1. Context
2. Evidence Acquisition
2.1. Search Strategy
2.2. Inclusion Criteria
2.3. Exclusion Criteria
2.4. Data Collection
2.5. Quality Assessment
2.6. Limitations
2.7. Statistical Analysis
3. Results
3.1. Prevalence of Group B Streptococcus in Iranian Women
| First Author (Ref. No.) | Place (City) | Year (yr) | Age | Pregnancy | Pregnancy Age (wk) | Swab Samples | Identification Method | Sample Size | No. Positive GBS | Carriers (%) | Quality Assessment |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Aali (15) | Kerman | 2005 | 25.6 | Preg | 38-40 | Vag | Cult | 105 | 7 | 6.7 | Low-risk |
| Absalan (16) | Yazd | 2002 | 15-40 | Preg | Recto-Vag | Cult. PCR | 250 | 49 | 19.6 | Low-risk | |
| Ahmadi (17) | Sanandaj | 2017 | 19-43 | Preg | 35-37 | Endocervical | PCR | 109 | 4 | 3.7 | Moderate-risk |
| Akhlaghi (18) | Mashhad | 2007 | NA | Preg | 33-37 | Vag | Cult | 43 | 3 | 7 | Moderate-risk |
| Arzanlou (2) | Ardabil | 2008 | NA | Preg | 35-37 | Recto- Vag | Cult | 420 | 56 | 13.3 | Low-risk |
| Bakhtiari (19) | Tehran | 2011 | NA | Preg | 28-38 | Recto- Vag | Cult. PCR | 375 | 35 | 9.3 | Moderate-risk |
| Bidgani (20) | Ahvaz | 2013-2014 | 16-45 | Preg | 28-38 | Vag | Cult. PCR | 137 | 38 | 27.7 | Moderate-risk |
| Preg | Rect | Cult. PCR | 137 | 42 | 30.7 | Moderate-risk | |||||
| Bornasi (21) | Arak | 2012 | NA | Preg | 35-37 | Vag | Cult. PCR | 500 | 60 | 12 | Moderate-risk |
| Soltan Dalal (22) | Tehran | 2008 | NA | Preg | 35-37 | Recto- Vag | Cult. PCR | 125 | 10 | 8 | Low-Risk |
| Darabi (23) | Tehran | 2014-2015 | 18-35 | Preg | 35-37 | Recto- Vag | Cult | 186 | 22 | 11.8 | Moderate-risk |
| Daramroodi (24) | Kermanshah | 2017 | NA | Preg | 35-37 | Vag | Cult. PCR | 100 | 5 | 5 | Moderate-risk |
| Fatemi (25) | Tehran | 2008 | 16-40 | Preg | 35-37 | Vag | Cult, PCR | 330 | 68 | 20.6 | Moderate-risk |
| Fazeli (26) | Amol | 2013 | NA | Preg | 35-37 | Vag | Cult, PCR | 100 | 4 | 4 | Moderate-risk |
| Rect | Cult, PCR | 100 | 3 | 3 | Moderate-risk | ||||||
| Recto- Vag | Cult, PCR | 100 | 3 | 3 | Moderate-risk | ||||||
| Frouhesh (27) | Tehran | 2011-2012 | NA | Non-preg | - | Urine | Cult | 5000 | 104 | 2.1 | High-risk |
| Ghanbarzadeh (28) | Birjand | 2013-2014 | 16-37 | Preg | 30 | Recto- Vag | Cult | 500 | 26 | 5.2 | Moderate-risk |
| Goudarzi (29) | Khorramabad | 2012 | NA | Preg | 35-37 | Recto- Vag | Cult, Real-time PCR | 100 | 17 | 17 | Moderate-risk |
