Group B Streptococcus and HIV infection in pregnant women, Malawi, 2008-2010

Systematic review and meta-analysis of seroprevalence of human immunodeficiency virus serological markers among pregnant women in Africa, 1984-2020

BACKGROUND

Human immunodeficiency virus (HIV) is a major public health concern, particularly in Africa where HIV rates remain substantial. Pregnant women are at an increased risk of acquiring HIV, which has a significant impact on both maternal and child health.

AIM

To review summarizes HIV seroprevalence among pregnant women in Africa. It also identifies regional and clinical characteristics that contribute to study-specific estimates variation.

METHODS

The study included pregnant women from any African country or region, irrespective of their symptoms, and any study design conducted in any setting. Using electronic literature searches, articles published until February 2023 were reviewed. The quality of the included studies was evaluated. The DerSimonian and Laird random-effects model was applied to determine HIV pooled seroprevalence among pregnant women in Africa. Subgroup and sensitivity analyses were conducted to identify potential sources of heterogeneity. Heterogeneity was assessed with Cochran's Q test and I2 statistics, and publication bias was assessed with Egger's test.

RESULTS

A total of 248 studies conducted between 1984 and 2020 were included in the quantitative synthesis (meta-analysis). Out of the total studies, 146 (58.9%) had a low risk of bias and 102 (41.1%) had a moderate risk of bias. No HIV-positive pregnant women died in the included studies. The overall HIV seroprevalence in pregnant women was estimated to be 9.3% [95% confidence interval (CI): 8.3-10.3]. The subgroup analysis showed statistically significant heterogeneity across subgroups (P < 0.001), with the highest seroprevalence observed in Southern Africa (29.4%, 95%CI: 26.5-32.4) and the lowest seroprevalence observed in Northern Africa (0.7%, 95%CI: 0.3-1.3).

CONCLUSION

The review found that HIV seroprevalence among pregnant women in African countries remains significant, particularly in Southern African countries. This review can inform the development of targeted public health interventions to address high HIV seroprevalence in pregnant women in African countries.

Interspecies Interactions within the Host: the Social Network of Group B Streptococcus

Group B Streptococcus (GBS) is a pervasive neonatal pathogen accounting for a combined half a million deaths and stillbirths annually. The most common source of fetal or neonatal GBS exposure is the maternal microbiota. GBS asymptomatically colonizes the gastrointestinal and vaginal mucosa of 1 in 5 individuals globally, although its precise role in these niches is not well understood. To prevent vertical transmission, broad-spectrum antibiotics are administered to GBS-positive mothers during labor in many countries. Although antibiotics have significantly reduced GBS early-onset neonatal disease, there are several unintended consequences, including an altered neonatal microbiota and increased risk for other microbial infections. Additionally, the incidence of late-onset GBS neonatal disease remains unaffected and has sparked an emerging hypothesis that GBS-microbe interactions in developing neonatal gut microbiota may be directly involved in this disease process. This review summarizes our current understanding of GBS interactions with other resident microbes at the mucosal surface from multiple angles, including clinical association studies, agriculture and aquaculture observations, and experimental animal model systems. We also include a comprehensive review of in vitro findings of GBS interactions with other bacterial and fungal microbes, both commensal and pathogenic, along with newly established animal models of GBS vaginal colonization and in utero or neonatal infection. Finally, we provide a perspective on emerging areas of research and current strategies to design microbe-targeting prebiotic or probiotic therapeutic intervention strategies to prevent GBS disease in vulnerable populations.

Prevalence of Group B Streptococcus maternal colonization, serotype distribution, and antimicrobial resistance in Sub-Saharan Africa: A systematic review and meta-analysis

OBJECTIVE

Group B Streptococcus (GBS)-associated maternal, perinatal, and neonatal mortality and morbidity disproportionately affects Sub-Saharan Africa (SSA). This systematic review and meta-analysis aimed to address the estimated prevalence, antimicrobial susceptibility, and serotype distribution of GBS isolates in SSA.

METHODS

This study was done according to PRISMA guidelines. MEDLINE/PubMed, CINAHL (EBSCO), Embase, SCOPUS, Web of Sciences databases, and Google Scholar were used to retrieve both published and unpublished articles. STATA software version 17 was used for data analysis. Forest plots using the random-effect model were used to present the findings. Heterogeneity was assessed using Cochrane chi-square (I²) statistics, while the Egger intercept was used to assess publication bias.

RESULTS

Fifty-eight studies that fulfilled the eligibility criteria were included for meta-analysis. The pooled prevalence of maternal rectovaginal colonization and vertical transmission of GBS were 16.06, 95% CI [13.94, 18.30] and 43.31%, 95% CI [30.75, 56.32], respectively. The highest pooled proportion of antibiotic resistance to GBS was observed in gentamicin (45.58%, 95% CI [4.12%, 91.23]), followed by erythromycin, (25.11%, 95% CI [16.70, 34.49]). The lowest antibiotic resistance was observed in vancomycin (3.84%, 95% CI [0.48, 9.22]). Our findings indicate that serotypes Ia/Ib/II/ III/and V cover almost 88.6% of serotypes in SSA.

CONCLUSIONS

The estimated high prevalence and resistance to different antibiotic classes observed in GBS isolates from SSA suggests the need for implementation of effective intervention efforts.

Group B Streptococcus vaginal colonization in pregnant women living with HIV infection: prevalence and antibiotic susceptibility at HIV referral centers in Lagos, Nigeria

OBJECTIVES

Group B Streptococcus (GBS) colonization of the genital tract is often asymptomatic yet associated with increased risks of maternal and neonatal morbidity especially amongst women living with HIV infection. The objectives of this study were to determine the prevalence of GBS colonization of the genital tract in women living with HIV infection and antibiotic susceptibility of GBS in the genital tract.

METHOD

This cross-sectional study recruited 244 pregnant women (122 women living with HIV infection and 122 HIV-uninfected women) between 35 and 37 weeks of gestation. GBS colonization was determined by collecting lower vaginal and anal swabs at recruitment. Swabs were cultured in Todd Hewitt's broth and confirmed by Christie, Atkins, and Munch-Peterson (CAMP) test. Most recent CD4 count and viral load estimates were retrieved from the women's records. Maternal and neonatal outcomes and antibiotic susceptibility were assessed. Statistical analysis was performed at 95% confidence interval at a statistical significance of p < .005.

