Group B streptococcal colonization: Prevalence and impact of smoking in women delivering term or near term neonates in a large tertiary care hospital in the southern United States

Sexual activity, vaginal symptoms, maternal perineal hygiene behavior, and constipation on ano-vaginal colonization of group B streptococcus in near term pregnancy

BACKGROUND

Maternal Group B Streptococcus (GBS) colonization is influenced by many factors but results are inconsistent. Consideration of antenatal risk factors may help inform decision making on GBS microbiological culture screening where universal screening is not standard of care. We sought to identify independent predictors of GBS colonization at 34-37 weeks gestation incorporating vaginal symptoms, perineal hygiene measures, sexual activity, and a potential novel factor, constipation.

METHODS

In this prospective cross-sectional study, 573 women at 34-37 weeks gestation had an ano-vaginal swab taken and sent for selective culture for GBS. Women were asked about vaginal bleeding, discharge, irritation and candidiasis, antibiotic use during pregnancy, ano-vaginal hygiene practices such as douching and perineal cleansing after toileting, sexual intercourse related activities, and a potential novel factor for GBS carriage, constipation. Maternal basic demographics and obstetric-related characteristics were also collected. Bivariate analyses were performed to identify associates of GBS colonization. All variables with p < 0.05 found on bivariate analysis were then included into a model for multivariable binary logistic regression analysis to identify independent risk factors for GBS colonization.

RESULTS

GBS colonization was found in 235/573 (41.0%) of participants. Twenty six independent variables were considered for bivariate analysis. Eight were found to have p < 0.05. Following adjusted analysis, six independent predictors of GBS colonization were identified: ethnicity, previous neonatal GBS prophylaxis, antenatal vaginal irritation, antibiotic use, recent panty liner use, and frequency of sexual intercourse. Vaginal discharge and perineal cleansing were not associated after adjustment. Recent douching and constipation were not associated on bivariate analysis.

CONCLUSION

The identification of independent predictors of GBS colonization in late pregnancy may inform the woman and care provider in their shared decision making for microbiological screening at 35-38 weeks gestation in locations where universal GBS screening is not standard of care.

ETHICS OVERSIGHT

This study was approved by the Medical Ethics Committee of University Malaya Medical Centre (UMMC) on August 9, 2022, reference number 2022328-11120.

Group B streptococcal prevalence in internal organs and placentas of deceased neonates and stillbirths in South Asia

OBJECTIVE

Group B streptococcus (GBS) has been associated with adverse pregnancy outcomes, but few prospective studies have assessed its prevalence in low- and middle-income country settings. We sought to evaluate the prevalence of GBS by polymerase chain reaction (PCR) in internal organ tissues and placentas of deceased neonates and stillbirths.

DESIGN

This was a prospective, observational study.

SETTING

The study was conducted in hospitals in India and Pakistan.

POPULATION

Pregnant women with stillbirths or preterm births were recruited at delivery, as was a group of women with term, live births, to serve as a control group.

METHODS

A rectovaginal culture was collected from the women in Pakistan to assess GBS carriage. Using PCR, we evaluated GBS in various tissues of stillbirths and deceased neonates and their placentas, as well as the placentas of live-born preterm and term control infants.

MAIN OUTCOME MEASURES

GBS identified by PCR in various tissues and the placentas; rate of stillbirths and 28-day neonatal deaths.

RESULTS

The most obvious finding from this series of analyses from India and Pakistan was that no matter the country, the condition of the subject, the tissue studied or the methodology used, the prevalence of GBS was low, generally ranging between 3% and 6%. Among the risk factors evaluated, only GBS positivity in primigravidae was increased.

CONCLUSIONS

GBS diagnosed by PCR was identified in <6% of internal organs of stillbirths and neonatal deaths, and their placentas, and control groups in South Asian sites. This is consistent with other reports from South Asia and is lower than the reported GBS rates from the USA, Europe and Africa.

Near-term pregnant women in the Dominican Republic experience high rates of Group B Streptococcus rectovaginal colonization with virulent strains

Maternal colonization with Group B Streptococcus (GBS) is an important cause of stillbirth, prematurity, and serious infection and death in infants worldwide. Resource constraints limit prevention strategies in many regions. Maternal GBS vaccines in development could be a more accessible prevention strategy, but data on geographic variations in GBS clones are needed to guide development of a broadly effective vaccine. In the Dominican Republic (DR), limited data suggest that pregnant women experience GBS colonization at rates among the highest globally. We aimed to determine the prevalence of maternal rectovaginal GBS colonization and describe clonal characteristics of colonizing strains in the DR. A cross-sectional study assessed rectovaginal GBS colonization in 350 near-term pregnant women presenting for routine prenatal care at an urban tertiary center in the DR. Rectovaginal samples were tested with chromogenic Strep B Carrot Broth and cultured for confirmatory whole-genome sequencing. In a secondary analysis, participants' demographics and histories were assessed for association with GBS colonization. Rectovaginal GBS colonization occurred in 26.6% of women. Serotypes Ia, Ib, II, III, IV, and V were detected, with no one serotype predominating; serotype III was identified most frequently (21.5%). Virulent and emerging strains were common, including CC17 (15.1%) and ST1010 (17.2%). In this first characterization of maternal GBS serotypes in the DR, we found high rates of rectovaginal colonization including with virulent and emerging GBS strains. The serotypes observed here are all targeted by candidate hexavalent GBS vaccines, suggesting effective protection in the DR.