| Habibzadeh (30) | Ardabil | 2010 | NA | Preg | 35-37 | Vag | Cult | 420 | 19 | 4.5 | Moderate-risk |
| Rect | Cult | 420 | 19 | 4.5 | Moderate-risk | ||||||
| Recto- Vag | Cult | 420 | 24 | 5.7 | Moderate-risk | ||||||
| Hadavand (31) | Tehran | 2010-11 | 15-44 | Preg | 35-37 | Recto- Vag | Cult | 210 | 7 | 3.3 | Moderate-risk |
| Hamedi (32) | Mashhad | 2008-2009 | 15-39 | Preg | 34-40 | Recto- Vag | Cult | 200 | 12 | 6 | Moderate-risk |
| Hassanzadeh (33) | Shiraz | 2006-2007 | 19-35 | Preg | < 20 | Recto- Vag | Cult | 310 | 43 | 13.9 | Low-risk |
| Jannati (2) | Ardabil | 2012 | NA | Preg | 35-37 | Recto- Vag | Cult | 420 | 56 | 13.3 | Moderate-risk |
| Javadi (34) | Isfahan | 2004 | NA | Preg | 35-37 | Recto- Vag | Cult | 170 | 31 | 18.2 | |
| Javanmanesh (35) | Tehran | 2012 | 16-42 | Preg | 35-37 | Recto- Vag | Cult | 1028 | 234 | 22.8 | Low-risk |
| Kabiri (36) | Jahrom | 2014 | 16-40 | Preg | 35-37 | Vag | Cult | 403 | 66 | 16.4 | Low-risk |
| Rect | 21 | 5.2 | Low-risk | ||||||||
| Recto- Vag | 7 | 1.7 | Low-risk | ||||||||
| Kalantar (37) | Sanandaj | 2011-2012 | 18-37 | Preg | 28-38 | Vag | PCR | 200 | 123 | 61.5 | Moderate-risk |
| Rect | PCR | 200 | 160 | 80 | Moderate-risk | ||||||
| Kasraeian (38) | Shiraz | 2007 | 18-36 | Preg | 18 | Urine | Cult | 389 | 1 | 0.3 | Low-risk |
| Khoshkhoutabar (39) | Arak | 2013 | Preg | 35-37 | Recto- Vag | Cult | 268 | 14 | 5.2 | Moderate-risk | |
| Malek-Jafarian (40) | Mashhad | 2015 | 15-40 | Non-preg | Urine Vag | Cult | 1200 | 46 | 3.8 | Moderate-risk | |
| Mansouri (41) | Kerman | 2006-2007 | 20-35 | Preg | 35-37 | Vag | Cult | 602 | 55 | 9.1 | Moderate-risk |
| Mashouf (42) | Hamadan | 2013-2014 | NA | Preg | 35-37 | Vag | Cult. PCR | 203 | 15 | 7.4 | Moderate-risk |
| Mobasheri (43) | Ardal | 2010 | 17-38 | Preg | 0-40 | Vag | Cult | 85 | 2 | 2.3 | Moderate-risk |
| Nakhaei Moghaddam (44) | Mashhad | 2005-2007 | 16-40 | Preg | 35-37 | Vag | Cult | 201 | 22 | 10.9 | Moderate-risk |
| Rect | Cult | 201 | 24 | 11.9 | Moderate-risk | ||||||
| Mohamadi (45) | Ilam, | 2014-2015 | 16-42 | Preg | < 35 | Vag | Cult | 90 | 4 | 4.4 | Moderate-risk |
| Mousavi (46) | Hamadan | 2013-2014 | NA | Preg | 35-37 | Vag | Cult. PCR | 203 | 15 | 7.4 | Moderate-risk |
