or different anatomical sites (paired samples from one individual with different serotypes). We con-ducted a random-effects meta-analysis to evaluate the prevalence of co-carriage. Results: 18 articles met the inclusion criteria, representing at least 12,968 samples from 14 countries. In a random-effects meta-analysis, we identified that 10 % (95 % CI: 4-19) of the positive samples taken from one anatomical site have more than one serotype, and 11 % (95 % CI: 5-20) of positive participants with samples taken from two anatomical sites carried different serotypes. When reported, the number of ser-otypes simultaneously carried ranged from 1 to 4. The serotypes most often associated with co-carriage are III (20.3 %), V (20.3 %) and Ia (19.5 %). Conclusion: This systematic review demonstrates that co-carriage is a minor but definite phenomenon, but the data are too limited to give a precise picture of the current epidemiology. Co-colonisation detec-tion needs to be taken into consideration in the design and methods of future GBS carriage surveillance studies to estimate and evaluate the potential for serotype replacement once vaccines are introduced. (c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

This study conducted a systematic review of 18 articles and found that multiple serotype carriage in GBS infection is a minor but definite phenomenon. The prevalence of co-carriage was 10% in positive samples from the same anatomical site and 11% in positive participants with samples from different anatomical sites.