Prevalence, Risk Factors, and Serotype Distribution of Group B Streptococcus Colonization in HIV-Infected Pregnant Women Living in Belgium: A Prospective Cohort Study

• Published in: Open forum infectious diseases Vol. 5; no. 12; p. ofy320
• Main Authors: Dauby, Nicolas, Adler, Catherine, Miendje Deyi, Veronique Y, Sacheli, Rosalie, Busson, Laurent, Chamekh, Mustapha, Marchant, Arnaud, Barlow, Patricia, De Wit, Stéphane, Levy, Jack, Melin, Pierrette, Goetghebuer, Tessa
• Format: Journal Article Web Resource
• Language: English
• Published: United States Oxford University Press 01-12-2018
• Subjects: GBS; HIV infections; Life sciences; Major; Microbiologie; Microbiology; Sciences du vivant; multilocus sequence typing; Streptococcus agalactiae; HIV infection; serotype; pregnancy
• ISSN: 2328-8957; 2328-8957
• DOI: 10.1093/ofid/ofy320

Group B streptococcus (GBS) infection is a leading cause of severe neonatal infection. Maternal GBS carriage during pregnancy is the main risk factor for both early-onset and late-onset GBS disease. High incidence of GBS infection has been reported in HIV-exposed but -uninfected infants (HEU). We aimed to determine the prevalence, characteristics, and risk factors for GBS colonization in HIV-infected and HIV-uninfected pregnant women living in Belgium.
Between January 1, 2011, and December 31, 2013, HIV-infected (n = 125) and -uninfected (n = 120) pregnant women had recto-vaginal swabs at 35-37 weeks of gestation and at delivery for GBS detection. Demographic, obstetrical, and HIV infection-related data were prospectively collected. GBS capsular serotyping was performed on a limited number of samples (33 from HIV-infected and 16 from HIV-uninfected pregnant women).
There was no significant difference in the GBS colonization rate between HIV-infected and -uninfected pregnant women (29.6% vs 24.2%, respectively). HIV-infected women were more frequently colonized by serotype III (36.4% vs 12.5%), and the majority of serotype III strains belonged to the hypervirulent clone ST-17. Exclusively trivalent vaccine serotypes (Ia, Ib, and III) were found in 57.6% and 75% of HIV-infected and -uninfected women, respectively, whereas the hexavalent vaccine serotypes (Ia, Ib, II, III, IV, and V) were found in 97% and 100%, respectively.
HIV-infected and -uninfected pregnant women living in Belgium have a similar GBS colonization rate. A trend to a higher colonization rate with serotype III was found in HIV-infected women, and those serotype III strains belong predominantly to the hypervirulent clone ST17.