| Saghafi (47) | Mashhad | 2015-2016 | 15-42 | Preg | 27-37 | Vag | Cult | 200 | 3 | 2 | Moderate-risk |
| Nahaei (13) | Tabriz | 2001-2002 | NA | Preg | NA* | Vag | Cult | 965 | 17 | 1.8 | Moderate-risk |
| Namavar Jahromi (48) | Shiraz | 2003 | 14-45 | Preg | > 24 | Recto- Vag | Cult | 1197 | 110 | 9.2 | Moderate-risk |
| Nasri (49) | Arak | 2010 | 16-39 | Preg | 35-37 | Vag | Cult | 186 | 30 | 16.1 | Moderate-risk |
| Nazari (50) | Yazd | 2015-2016 | 15-40 | Preg | NA | Vag | Cult | 346 | 57 | 16.5 | Moderate-risk |
| Urine | Cult | 346 | 33 | 9.5 | Moderate-risk | ||||||
| Nazer (51) | Khorram Abad | 2009 | 18-39 | Preg | 28-37 | Vag | Cult | 100 | 14 | 14 | Low-risk |
| Pirouz (52) | Tehran | 1992 | 15-43 | Preg | > 37 | Vag | Cult | 200 | 34 | 17 | Moderate-risk |
| Rabiee (53) | Hamadan | 2006 | 18-35 | Preg | > 20 | Vag | Cult | 544 | 145 | 26.7 | Moderate-risk |
| Rahbar (54) | Tehran | 2010 | 26.6 ± 19.37 (mean) | Preg | NA | Urine | Cult | 11800 | 19 | 0.2 | Moderate-risk |
| Non-Preg | - | Urine | Cult | 11800 | 479 | 4.1 | Moderate-risk | ||||
| Sadeh (9) | Yazd | 2013-2014 | 15-40 | Preg | NA | Recto- Vag | Cult. PCR | 237 | 30 | 12.7 | Moderate-risk |
| Non-Preg | - | Recto- Vag | Cult. PCR | 413 | 70 | 16.9 | Moderate-risk | ||||
| Zarean Seyyed (55) | Isfahan | 2010-2011 | 17-42 | Preg | 37 | Rect | Cult | 178 | 30 | 16.9 | Low-risk |
| 17-36 | 20-37 (Preterm labor) | Rect | Cult | 151 | 55 | 36.4 | Low-risk | ||||
| 17-42 | 37 | Vag | Cult | 178 | 36 | 20.2 | Low-risk | ||||
| 17-36 | 20-37 (Preterm labor) | Vag | Cult | 151 | 59 | 39.1 | Low-risk | ||||
| Sharifi (56) | Tehran | 2011 | NA | Preg | 35-37 | Recto- Vag | Cult | 250 | 21 | 8.4 | Moderate-risk |
| Shirazi (57) | Tehran | 2009-2011 | 19-50 | Preg | 35-37 | Vag | Cult | 980 | 48 | 4.9 | Low-risk |
| Tajbakhsh (58) | Bushehr | 2010-2011 | 26.39 ± 5.33 mean | Preg | 35-42 | Vag | Cult | 285 | 27 | 9.5 | Low-risk |
| Yasini (59) | Kashan | 2011-2012 | 16-45 | Preg | 28-37 | Vag | Cult | 382 | 36 | 9.4 | Moderate-risk |
| Zamanzad (60) (unpublished Persian article) | Shahrekord | 2000 | NA | Preg | Vag | Cult | 624 | 110 | 17.6 | Moderate-risk | |
| Amirmozafari (61) | Rasht | 2005 | Preg | 28-37 | Vag | Cult | 100 | 15 | 15 | High-risk | |
| Haghshenas Mojaveri (62) | Babol | 2014 | 25.9 ± 4.2 (mean) | Preg | 35-37 | Vag | Cult | 400 | 31 | 7.8 | Low-risk |
| Rect | Cult | 400 | 20 | 5 | Low-risk | ||||||
