opTImisation of Methods for a human INfection model for Group B streptococcus (TIMING)

This study investigated longitudinal variation in GBS rectovaginal colonization, serum and vaginal GBS capsular polysaccharide (CPS)-specific antibody levels. Women will be recruited for screening for GBS in the UK and Uganda (250 at each site). At screening women will be consented for a vaginal and rectal swab to assess for GBS carriage and will also undergo an asymptomatic STI screen according to local usual practice. In both the UK and Uganda this screening will look for Chlamydia, Gonorrhoea, Trichomonas vaginalis, Bacterial Vaginosis, Candida and for Syphilis, HIV and Hepatitis B and C. Anyone who meets the full inclusion criteria following screening will be invited to take part in the sampling study until the recruitment targets are reached for each cohort: 50 GBS colonised and 50 GBS uncolonised women in each country. The recruited women were sampled every 2 weeks over a 12-week period. GBS isolates were taken from recto-vaginal swabs and serotyped by polymerase chain reaction. Serum and vaginal immunoglobulin G (IgG) and nasal immunoglobulin A (IgA) specific to CPS were measured by Luminex, and total IgG/A by ELISA.