Table 3.
Prevalence of isolates resistant to azithromycin in newborns and mothers in the different study samples
| Day 0a |
Day 3 |
Day 6b |
Day 14 |
Day 28 |
||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| P'bo (%) | AZI (%) | PR (95% CI) | p value | P'bo (%) | AZI (%) | PR (95% CI) | p value | P'bo (%) | AZI (%) | PR (95% CI) | p value | P'bo (%) | AZI (%) | PR (95% CI) | p value | P'bo (%) | AZI (%) | PR (95% CI) | p value | |
| NPS newborn | n = 416 | n = 417 | n = 396 | n = 386 | n = 387 | n = 378 | n = 381 | n = 372 | n = 374 | n = 359 | ||||||||||
| GBS | 0 | 0 | NA | NA | 0.5 | 0 | NA | NA | 0.5 | 0.3 | 0.51 (0.05–5.62) | 1 | 0.3 | 0.3 | 1.02 (0.06–16.31) | 1 | 0.0 | 0.3 | NA | NA |
| Streptococcus pneumoniae | 0 | 0 | NA | NA | 0 | 0 | NA | NA | 0.5 | 0 | NA | 0.499 | 1.0 | 0.5 | 0.51 (0.009–2.78) | 0.686 | 2.1 | 2.2 | 1.04 (0.40–2.75) | 1 |
| Staphylococcus aureus | 1.0 | 0.7 | 0.77 (0.17–3.40) | 1 | 6.8 | 10.6 | 1.56 (0.98–2.48) | 0.075 | 5.2 | 12.7 | 2.46 (1.49–4.06) | <0.001 | 3.4 | 15.3 | 4.49 (2.50–8.06) | <0.001 | 4.5 | 16.7 | 3.68 (2.19–6.18) | <0.001 |
| Any bacteria | 1.0 | 0.7 | 0.77 (0.17–3.40) | 1 | 7.3 | 10.6 | 1.45 (0.92–2.28) | 0.132 | 6.2 | 13.0 | 2.09 (1.31–3.34) | 0.002 | 4.5 | 16.1 | 3.61 (2.15–6.08) | <0.001 | 6.7 | 19.2 | 2.88 (1.86–4.44) | <0.001 |
| NPS mother | n = 415 | n = 414 | n = 402 | n = 400 | n = 397 | n = 395 | n = 390 | n = 390 | n = 386 | n = 381 | ||||||||||
| GBS | 0 | 0 | NA | NA | 0 | 0 | NA | NA | 0 | 0 | NA | NA | 0 | 0 | NA | NA | 0..3 | 0.3 | 1.01 (0.06–16.1) | 1 |
| S. pneumoniae | 0 | 1.4 | NA | NA | 0.5 | 0.8 | 1.51 (0.25–8.97) | 0.686 | 1.0 | 0.8 | 0.75 (0.17–3.35) | 1 | 0.8 | 1.8 | 2.33 (0.61–8.96) | 0.341 | 0.3 | 1.8 | 7.09 (0.88–57.4) | 0.037 |
| S. aureus | 2.7 | 1.4 | 0.55 (0.20–1.46) | 0.327 | 1.7 | 4.0 | 2.30 (0.96–8.97) | 0.686 | 3.5 | 5.6 | 1.58 (0.82–3.04) | 0.177 | 3.1 | 9.2 | 3.00 (1.85–5.68) | <0.001 | 2.8 | 12.6 | 4.42 (2.33–8.38) | <0.001 |
| Any bacteria | 2.7 | 2.9 | 1.09 (0.49–2.45) | 0.836 | 2.2 | 4.8 | 2.12 (0.97–4.63) | 0.057 | 4.3 | 6.3 | 1.48 (0.81–2.69) | 0.209 | 3.8 | 10.5 | 2.73 (1.54–4.86) | <0.001 | 3.4 | 14.7 | 4.36 (2.43–7.85) | <0.001 |
| Breast milk | n = 0 | n = 0 | n = 399 | n = 394 | n = 397 | n = 385 | n = 387 | n = 388 | n = 384 | n = 381 | ||||||||||
| GBS | — | — | — | — | 0.5 | 0.3 | 0.51 (0.05–5.56) | 1 | 0.5 | 0.3 | 0.50 (0.05–5.52) | 1 | 0.3 | 0.3 | 1.00 (0.006–15.9) | 1 | 0 | 0 | NA | NA |
| S. pneumoniae | — | — | — | — | 0 | 0 | NA | NA | 0 | 0 | NA | NA | 0 | 0.0 | NA | NA | 0 | 0 | NA | NA |
| S. aureus | — | — | — | — | 1.8 | 4.8 | 2.75 (1.17–6.47) | 0.017 | 2.0 | 5.1 | 2.51 (1.12–5.64) | 0.021 | 0.8 | 5.7 | 7.31 (2.21–24.2) | <0.001 | 1.3 | 3.7 | 2.82 (1.03–7.76) | 0.038 |
| Any bacteria | — | — | — | — | 2.3 | 5.1 | 2.25 (1.04–4.88) | 0.038 | 2.5 | 5.3 | 2.11 (1.01–4.42) | 0.045 | 1.0 | 5.9 | 5.74 (2.00–16.4) | <0.001 | 1.3 | 3.7 | 2.82 (1.03–7.76) | 0.038 |
| Vaginal swabs | n = 415 | n = 414 | n = 0 | n = 0 | n = 396 | n = 386 | n = 0 | n = 0 | n = 0 | n = 0 | ||||||||||
| GBS | 0.5 | 0.2 | 0.50 (0.05–5.51) | 1 | — | — | — | — | 0.3 | 1.5 | 6.06 (0.73–50.1) | 0.068 | — | — | — | — | — | — | — | — |
| S. pneumoniae | 0 | 0 | NA | NA | — | — | — | — | 0 | 0 | NA | NA | — | — | — | — | — | — | — | — |
| S.aureus | 1.7 | 0 | NA | NA | — | — | — | — | 1.0 | 6.9 | 6.82 (2.41–19.3) | <0.001 | — | — | — | — | — | — | — | — |
| Any bacteria | 2.2 | 0.2 | 0.11 (0.01–0.88) | 0.021 | — | — | — | — | 1.3 | 8.4 | 6.67 (2.63–16.9) | <0.001 | — | — | — | — | — | — | — | — |
Abbreviations: AZI, azithromycin; GBS, group B streptococci; NPS, nasopharyngeal swab; P'bo– placebo; PR, Prevalence Ratio.
Azithromycin resistance was determined by E-test following the CLSI 2014 guidelines for the performance of test and interpretation of results:
(i) S. aureus isolates with E-test values ≥8 μg/mL
(ii) S. pneumoniae/GBS isolates with E-test values ≥2 μg/mL.l
a
At day 0, nasopharyngeal and vaginal swabs in mothers were collected before the intervention and nasopharyngeal swabs in newborns after the intervention.
b
Vaginal swab was collected at day 8–10 instead.