| Recto- Vag | Cult | 400 | 10 | 2.5 | Low-risk | ||||||
| Jahed (63) | Tehran | 2008 | NA | Preg | 35-37 | Recto- Vag | Cult | 246 | 13 | 5.3 | Moderate-risk |
| Khataie (64) | Tehran | 1998 | NA | Preg | 37 | Vag | Cult | 191 | 28 | 14.7 | Moderate-risk |
| Nasrollahi1 (65) | Sari | 2018 | < 25-30 > | Preg | 35-37 | Vag, Urine | Cult, PCR | 246 | 15 | 6.1 | Moderate-risk |
| Rostami (66) | Isfahan | 2015 | 29.35 ± 5.509 (mean) | Preg | 35-37 | Vag | Cult, PCR | 200 | 22 | 11 | Low-risk |
| Rect | Cult, PCR | 200 | 7 | 3.5 | Low-risk | ||||||
| Sahraee (67) | Rasht | 2017-2018 | NA | Preg | 35-37 | Vag | Cult, PCR | 245 | 19 | 7.8 | Moderate-risk |
| Rect | 245 | 24 | 9.8 | Moderate-risk | |||||||
| Abdollahi Fard (68) | Tabriz | 2006 | 22.96 ± 3.89 (mean) | Preg | 35-37 | Vag, Rect | Cult | 250 | 24 | 9.6 | Moderate-risk |
| Akbarian Rad (69) | Babol | 2012-2014 | 25.7 ± 5.55 (mean) | Preg | > 26 | Vag, Rect | Cult | 410 | 46 | 11.2 | Moderate-risk |
| Shahbazian (70) | Ahvaz | 2007 | NA | Preg | 35-37 | Vag, Rect | Cult | 250 | 33 | 13.2 | High-risk |
| Sarafrazi (71) | Kashan | 2000 | NA | Preg | 35-37 | Vag | Cult | 400 | 32 | 5.8 | High-risk |
Abbreviations: Cult, culture; GBS, Group B Streptococcus; NA, not available; Preg, pregnant; Rect, rectal; Rect-Vag, rectovaginal; Vag, vaginal.
3.2. Prevalence of Group B Streptococcus in Vaginal and Rectovaginal Swabs of Pregnant Women
| Sample | Number of Studies | Prevalence | 95% CI | Heterogeneity | P Value | ||
|---|---|---|---|---|---|---|---|
| Q- Statistic | I-Squared (%) | P Value | |||||
| Experiment date | |||||||
| < 2000 | 2 | 15.8 | 0.122-0.194 | 0.40 | 0.0 | 0.528 | < 0.001 |
| 2000 - 2009 | 12 | 11.8 | 0.076-0.160 | 339.12 | 96.8 | 0.000 | |
| ≥ 2010 | 20 | 13.4 | 0.096-0.172 | 454.24 | 95.6 | 0.000 | |
| City | < 0.001 | ||||||
| Kerman | 2 | 8.7 | 0.066-0.108 | 0.76 | 0.0 | 0.384 | |
| Yazd | 1 | 16.5 | 0.126-0.204 | 0.00 | |||
| Sanandaj | 1 | 61.5 | 0.548-0.682 | 0.00 | |||
| Mashhad | 3 | 6.4 | -0.003-0.131 | 13.25 | 84.9 | 0.001 | |
| Ardabil | 2 | 4.1 | 0.023-0.059 | 0.84 | 0.0 | 0.359 | |
| Tehran | 4 | 14.1 | 0.053-0.230 | 68.97 | 95.7 | 0.000 | |
| Ahvaz | 1 | 27.7 | 0.203-0.352 | 0.00 | |||
| Arak | 2 | 13.4 | 0.096-0.173 | 1.80 | 44.4 | 0.180 | |
| Kermanshah | 1 | 5 | 0.003-0.097 | 0.00 | |||
| Amol | 1 | 4 | -0.003-0.083 | 0.00 | |||