RESULTS

The prevalence of GBS colonization of the genital tract in all participants was 3.3%; GBS was isolated in 4 (3.3%) of 122 pregnant women living with HIV. No woman with a GBS-colonized genital tract developed puerperal sepsis and no neonatal infection occurred in neonates born to GBS-positive women, irrespective of HIV infection status. In women living with HIV, GBS isolate was resistant to Ampicillin (100%), Ceftriaxone (100%), Vancomycin (100%), yet partially sensitive to Ciprofloxacin (50%).

CONCLUSION

Pregnant women living with HIV do not have an increased risk of genital GBS colonization. Vaginal GBS colonization was not associated with an adverse perinatal outcome. Antibiotic use for GBS colonization should be based on sensitivity pattern and not empiric.

Prevalence and molecular characterization of group B streptococcus in pregnant women from hospitals in Ohangwena and Oshikoto regions of Namibia

Background

The main purpose of this study was to investigate the prevalence rate, antimicrobial susceptibility patterns and molecular characteristics of Streptococcus agalactiae isolated from pregnant women at 35 weeks of gestation and above, who attended antenatal screening at selected hospitals in Ohangwena and Oshikoto regions of Namibia.

Results

Out of 210 women screened for Group B Streptococcus (GBS), 12 (5.7%) were colonised of which 25.0% were colonised rectovaginally, 58.0% vaginally and 17.0% rectally. No significant association was reported between GBS colonisation and maternal age, geographic location, marital status, education, employment, parity, still births and miscarriages (P values > 0.05). Antimicrobial susceptibility was reported at 100% for ampicillin, penicillin & ceftriaxone which are commonly used for empiric treatment of infection with GBS. Resistance to tetracycline was reported at 100%. Tetracycline resistance gene tet(M) was present in 88.9% of the isolates only and none of the isolates presented with tet(O). Polysaccharide capsular type Ia was found in 9(50%) and Ib was found in 1(5.5%) of the total isolates. The remaining isolates were not typeable using PCR.

Conclusion

Streptococcus agalactiae’s positive rate was 5.7% among the pregnant women examined. Socio-demographic and obstetric factors had no influence on GBS colonisation (P values > 0.05). No resistance was reported to ampicillin, penicillin and ceftriaxone. No sensitivity was reported to tetracycline. Fifty percent of the isolates were capsular type Ia, 5.5% were type Ib and 44.4% were not typeable using PCR. The study provides crucial information for informing policy in screening of GBS in pregnant women.

Group B Streptococcus colonization rate and serotype distribution among pregnant women and their newborns at Adama Hospital Medical College, Ethiopia

Rectovaginal area of pregnant women can be colonized transiently with group B Streptococcus (GBS) without causing disease. The bacteria can be transmitted to the newborn before and during birth and cause early-onset neonatal disease. In this study, we aimed to determine the GBS colonization rate among pregnant women before delivery and their newborns and serotypes distribution of GBS. Two hundred-eighty pregnant women along with their newborns were screened for GBS colonization from June 2014 to October 2014 at Adama Hospital Medical College. Rectovaginal swabs from pregnant women before delivery and specimen from nasal area, external ear, umbilical cord and throat of newborns were collected and cultured. The serotyping of GBS was performed by using serotype-specific antisera. To collect sociodemographic and clinical data we employed a structured questionnaire. GBS colonization among pregnant women and their newborns were 13.2% 95% CI (8.9-17.5) and 7.4% 95% CI (4.6-10.6). Out of 37 GBS strains recovered from pregnant women, the prevalent serotypes were Ia 6(16.2%), Ib 8(21.6%), II 10(27%), III 3(8.1%), and V 8(21.6%). Out of 21 GBS strains recovered from newborns, prevalent serotypes were Ia 3(14.3%), Ib 6(28.6%), II 6(28.6%), III 4(19%), and V 1(4.8%). This study indicated the existence of primary risk factors for neonatal disease in Adama area. Serotype II was the common serotype detected in this study which is followed by serotype Ib, Ia, and V. As colonizing GBS serotypes could cause invasive disease among newborns, vaccine formulation which includes serotype II, Ia, V, Ib, and III can prevent of invasive disease caused by GBS in the study area.

Group B Streptococcus serotypes Ia and V induce differential vaginal immune responses that may contribute to long term colonization of the female reproductive tract

PROBLEM

Group B Streptococcus (GBS) is a common colonizer of the female genital tract at the time of pregnancy and has been associated with severe neonatal infections. Despite trials for GBS vaccines already being underway, the factors influencing vaginal GBS colonization and clearance are currently poorly understood.

METHOD OF STUDY

Within this study, we investigated the host immune responses to GBS infections in mice that affect GBS vaginal colonization and clearance. Cervicovaginal swabs were used to measure vaginal GBS persistence, and vaginal cytokine responses were measured using the BioPlex^® system. Lymphocytes isolated from spleens were stimulated with UV-killed GBS to examine systemic cellular responses. Additional in vitro cellular experiments using human vaginal epithelial cells were also performed, examining the effect pregnancy level hormones had on GBS adhesion, invasion, and cytokine responses.

RESULTS

We observed significant differences in the ability of GBS serotype V infections to persist, compared with GBS serotype Ia vaginal infections. Vaginal cytokine response examination identified temporal changes in cytokine production (IL10, IFNγ, IL6, IL1β, and TNFα) in relation to GBS serotype and clearance or colonization. Lymphocyte proliferation assays also revealed robust cellular immune responses to GBS vaginal infections irrespective of clearance or colonization. In vitro human cellular analyses also identified that vaginal epithelial cell line cytokine production was suppressed in the presence of hormones despite no alteration in adhesion/invasion.

CONCLUSION

Here, we establish previously unknown, serotype specific, temporal immune responses which may be associated with vaginal GBS colonization or clearance in the female genital tract.

Streptococcus agalactiae maternal colonization, antibiotic resistance and serotype profiles in Africa: a meta-analysis

Background

Maternal rectovaginal colonization with Streptococcus agalactiae (Group B Streptococcus or GBS) is the most common route for the GBS disease in the perinatal period. The knowledge of maternal colonization, antibiotic resistance and serotype profiles is substantially needed to formulate the broad vaccine. However, it has not been estimated in Africa. This meta-analysis was aimed to determine the pooled prevalence of colonization, antibiotic resistance and serotype profiles of GBS reported in Africa.

Methods

Potentially relevant studies from 1989 to 31th January, 2019 were retrieved from the Medline/PubMed, EMBASE, HINARI online databases, periodicals and by requesting authors. Unpublished studies retrieved from grey literature through Google and Google Scholar. Pooled estimates were calculated using the random effect model. Subgroup analysis was done to investigate the burden of colonization across sub-regions, sampling site and countries. Summary estimates were presented using words, Forest plots and Tables. Heterogeneity was assessed using the I² statistic.

