From: Antenatal screening for Group B Streptococcus: A diagnostic cohort study
Swab site | 32 weeks gestation | 36 weeks gestation | Labour | |||
---|---|---|---|---|---|---|
a. Using selective broth | ||||||
Prevalence | 95 % CI | Prevalence | 95% CI | Prevalence | 95% CI | |
Low Vaginal Swab (LVS) | 19 | 16–21 | 20 | 17–23 | 21 | 18–24 |
Perianal Swab (PAS) | 21 | 18–24 | 22 | 19–25 | 22 | 19–25 |
Either LVS or PAS | 22 | 19–25 | 24 | 21–26 | 24 | 21–27 |
b. Removing "scanty" levels of colonisation as would occur in the absence of selective broth | ||||||
Swab site | 32 weeks gestation | 36 weeks gestation | Labour | |||
Prevalence | 95 % CI | Prevalence | 95% CI | Prevalence | 95% CI | |
Low Vaginal Swab (LVS) | 14 | 11–16 | 15 | 13–18 | 17 | 14–20 |
Perianal Swab (PAS) | 15 | 12–18 | 15 | 12–17 | 16 | 13–19 |
Either LVS or PAS | 17 | 15–20 | 18 | 16–21 | 20 | 17–23 |