| Khorramabad | 1 | 14 | 0.071-0.209 | 0.00 | |||
| Isfahan | 2 | 23.1 | 0.082-0.381 | 38.77 | 94.8 | 0.000 | |
| Jahrom | 1 | 16.4 | 0.128-0.200 | 0.00 | |||
| Hamadan | 3 | 13.8 | 0.012-0.264 | 69.17 | 97.1 | 0.000 | |
| Ilam | 1 | 4.4 | -0.003-0.092 | 0.00 | |||
| Tabriz | 1 | 1.8 | 0.009-0.026 | 0.00 | |||
| Bushehr | 1 | 9.5 | 0.060-0.129 | 0.00 | |||
| Kashan | 2 | 8.6 | 0.067-0.106 | 0.48 | 0.0 | 0.487 | |
| Shahrekord | 1 | 17.6 | 0.146-0.206 | 0.00 | |||
| Rasht | 2 | 10.7 | 0.037-0.177 | 3.26 | 69.3 | 0.071 | |
| Babol | 1 | 7.8 | 0.051-0.104 | 0.00 | |||
| Quality assessment | < 0.001 | ||||||
| Low-risk | 8 | 13.7 | 0.090-0.184 | 124.62 | 93.6 | 0.000 | |
| Moderate-risk | 24 | 12.8 | 0.093-0.163 | 729.01 | 96.8 | 0.000 | |
| High-risk | 2 | 10.7 | 0.040-0.174 | 3.28 | 69.5 | 0.000 | |
| Overall | 34 | 12.9 | 0.103-0.155 | 865.91 | 96.1 | 0.000 | < 0.001 |
| Sample | Number of Studies | Prevalence | 95% CI | Heterogeneity | P Value | ||
|---|---|---|---|---|---|---|---|
| Q- Statistic | I-Squared (%) | P Value | |||||
| Experiment date | < 0.001 | ||||||
| < 2000 | 0 | - | - | - | |||
| 2000 - 2009 | 10 | 11.3 | 0.087-0.139 | 49.39 | 81.8 | 0.000 | |
| ≥ 2010 | 15 | 8.7 | 0.056-0.117 | 286.00 | 95.1 | 0.000 | |
| City | < 0.001 | ||||||
| Yazd | 2 | 16 | 0.092-0.228 | 4.36 | 77.1 | 0.037 | |
| Mashhad | 1 | 6 | 0.026-0.094 | 0.00 | . | . | |
| Ardabil | 3 | 10.7 | 0.052-0.162 | 21.40 | 90.7 | 0.000 | |
| Tehran | 7 | 9.9 | 0.041-0.156 | 132.41 | 95.5 | 0.793 | |
| Ahvaz | 1 | 13.2 | 0.090-0.174 | 0.00 | . | 0.000 | |
| Arak | 1 | 5.2 | 0.025-0.080 | 0.00 | . | . | |
| Amol | 1 | 3 | -0.010-0.070 | 0.00 | . | . | |
| Birjand | 1 | 5.2 | 0.032-0.072 | 0.00 | . | . | |
| Khorramabad | 1 | 17 | 0.096-0.244 | 0.00 | . | . | |
| Shiraz | 2 | 11.2 | 0.067-0.157 | 4.77 | 79.0 | 0.029 | |
| Isfahan | 1 | 18.2 | 0.124-0.241 | 0.00 | . | . | |
| Jahrom | 1 | 1.7 | 0.004-0.031 | 0.00 | . | . | |
| Tabriz | 1 | 9.6 | 0.059-0.133 | 0.00 | . | . | |
| Babol | 2 | 6.8 | -0.018-0.153 | 24.23 | 95.9 | 0.000 | |
| Quality assessment | < 0.001 | ||||||
| Low-risk | 6 | 12.2 | 0.049-0.195 | 281.57 | 98.2 | 0.000 | |
| Moderate-risk | 16 | 8.1 | 0.065-0.097 | 67.98 | 77.9 | 0.000 | |
| High-risk | 3 | 13 | 0.076-0.183 | 7.01 | 71.5 | 0.000 | |
| Overall | 25 | 9.7 | 0.075-0.120 | 373.41 | 93.6 | 0.000 | < 0.001 |