Results

Eighty-three articles were assessed, of which 57 studies conducted in five sub-regions with 21 countries (22,206 pregnant women) met pre-specified inclusion criteria. The overall estimate of recto-vaginal colonization was 19.3% (95% CI 16.9, 21.7). The highest estimate was observed in Southern Africa, 23.8% (95% CI 18.7, 28.9), followed by Northern Africa, 22.7% (95% CI 18.2, 27.2) while the lowest was driven from the Eastern Africa, 15.4% (95% CI 12.1, 18.7). Considerable heterogeneity across and within regions, sampling site, screening methods and countries (I² > 75%); and the publication bias were observed (p = 0.031). GBS showed the highest resistance to tetracycline. Resistance to penicillin, amoxicillin, chloramphenicol, ampicillin, ceftriaxone, ciprofloxacin, erythromycin, vancomycin and clindamycin also observed. The V, III, Ia, Ib, and II serotypes altogether were accounted 91.8% in the African studies.

Conclusions

The pooled estimate of the maternal colonization with GBS was 19.3% which is equivalent with other many primary and review reports worldwide. The most antibiotic resistance estimate was recorded in the tetracycline followed by penicillin. Five serotypes were the most prevalent in Africa and more data on the antibiotic résistance and serotype distribution patterns are needed from developing countries to devise the effective preventive measures. In addition, the antibiotic susceptibility test methods used in the Africa shall be assessed for its quality.

Trial registration Prospero Registration Number CRD42018094525

Maternal immunisation to improve the health of HIV-exposed infants

HIV-exposed but uninfected (HEU) infants are at an increased risk of many infectious diseases that can contribute to the high mortality seen among HEU children. Maternal immunisation could be a promising strategy to reduce infections in HEU infants. However, very little research has explored the effect of HIV on the immunogenicity and effectiveness of vaccines given during pregnancy. We review the available evidence on maternal immunisation among women living with HIV (WLWH) for all vaccines recommended, considered, or being investigated for routine or risk-based use during pregnancy. Of the 11 vaccines included, only three have been investigated in WLWH. Available evidence suggests that maternal HIV infection limits the immunogenicity of several vaccines, leaving HEU infants more susceptible to infection during their first few months of life. Whether maternal immunisation reduces the infectious morbidity and mortality associated with infectious diseases in HEU children remains unknown. We conclude the Review by identifying future research priorities.

Prevalence, Risk Factors, and Serotype Distribution of Group B Streptococcus Colonization in HIV-Infected Pregnant Women Living in Belgium: A Prospective Cohort Study

Background

Group B streptococcus (GBS) infection is a leading cause of severe neonatal infection. Maternal GBS carriage during pregnancy is the main risk factor for both early-onset and late-onset GBS disease. High incidence of GBS infection has been reported in HIV-exposed but -uninfected infants (HEU). We aimed to determine the prevalence, characteristics, and risk factors for GBS colonization in HIV-infected and HIV-uninfected pregnant women living in Belgium.

Methods

Between January 1, 2011, and December 31, 2013, HIV-infected (n = 125) and -uninfected (n = 120) pregnant women had recto-vaginal swabs at 35–37 weeks of gestation and at delivery for GBS detection. Demographic, obstetrical, and HIV infection–related data were prospectively collected. GBS capsular serotyping was performed on a limited number of samples (33 from HIV-infected and 16 from HIV-uninfected pregnant women).

Results

There was no significant difference in the GBS colonization rate between HIV-infected and -uninfected pregnant women (29.6% vs 24.2%, respectively). HIV-infected women were more frequently colonized by serotype III (36.4% vs 12.5%), and the majority of serotype III strains belonged to the hypervirulent clone ST-17. Exclusively trivalent vaccine serotypes (Ia, Ib, and III) were found in 57.6% and 75% of HIV-infected and -uninfected women, respectively, whereas the hexavalent vaccine serotypes (Ia, Ib, II, III, IV, and V) were found in 97% and 100%, respectively.

Conclusions

HIV-infected and -uninfected pregnant women living in Belgium have a similar GBS colonization rate. A trend to a higher colonization rate with serotype III was found in HIV-infected women, and those serotype III strains belong predominantly to the hypervirulent clone ST17.

Maternal Carriage of Group B Streptococcus and Escherichia coli in a District Hospital in Mozambique

BACKGROUND

In low-income countries, data on prevalence and effects of group B Streptococcus (GBS) and Escherichia coli (E. coli) colonization among pregnant women are scarce, but necessary to formulate prevention strategies. We assessed prevalence of GBS and E. coli colonization and factors associated among pregnant women, its effect in newborns and acceptability regarding the utilized sampling methods in a semirural Mozambican hospital.

METHODS

Pregnant women were recruited from June 2014 to January 2015, during routine antenatal clinics at gestational age ≥ 34 weeks (n = 200); or upon delivery (n = 120). Maternal risk factors were collected. Vaginal and vagino-rectal samples for GBS and E. coli determination were obtained and characterized in terms of antimicrobial resistance and serotype. Anti-GBS antibodies were also determined. Neonatal follow-up was performed in the first 3 months after birth. Semistructured interviews were performed to investigate acceptability of sample collection methods.

RESULTS

In total, 21.3% of women recruited were GBS carriers, while 16.3% were positive for E. coli. Prevalence of HIV was 36.6%. No association was found between being colonized by GBS and E. coli and maternal risk factors. GBS isolates were fully susceptible to penicillin and ampicillin. Serotypes V (32.4%), Ia (14.7%) and III (10.3%) were the most commonly found and 69.2% of the women tested had immunoglobuline G antibodies against GBS. E. coli isolates showed resistance to ampicillin in 28.9% and trimethoprim/sulfamethoxazole in 61.3% of the cases.

CONCLUSION

Prevalence of GBS and/or E. coli colonization among pregnant women is high in this semirural community and comparable with those reported in similar settings. Four serotypes accounted for nearly 70% of all isolates of GBS. Population-based data on infant GBS infections would enable the design of prevention strategies for GBS disease in Mozambique.

Risk factors for neonatal group B streptococcus vertical transmission: a prospective cohort study of 1815 mother-baby pairs

BACKGROUND

The potential factors associated with group B streptococcus (GBS) vertical transmission have not been studied in detail.

STUDY DESIGN

A prospective cohort study was conducted to recruit 1815 mother-neonate pairs for GBS analysis. Pearson's chi-squared tests and generalized linear models were used to explore the risk factors for neonatal GBS colonization.