Prevalence, Antimicrobial Susceptibility Pattern and Associated Factors of Group B Streptococcus Among Pregnant Women Attending Antenatal Care at Bule Hora University Teaching Hospital, Southern Ethiopia

Background

In many parts of the world, Group B Streptococcus (GBS) is a major cause of maternal and neonatal illness and mortality. It has a negative impact on neonatal and pregnancy outcomes. A worrisome problem in Ethiopia is the unknown rate of antibiotic resistance and the risk factors connected to GBS infections.

Objective

This study was to determine the prevalence, antibiotic susceptibility pattern, and related variables of Group B Streptococcus among pregnant women receiving prenatal treatment conducted at Bule Hora University Teaching Hospital, Southern Ethiopia, between June 1 and August 30, 2022.

Methods

An institutional-based cross-sectional study was conducted among 213 pregnant women attending antenatal care at Bule Hora University Teaching Hospital. Data on sociodemographic and related factors were gathered using structured questionnaires. The study's participants were selected using the consecutive sampling method. The lower vaginal/rectum area was brushed with a sterile cotton swab to capture the vaginal/rectum swab sample, which was then examined using microbiological techniques. The Kirby-Bauer disc diffusion method was used to assess antibiotic susceptibility in GBS isolates. Logistic regression analysis was performed on the data using SPSS version 26. It was deemed statistically significant when the p-value was 0.05 with a 95% confidence interval (CI).

Results

The overall prevalence of GBS was 16.9% (CI: 0.12-0.23). A history of prematurity of the membrane (AOR: 3.35, 95% CI: 1.19-9.45), a history of stillbirth (AOR: 2.88, 95% CI: 1.07-7.71), and preterm delivery history (AOR: 3.41, 95% CI: 1.31-8.89) (p 0.05) were independent predictors of GBS infection. Cefepime had the highest resistance at 58.3%. Most GBS isolates showed high susceptibility to vancomycin (97.2%) and ampicillin (91.7%). Multidrug resistance was 13.9%.

Conclusion

The prevalence of GBS was considerably high among pregnant women in this study. This finding emphasises the need for routine screening and testing of antimicrobial susceptibility to provide antibiotic prophylaxis and minimise newborn infection and comorbidity.

Group B Streptococci Vaginal-Recto Colonization, Vertical Transmission to Newborns, Antimicrobial Susceptibility Profile and Associated Factors in Selected Health Facilities of Bahir Dar City: A Cross-Sectional Study

BACKGROUND

Group B streptococci (GBS) is an important pathogen involved in stillbirths, neonatal deaths and neurological defects, and the occurrence of multi-drug resistance (MDR) is an alarming issue. This study determined the prevalence of GBS colonization in pregnant women and newborns, the proportion of vertical transmission, antimicrobial susceptibility profiles of isolates, and the factors associated with colonization and vertical transmission.

METHODS

A cross-sectional study was conducted from March 1, 2021 to June 30, 2021, at selected health facilities of Bahir Dar city. Vaginal-recto swabs from 292 pregnant women and pooled ear, nasal and umbilical swabs from 292 newborns were collected. GBS were identified following standard microbiological protocols. Antimicrobial susceptibility testing was performed using modified Kirby-Bauer disk diffusion method and interpreted by the accepted 2020 CLSI M100 guidelines. Logistic regression analysis was computed.

RESULTS

Overall, 54 (18.5%) of pregnant women and 22 (7.5%) of newborns had GBS colonization. The proportion of GBS vertical transmission was 22 (40.7%). Group B Streptococcus isolates scored susceptibility to penicillin, ampicillin and vancomycin with 88.9%, 90.7%, and 96.3% for pregnant women and 86.4%, 90.9% and 95.9% for newborns, respectively. A high percentage of non-susceptibility was found for clindamycin and erythromycin with 33.3% and 25.9% for pregnant women and 31.8% and 22.7% from newborns, respectively. Besides, 19 (35.2%) GBS from pregnant women and 8 (36.4%) from newborns were MDR. Group B streptococci colonization was significantly associated with delivery before 37th week of gestation (AOR=2.77, 95% CI 1.14-6.68) and history of stillbirth (AOR=3.13, 95% CI 1.13-8.70).

CONCLUSION

Pregnant women vaginal-recto GBS colonization and transmission to newborns connected with MDR are a matter of concerns. Although non-susceptible GBS isolates are obtained, penicillin and vancomycin are relatively effective. The use of clindamycin, erythromycin and ceftriaxone should be guided by antimicrobial susceptibility testing. Genetic analysis is recommended to exactly identify the epidemiology of GBS strains, vertical transmission and antimicrobial resistance at the country level.