Skip to main content

Table 2 Colonisation rates (%) and 95% confidence intervals by gestational age and swab sitea. Using selective broth

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