RESULTS

The rate of GBS vertical transmission was 14.1%. GBS colonization in all neonates was significantly associated with maternal GBS colonization, mode of delivery, episiotomy, number of prenatal vaginal exams, parity, and hypertension. For neonates born to GBS-positive mothers, GBS vertical transmission was associated with the mode of delivery, episiotomy, and sexually transmitted diseases. For neonates born to GBS-negative mothers, neonatal GBS colonization was associated with the number of prenatal vaginal exams, parity, and hypertension.

CONCLUSION

These findings suggest the need for prenatal GBS screening for pregnant women and intrapartum antimicrobial prophylaxis for GBS-colonized women.

Group B streptococci vaginal colonization and drug susceptibility pattern among pregnant women attending in selected public antenatal care centers in Addis Ababa, Ethiopia

Background

Group B Streptococcus (GBS) is the leading cause of septicemia, meningitis, and pneumonia in neonates. Maternal colonization with GBS is the principal risk factor for early-onset disease in infants. Group B Streptococcus is now an important cause of maternal and neonatal morbidity and mortality in many parts of the world. In Ethiopia, few studies have been done on GBS colonization among pregnant women. The aim of this study was to determine the prevalence of GBS colonization, antimicrobial susceptibility patterns and assess risk factors among pregnant women.

Methods

A prospective cross-sectional study was conducted from May to August 2014 at selected public antenatal care (ANC) centers in Addis Ababa, Ethiopia. Clinical and socio-demographical data were collected using structured questionnaire after obtaining written informed consent. A total of 281 lower vaginal swabs were collected and inoculated into 1 ml Todd Hewitt Broth supplemented with gentamicin and nalidixic acid to prevent the growth of contaminants. After overnight incubation, all broths were subcultured on 5% sheep blood agar for isolation of GBS. Antimicrobial susceptibility testing was performed according to the criteria of the Clinical and Laboratory Standard Institute (CLSI) guidelines 2013 by disk diffusion method. Data were entered and analysed using SPSS version 20.0 software. Chi-square test and binary logistic regression analysis were used. P-value < 0.05 was considered statistically significant.

Results

The overall prevalence of GBS colonization among pregnant women was 14.6% (41/281). Group B Streptococcus colonization was significantly associated with health institutions (P < 0.05). All GBS isolates were susceptible to chloramphenicol. Resistance to tetracycline, cefotaxime, clindamycin, penicillin, vancomycin, ampicillin and erythromycin was 90.2%, 34.1, 26.8%, 19.5, 17%, 14.6 and 7.5% respectively. Multidrug resistance (MDR) (≥ 2 drugs) was detected in 43.9% (18/41) of the isolates.

Conclusion

There was a high frequency of GBS colonization (14.6%) and resistance to the commonly used antibiotics which suggests the importance of the screening of GBS colonization in pregnant women at 35–37 weeks of gestation and testing their antimicrobial susceptibilities in order to provide antibiotic prophylaxis and minimize newborn infection and co-morbidity.

Role of HIV exposure and infection in relation to neonatal GBS disease and rectovaginal GBS carriage: a systematic review and meta-analysis

Streptococcus agalactiae (GBS) is the leading cause worldwide of neonatal sepsis. We sought to assess to which extent HIV exposure of neonates is associated with GBS neonatal disease. Furthermore, we assessed to which extent HIV infection in women is associated with maternal rectovaginal GBS carriage, the single most important risk factor for GBS neonatal disease. We searched Pubmed, Embase, and Web of Science for studies assessing the association between neonatal GBS disease and HIV-status of the mother and studies that assessed the association between rectovaginal GBS colonization and HIV status in women. HIV-exposed uninfected neonates were more than twice as likely to have neonatal GBS disease compared to unexposed neonates. HIV-exposed neonates were not at increased risk for early-onset neonatal disease, but were 4.43 times more likely to have late-onset neonatal GBS disease. There was no significant association between HIV infection status and rectovaginal GBS carriage. Public health interventions preventing neonatal GBS disease are urgently needed for the increasing group of HIV-exposed neonates. A framework integrating and explaining our findings highlights opportunities for the clinical practice and global health policy to prevent disease. Well-designed studies should clarify the relation between HIV-status and GBS carriage.

Bacterial communities found in placental tissues are associated with severe chorioamnionitis and adverse birth outcomes

Preterm birth is a major cause of neonatal mortality and morbidity worldwide. Bacterial infection and the subsequent inflammatory response are recognised as an important cause of preterm birth. It is hypothesised that these organisms ascend the cervical canal, colonise placental tissues, cause chorioamnionitis and in severe cases infect amniotic fluid and the foetus. However, the presence of bacteria within the intrauterine cavity does not always precede chorioamnionitis or preterm birth. Whereas previous studies observing the types of bacteria present have been limited in size and the specificity of a few predetermined organisms, in this study we characterised bacteria found in placental tissues from a cohort of 1391 women in rural Malawi using 16S ribosomal RNA gene sequencing. We found that specific bacteria found concurrently on placental tissues associate with chorioamnionitis and delivery of a smaller newborn. Severe chorioamnionitis was associated with a distinct difference in community members, a higher bacterial load and lower species richness. Furthermore, Sneathia sanguinengens and Peptostreptococcus anaerobius found in both matched participant vaginal and placental samples were associated with a lower newborn length-for-age Z-score. This is the largest study to date to examine the placental microbiome and its impact of birth outcomes. Our results provide data on the role of the vaginal microbiome as a source of placental infection as well as the possibility of therapeutic interventions against targeted organisms during pregnancy.

Group B streptococcus and respiratory syncytial virus immunisation during pregnancy: a landscape analysis

Group B streptococcus and respiratory syncytial virus are leading causes of infant morbidity and mortality worldwide. No licensed vaccines are available for either disease, but vaccines for both are under development. Severe respiratory syncytial virus disease can be prevented by passively administered antibody. The presence of maternal IgG antibody specific to respiratory syncytial virus is associated with reduced prevalence and severity of respiratory syncytial virus disease in the first few weeks of life, whereas maternal serotype-specific anticapsular antibody is associated with protection against both early-onset and late-onset group B streptococcus disease. Therefore, vaccination in pregnancy might protect infants against both diseases. This report describes what is known about immune protection against group B streptococcus and respiratory syncytial virus, identifies knowledge gaps regarding the immunobiology of both diseases, and aims to prioritise research directions in maternal immunisation.

