Findings
Introduction
Materials and methods
Study design
SBA, CNA, and SCB methods
Latex agglutination test method
PCR analysis
Statistical analysis
Results
Latex agglutination test result of SBA method
Density level of GBS (c.f.u. per swab) | No. of samples tested positive (n) | No. of samples positive for GBS (n) | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) |
---|---|---|---|---|---|---|
High (>100) | 22 | 22 | 22/22 (100 %) | 22/22 (100 %) | 22/22 (100 %) | 22/22 (100 %) |
Moderate (50–100) | 27 | 27 | 27/27 (100 %) | 27/27 (100 %) | 27/27 (100 %) | 27/27 (100 %) |
Low (10–50) | 24 | 36 | 24/36 (66.7 %) | 36/36 (100 %) | 24/24 (100 %) | 36/48 (75.0 %) |
Little (<10) | 2 | 15 | 2/15 (13.3 %) | 15/15 (100 %) | 2/2 (100 %) | 15/28 (53.6 %) |
SBA, CNA, and SCB followed by latex agglutination test
Culture medium | GBS positive samples (n) | Vaginal swabs (n =200) | |
---|---|---|---|
GBS isolation rate (%) | Sensitivity (%)a
| ||
SBA | 12 | 6.0 | 57.1 |
CNA | 16 | 8.0 | 76.0 |
SCB | 20 | 10.0 | 95.2 |
True positive GBS cultures | 21 | 10.5 |
Culture medium | Level of GBS density (c.f.u. per swab) | No. of samples tested positive (n) | No. of samples positive for GBS (n) | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) |
---|---|---|---|---|---|---|---|
SBA | High (>100) | 3 | 3 | 100 | 100 | 100 | 100 |
Moderate (50–100) | 4 | 4 | 100 | 100 | 100 | 100 | |
Low (10–50) | 3 | 5 | 60 | 100 | 100 | 71.4 | |
Little (<10) | 0 | 0 | / | / | / | / | |
CNA | High (>100) | 3 | 3 | 100 | 100 | 100 | 100 |
Moderate (50–100) | 5 | 5 | 100 | 100 | 100 | 100 | |
Low (10–50) | 4 | 7 | 57.1 | 100 | 100 | 70 | |
Little (<10) | 0 | 1 | 0 | 100 | 100 | 50 | |
SCB | High (>100) | 15 | 15 | 100 | 100 | 100 | 100 |
Moderate (50–100) | 5 | 5 | 100 | 100 | 100 | 100 | |
Low (10–50) | 0 | 0 | / | / | / | / | |
Little (<10) | 0 | 0 | / | / | / | / |