Vaccination of HIV-infected pregnant women: implications for protection of their young infants

Background

The prevention of mother to child transmission of HIV has resulted in reduced burden of pediatric HIV-infection, but the prevalence of maternal HIV infection remains high in sub-Saharan African countries. HIV-exposed-uninfected infants have an increased risk of morbidity and mortality due to infectious diseases than HIV-unexposed infants, particularly during the first six months of life, which in part might be due to lower levels of pathogen-specific protective antibodies acquired transplacentally from their mothers. This could be mitigated by vaccinating pregnant women to boost antibody levels; although vaccine responses among HIV-infected pregnant women might differ compared to HIV-uninfected women. We reviewed studies that compared natural and vaccine-induced antibody levels to different epitopes between HIV-infected and HIV-uninfected pregnant women.

Findings

Most studies reported lower baseline/pre-vaccination antibody levels in HIV-infected pregnant women, which may not be reversed by antiretroviral therapy during pregnancy. There were only few studies on vaccination of HIV-infected pregnant women, mainly on influenza virus and group B Streptococcus (GBS) vaccines. Immunogenicity studies on influenza vaccines indicated that HIV-infected pregnant women had lower vaccine induced hemagglutination inhibition antibody titers and a decreased likelihood of seroconversion compared to HIV-uninfected women; and while higher CD4+ T-lymphocyte levels were associated with better immune responses to vaccination, HIV viral load was not associated with responses. Furthermore, infants born to influenza vaccinated HIV-infected pregnant women also had lower antibody levels and a lower proportion of HIV-exposed infants had titers above the putative correlate of protection compared to HIV-unexposed infants. The immunogenicity of a CRM₁₉₇-conjugated trivalent GBS vaccine was also lower in HIV-infected pregnant women compared to HIV-uninfected women, irrespective of CD4+ T-lymphocyte counts.

Conclusions

Poorer immunogenicity of vaccines reported in HIV-infected compared to HIV-uninfected pregnant women might compromise the potential benefits to their young infants. Alternate vaccination strategies, including vaccines with higher antigen concentration, adjuvanted vaccines or multiple doses schedules might be required in HIV-infected pregnant women to optimize antibody transferred to their fetuses.

Challenges in reducing group B Streptococcus disease in African settings

Group B Streptococcus (GBS) is a leading cause of neonatal sepsis and meningitis in high-income settings and is associated with high rates of neonatal mortality and morbidity. There is now increasing evidence to suggest that there is a high GBS disease burden in resource-limited countries, and it is therefore critically important to identify suitable and practical preventive strategies. In Europe and North America, intrapartum antibiotic prophylaxis (IAP) has led to a dramatic reduction of early-onset GBS disease. However, the methods for identifying pregnant women who should receive IAP and how to reduce late-onset GBS disease are not without controversy and are challenging for most sub-Saharan African countries. GBS vaccines are approaching phase III trials but are still under development. This review aims to explore the current evidence related to strategies for reducing invasive GBS disease in an African setting, the development of a GBS vaccine and whether preventative measures against GBS disease can be practically implemented.

Increased Risk of Group B Streptococcus Invasive Infection in HIV-Exposed but Uninfected Infants: A Review of the Evidence and Possible Mechanisms

Group B Streptococcus (GBS) is a major cause of neonatal sepsis and mortality worldwide. Studies from both developed and developing countries have shown that HIV-exposed but uninfected (HEU) infants are at increased risk of infectious morbidity, as compared to HIV-unexposed uninfected infants (HUU). A higher susceptibility to GBS infections has been reported in HEU infants, particularly late-onset diseases and more severe manifestations of GBS diseases. We review here the possible explanations for increased susceptibility to GBS infection. Maternal GBS colonization during pregnancy is a major risk factor for early-onset GBS invasive disease, but colonization rates are not higher in HIV-infected compared to HIV-uninfected pregnant women, while selective colonization with more virulent strains in HIV-infected women is suggested in some studies. Lower serotype-specific GBS maternal antibody transfer and quantitative and qualitative defects of innate immune responses in HEU infants may play a role in the increased risk of GBS invasive disease. The impact of maternal antiretroviral treatment and its consequences on immune activation in HEU newborns are important to study. Maternal immunization presents a promising intervention to reduce GBS burden in the growing HEU population.

Prevalence of maternal colonisation with group B streptococcus: a systematic review and meta-analysis

BACKGROUND

The most important risk factor for early-onset (babies younger than 7 days) invasive group B streptococcal disease is rectovaginal colonisation of the mother at delivery. We aimed to assess whether differences in colonisation drive regional differences in the incidence of early-onset invasive disease.

METHODS

We did a systematic review of maternal group B streptococcus colonisation studies by searching MEDLINE, Embase, Pascal Biomed, WHOLIS, and African Index Medicus databases for studies published between January, 1997, and March 31, 2015, that reported the prevalence of group B streptococcus colonisation in pregnant women. We also reviewed reference lists of selected studies and contacted experts to identify additional studies. Prospective studies in which swabs were collected from pregnant women according to US Centers for Disease Control and Prevention guidelines that used selective culture methods were included in the analyses. We calculated mean prevalence estimates (with 95% CIs) of maternal colonisation across studies, by WHO region. We assessed heterogeneity using the I(2) statistic and the Cochran Q test.

FINDINGS

221 full-text articles were assessed, of which 78 studies that included 73 791 pregnant women across 37 countries met prespecified inclusion criteria. The estimated mean prevalence of rectovaginal group B streptococcus colonisation was 17·9% (95% CI 16·2-19·7) overall and was highest in Africa (22·4, 18·1-26·7) followed by the Americas (19·7, 16·7-22·7) and Europe (19·0, 16·1-22·0). Studies from southeast Asia had the lowest estimated mean prevalence (11·1%, 95% CI 6·8-15·3). Significant heterogeneity was noted across and within regions (all p≤0·005). Differences in the timing of specimen collection in pregnancy, selective culture methods, and study sample size did not explain the heterogeneity.

INTERPRETATION

The country and regional heterogeneity in maternal group B streptococcus colonisation is unlikely to completely explain geographical variation in early-onset invasive disease incidence. The contribution of sociodemographic, clinical risk factor, and population differences in natural immunity need further investigation to understand these regional differences in group B streptococcus maternal colonisation and early-onset disease.

FUNDING

None.

Disease Burden of Group B Streptococcus Among Infants in Sub-Saharan Africa: A Systematic Literature Review and Meta-analysis

BACKGROUND

Group B streptococcus (GBS) is a leading neonatal sepsis pathogen globally. Investment in GBS disease prevention, such as maternal vaccination, requires evidence of disease burden, particularly in high infant mortality regions like sub-Saharan Africa. We aimed to provide such evidence by conducting a systematic literature review and meta-analysis to estimate maternal colonization proportion, GBS disease incidence and GBS serotype distribution.

METHODS

MEDLINE, MEDLINE in process and Cochrane Library were searched for studies published during 1990-2014, pertaining to sub-Saharan Africa. Eligible studies were used to estimate the proportion of pregnant women colonized with GBS, early-onset GBS disease incidence, late-onset GBS disease incidence and respective serotype distributions. Random effects meta-analysis was conducted to estimate weighted means and confidence intervals (CIs).

RESULTS

We identified 17 studies of colonization, 9 of disease incidence, and 6 of serotype distribution meeting inclusion criteria. 21.8% (95% CI: 18.3, 25.5) of expectant women were colonized with GBS. The incidence of early-onset GBS disease was 1.3 per 1000 births (95% CI: 0.81, 1.9), that of late-onset GBS disease 0.73 per 1000 births (95% CI: 0.48, 1.0). The most common disease-causing serotype was 3, followed by 1a. Serotypes 1b, 2 and 5 were next most common in frequency.

CONCLUSION

Despite methodological factors leading to underestimation, GBS disease incidence appears high in sub-Saharan Africa. A small number of GBS serotypes cause almost all disease. GBS disease burden in sub-Saharan Africa suggests that safe, effective and affordable GBS disease prevention is needed.

Maternal colonization with Streptococcus agalactiae and associated stillbirth and neonatal disease in coastal Kenya

Streptococcus agalactiae (group B streptococcus, GBS) causes neonatal disease and stillbirth, but its burden in sub-Saharan Africa is uncertain. We assessed maternal recto-vaginal GBS colonization (7,967 women), stillbirth and neonatal disease. Whole-genome sequencing was used to determine serotypes, sequence types and phylogeny. We found low maternal GBS colonization prevalence (934/7,967, 12%), but comparatively high incidence of GBS-associated stillbirth and early onset neonatal disease (EOD) in hospital (0.91 (0.25-2.3)/1,000 births and 0.76 (0.25-1.77)/1,000 live births, respectively). However, using a population denominator, EOD incidence was considerably reduced (0.13 (0.07-0.21)/1,000 live births). Treated cases of EOD had very high case fatality (17/36, 47%), especially within 24 h of birth, making under-ascertainment of community-born cases highly likely, both here and in similar facility-based studies. Maternal GBS colonization was less common in women with low socio-economic status, HIV infection and undernutrition, but when GBS-colonized, they were more probably colonized by the most virulent clone, CC17. CC17 accounted for 267/915 (29%) of maternal colonizing (265/267 (99%) serotype III; 2/267 (0.7%) serotype IV) and 51/73 (70%) of neonatal disease cases (all serotype III). Trivalent (Ia/II/III) and pentavalent (Ia/Ib/II/III/V) vaccines would cover 71/73 (97%) and 72/73 (99%) of disease-causing serotypes, respectively. Serotype IV should be considered for inclusion, with evidence of capsular switching in CC17 strains.

HIV-exposed, uninfected infants: new global challenges in the era of paediatric HIV elimination

The number of infants infected with HIV is declining with the rise in interventions for the elimination of paediatric HIV infection, but the number of uninfected infants exposed to HIV through their HIV-infected mothers is increasing. Interest in the health outcomes of HIV-exposed, uninfected infants has grown in the past decade, with several studies suggesting that these infants have increased mortality rates, increased infectious morbidity, and impaired growth compared with HIV-unexposed infants. However, heterogeneous results might reflect the inherent challenges in studies of HIV-exposed, uninfected infants, which need large populations with appropriate, contemporaneous comparison groups and repeated HIV testing throughout the period of breastfeeding. We review the effects of HIV exposure on mortality, morbidity, and growth, discuss the immunological abnormalities identified so far, and provide an overview of interventions that could be effective in this susceptible population. As the number of infants infected with HIV declines, the health needs of HIV-exposed, uninfected infants should be prioritised further, to ensure that post-2015 Sustainable Development Goals are achieved.

Group B streptococcus vaccination in pregnant women with or without HIV in Africa: a non-randomised phase 2, open-label, multicentre trial

Background

Neonates born to women infected with HIV are at increased risk for invasive group B streptococcus (GBS) disease. We aimed to compare safety and immunogenicity of trivalent glycoconjugate GBS vaccine in pregnant women with and without HIV in Malawi and South Africa.

Methods

In our non-randomised phase 2, open-label, multicentre study, we recruited pregnant women attending two antenatal clinics, one in Blantyre, Malawi, and one in Soweto, Johannesburg, South Africa. Participants were divided into three groups on the basis of their HIV infection status (no infection, infection and high CD4 cell count [>350 cells per μL], and infection and low CD4 cell count [>50 to ≤350 cells per μL]) and received a 5 μg dose of glycoconjugate GBS vaccine (serotypes Ia, Ib, and III, with CRM₁₉₇ [Novartis Vaccines, Siena, Italy]) intramuscularly at 24–35 weeks' gestation. GBS serotype-specific antibody concentrations were measured before vaccination (day 1), day 15, day 31, and at delivery, and in infants at birth and day 42 of life. The primary outcomes were safety in mothers and infants and the amount of placental transfer of GBS serotype-specific antibodies from mothers to their infants. All immunogenicity and safety analyses were done on the full analysis set, including participants who, or whose mother, correctly received the vaccine and who provided at least one valid assessable serum sample. This study is registered with ClinicalTrials.gov, number NCT01412801.

Findings

270 women and 266 infants were enrolled between Sept 26, 2011, and Dec 4, 2012 (90 women and 87 infants without HIV, 89 and 88 with HIV and high CD4 cell counts, and 91 and 91 with HIV and low CD4 cell counts, respectively). Seven women were lost to follow-up, six withdrew consent, one died, and two relocated. Eight infants died or were stillborn and two were lost to follow-up. Across serotypes, fold change in antibody concentrations were higher for the HIV-uninfected group than the HIV-infected groups. Transfer ratios were similar across all three groups (0·49–0·72; transfer ratio is infant geometric mean antibody concentration in blood collected within 72 h of birth divided by maternal geometric mean antibody concentration in blood collected at delivery); however, at birth, maternally derived serotype-specific antibody concentrations were lower for infants born to women infected with HIV (0·52–1·62 μg/mL) than for those born to women not infected with HIV (2·67–3·91 μg/mL). 151 (57%) of 265 women reported at least one solicited adverse reaction: 39 (45%) of 87 women with HIV and low CD4 cell counts, 52 (59%) of 88 women with HIV and high CD4 cell counts, and 60 (67%) of 90 women in the HIV-uninfected group. 49 (18%) of 269 women had at least one adverse event deemed possibly related to the vaccine (six [7%] in the HIV and low CD4 cell count group, 12 [13%] in the HIV and high CD4 cell count group, and 21 [23%] in the HIV-uninfected group), as did three (1%) of 266 neonates (zero, two [1%], and one [1%]); none of these events was regarded as serious.

Interpretation

The vaccine was less immunogenic in women infected with HIV than it was in those not infected, irrespective of CD4 cell count, resulting in lower levels of serotype-specific maternal antibody transferred to infants, which could reduce vaccine protection against invasive GBS disease. A validated assay and correlate of protection is needed to understand the potential protective value of this vaccine.

Funding

Novartis Vaccines and Diagnostics division (now part of the GlaxoSmithKline group of companies), Wellcome Trust UK, Medical Research Council: Respiratory and Meningeal Pathogens Research Unit.

A Multi-Country Cross-Sectional Study of Vaginal Carriage of Group B Streptococci (GBS) and Escherichia coli in Resource-Poor Settings: Prevalences and Risk Factors

BACKGROUND

One million neonates die each year in low- and middle-income countries because of neonatal sepsis; group B Streptococcus (GBS) and Escherichia coli are the leading causes. In sub-Saharan Africa, epidemiological data on vaginal GBS and E. coli carriage, a prerequisite for GBS and E. coli neonatal sepsis, respectively, are scarce but necessary to design and implement prevention strategies. Therefore, we assessed vaginal GBS and E. coli carriage rates and risk factors and the GBS serotype distribution in three sub-Saharan countries.

METHODS

A total of 430 women from Kenya, Rwanda and South Africa were studied cross-sectionally. Vaginal carriage of GBS and E. coli, and GBS serotype were assessed using molecular techniques. Risk factors for carriage were identified using multivariable logistic regression analysis.

RESULTS

Vaginal carriage rates in reference groups from Kenya and South Africa were 20.2% (95% CI, 13.7-28.7%) and 23.1% (95% CI, 16.2-31.9%), respectively for GBS; and 25.0% (95% CI, 17.8-33.9%) and 27.1% (95% CI, 19.6-36.2%), respectively for E. coli. GBS serotypes Ia (36.8%), V (26.3%) and III (14.0%) were most prevalent. Factors independently associated with GBS and E. coli carriage were Candida albicans, an intermediate vaginal microbiome, bacterial vaginosis, recent vaginal intercourse, vaginal washing, cervical ectopy and working as a sex worker. GBS and E. coli carriage were positively associated.

CONCLUSIONS

Reduced vaginal GBS carriage rates might be accomplished by advocating behavioral changes such as abstinence from sexual intercourse and by avoidance of vaginal washing during late pregnancy. It might be advisable to explore the inclusion of vaginal carriage of C. albicans, GBS, E. coli and of the presence of cervical ectopy in a risk- and/or screening-based administration of antibiotic prophylaxis. Current phase II GBS vaccines (a trivalent vaccine targeting serotypes Ia, Ib, and III, and a conjugate vaccine targeting serotype III) would not protect the majority of women against carriage in our study population.

Increased risk for group B Streptococcus sepsis in young infants exposed to HIV, Soweto, South Africa, 2004-2008(1)

Vaccination of pregnant women could prevent 2,105 invasive GBS cases and 278 deaths among infants annually.

Although group B Streptococcus (GBS) is a leading cause of severe invasive disease in young infants worldwide, epidemiologic data and knowledge about risk factors for the disease are lacking from low- to middle-income countries. To determine the epidemiology of invasive GBS disease among young infants in a setting with high maternal HIV infection, we conducted hospital-based surveillance during 2004–2008 in Soweto, South Africa. Overall GBS incidence was 2.72 cases/1,000 live births (1.50 and 1.22, respectively, among infants with early-onset disease [EOD] and late-onset [LOD] disease). Risk for EOD and LOD was higher for HIV-exposed than HIV-unexposed infants. GBS serotypes Ia and III accounted for 84.0% of cases, and 16.9% of infected infants died. We estimate that use of trivalent GBS vaccine (serotypes Ia, Ib, and III) could prevent 2,105 invasive GBS cases and 278 deaths annually among infants in South Africa; therefore, vaccination of all pregnant women in this country should be explored.

HIV-1 Is Associated With Lower Group B Streptococcus Capsular and Surface-Protein IgG Antibody Levels and Reduced Transplacental Antibody Transfer in Pregnant Women

BACKGROUND

Human immunodeficiency virus (HIV)-exposed infants are at increased risk of invasive Group B Streptococcus (GBS) disease; however, the reason for this increased susceptibility has not been characterized.

METHODS

We compared GBS capsular and surface-protein maternal immunoglobin G antibody concentrations and cord-maternal ratios between HIV-infected and HIV-uninfected mother-newborn dyads.

RESULTS

Median capsular antibody concentrations (µg/mL) were lower in HIV-infected than HIV-uninfected women for serotypes Ib (P = .033) and V (P = .040); and for pilus island (PI)-1 (P = .016), PI-2a (P = .015), PI-2b (P = .015), and fibrinogen-binding protein A (P < .001). For serotypes Ia and III, cord-maternal ratios were 37.4% (P < .001) and 32.5% (P = .027) lower in HIV-infected compared to HIV-uninfected mother-newborn dyads. The adjusted odds of having capsular antibody concentration ≥2 µg/mL when comparing HIV-infected to -uninfected women were 0.33 (95% confidence interval [CI], .15-.75) and 0.34 (95% CI, .12-1.00) for serotypes Ia and III, respectively. Antibody levels and cord-maternal ratios were independent of CD4(+) lymphocyte counts or HIV-1 viral load.

CONCLUSIONS

The lower GBS antibody concentrations and reduced transplacental antibody transfer in HIV-infected women, which likely contribute to their infants being at heightened susceptibility for invasive GBS disease, could possibly be mitigated by vaccination with a GBS conjugate vaccine currently under clinical development.

Anti-group B Streptococcus antibody in infants born to mothers with human immunodeficiency virus (HIV) infection

BACKGROUND

HIV-exposed uninfected infants have increased infection risk and mortality compared to HIV-unexposed infants. HIV-exposed infants may be at increased risk of invasive GBS disease due to reduced maternal antibody against GBS.

METHODS

We quantified antibodies that bind to the surface of whole Group B Streptococcus (GBS) of serotypes Ia, Ib, II, III and V using novel flow cytometry assays in South African HIV-infected and non-infected mothers and their uninfected infants. Antibody-mediated complement C3b/iC3b deposition onto GBS of these serotypes was also quantified by a novel flow cytometry assay.

RESULTS

Geometric mean concentration (GMC) of both surface-binding anti-GBS antibody and antibody-mediated complement deposition onto GBS were reduced in HIV-infected women (n=46) compared to HIV-uninfected women (n=58) for ST1a (surface-binding: 19.3 vs 29.3; p=0.003; complement deposition: 2.9 vs 5.3 SU/mL; p=0.003), STIb (24.9 vs 47.6; p=0.003; 2.6 vs 4.9 SU/mL; p=0.003), STII (19.8 vs 50.0; p=0.001; 3.1 vs 6.2 SU/mL; p=0.001), STIII (27.8 vs 60.1; p=0.001; 2.8 vs 5.3 SU/mL; p=0.001) and STV (121.9 vs 185.6 SU/mL; p<0.001) and in their infants for STIa (complement deposition 9.4 vs 27.0 SU/mL; p=0.02), STIb (13.4 vs 24.5 SU/mL; p=0.02), STII (14.6 vs 42.7 SU/mL; p=0.03), STIII (26.6 vs 62.7 SU/mL; p=0.03) and STV (90.4 vs 165.8 SU/mL; p=0.04). Median transplacental transfer of antibody from HIV-infected women to their infants was reduced compared to HIV-uninfected women for GBS serotypes II (0.42 [IQR 0.22-0.59] vs 1.0 SU/mL [0.42-1.66]; p<0.001), III (0.54 [0.31-1.03] vs 0.95 SU/mL [0.42-3.05], p=0.05) and V (0.51 [0.28-0.79] vs 0.75 SU/mL [0.26-2.9], p=0.04). The differences between infants remained significant at 16 weeks of age.

CONCLUSIONS

Maternal HIV infection was associated with lower anti-GBS surface binding antibody concentration and antibody-mediated C3b/iC3b deposition onto GBS bacteria of serotypes Ia, Ib, II, III and V. This may render these infants more susceptible to early and late onset GBS disease.

The microbial spectrum of neonatal sepsis in Uganda: recovery of culturable bacteria in mother-infant pairs

Neonatal sepsis in the developing world is incompletely characterized. We seek to characterize the microbial spectrum involved in sepsis and determine the role of maternal transmission by comparing organisms that can be cultured from septic newborn infants and their mothers. From 80 consecutive mother-infant pairs meeting clinical criteria for neonatal sepsis, we collected infant blood and spinal fluid, and maternal blood and vaginal specimens. Identifiable bacteria were recovered from the blood in 32.5% of infants, and from 2.5% of cerebrospinal fluid cultures, for a total of 35% recoverable putative causative agents. Bacteria recovered from vaginal specimens were not concordant with those recovered from infants. Similarly there was no concordance of bacteria recovered from blood and cerebrospinal fluid. We conclude that relying on traditional bacterial culture techniques does not adequately delineate the role of maternal versus environmental sources of neonatal sepsis in this setting. More sensitive molecular approaches will be needed to properly characterize the maternal and environmental microbial community involved in neonatal sepsis in such developing countries.

Institutional prevention policies and rates of Group B Streptococcus infection among HIV-infected pregnant women and their infants in Latin America

OBJECTIVE

To describe Group B Streptococcus (GBS) prevention policies at 12 Latin American sites participating in the NICHD (Eunice Kennedy Shriver National Institute of Child Health and Human Development) International Site Development Initiative (NISDI) Longitudinal Study in Latin American Countries (LILAC) and to determine rates of rectovaginal colonization and GBS-related disease among HIV-infected pregnant women and their infants.

METHODS

Site surveys were used to assess prevention policies and practices administered cross-sectionally during 2010. Data collected in NISDI from 2008 to 2010 regarding HIV-infected pregnant women were used to determine rates of colonization and GBS-related disease.

RESULTS

Of the 9 sites with a GBS prevention policy, 7 performed routine rectovaginal screening for GBS. Of the 401 women included in the NISDI study, 56.9% were at sites that screened. The GBS colonization rate was 8.3% (19/228 women; 95% confidence interval [CI], 5.1%-12.7%). Disease related to GBS occurred in 0.5% of the participants (2/401 women; 95% CI, 0.1%-1.8%); however, no GBS-related disease was reported among the 398 infants (95% CI, 0.0%-0.9%).

CONCLUSION

Improved efforts to implement prevention policies and continued surveillance for GBS are needed to understand the impact of GBS among HIV-infected pregnant women and their infants in Latin America.

Maternal HIV infection and vertical transmission of pathogenic bacteria

BACKGROUND

HIV-exposed newborns may be at higher risk of sepsis because of immune system aberrations, impaired maternal antibody transfer and altered exposure to pathogenic bacteria.

METHODS

We performed a secondary analysis of a study (clinicaltrials.gov, number NCT00136370) conducted between April 2004 and October 2007 in South Africa. We used propensity score matching to evaluate the association between maternal HIV infection and (1) vaginal colonization with bacterial pathogens; (2) vertical transmission of pathogens to the newborn; and (3) sepsis within 3 days of birth (EOS) or between 4-28 days of life (LOS).

RESULTS

Colonization with group B Streptococcus (17% vs 23%, P = .0002), Escherichia coli (47% vs 45%, P = .374), and Klebsiella pneumoniae (7% vs 10%, P = .008) differed modestly between HIV-infected and uninfected women, as did vertical transmission rates. Maternal HIV infection was not associated with increased risk of neonatal EOS or LOS, although culture-confirmed EOS was >3 times higher among HIV-exposed infants (P = .05). When compared with HIV-unexposed, neonates, HIV-exposed, uninfected neonates (HEU) had a lower risk of EOS (20.6 vs 33.7 per 1000 births; P = .046) and similar rate of LOS (5.8 vs 4.1; P = .563). HIV-infected newborns had a higher risk than HEU of EOS (134 vs 21.5; P < .0001) and LOS (26.8 vs 5.6; P = .042).

CONCLUSIONS

Maternal HIV infection was not associated with increased risk of maternal bacterial colonization, vertical transmission, EOS, or LOS. HIV-infected neonates, however, were at increased risk of EOS and LOS.