Comparison of the effect of penicillins versus erythromycin in preventing neonatal group B streptococcus infection in active carriers following preterm prelabor rupture of membranes

ObjectiveTo compare the incidence of neonatal group B streptococcus (GBS) infection in active GBS carriers with preterm prelabor rupture of membranes (PPROMs) after penicillins and erythromycin prophylaxis.Materials and methodsPatients diagnosed to have PPROM between 2004 and 2009 inclusive were treated using erythromycin (erythromycin group), ampicillin, amoxicillin or co-amoxiclav (penicillin group), or no antibiotics (control group) according to department protocols depending on their gestation and their GBS status at the time of presentation. Patients receiving both erythromycin and penicillins were included in the penicillin group. The incidence of neonatal GBS infection was compared between groups categorized according to the antibiotic regime received.ResultsA total of 680 women were diagnosed to have PPROM of which 85 (12.5%) were active GBS carriers. GBS isolates were 100% sensitive to penicillins but only 35% were sensitive to erythromycin. There were 16, 22, and 47 patients in the penicillin, erythromycin, and control groups, respectively. The incidence of neonatal GBS infection in the three groups was 0%, 36%, and 13%, respectively, and was statistically significant (p = 0.023).ConclusionPenicillins are more effective than erythromycin in preventing neonatal GBS infection in women with PPROM who were active GBS carriers. Because most women do not know their GBS status at the time of PPROM and it is practically difficult to identify the active carriers before delivery, ampicillin/amoxicillin should be used as a prophylactic antibiotic for active GBS carriers and women with unknown GBS carriage status to prevent neonatal GBS infection following PPROM.     

Reduced colonization of newborns with group B streptococci following washing of the birth canal with chlorhexidine

Possible measures for prevention of neonatal group B streptococcal (GBS) septicemia include active or passiv immunoprophylaxis and administration of penicillin to mothers and infants. In a previous study we have found GBS to be extremely sensitive to chlorhexidine. Furthermore vaginal washing with chlorhexidine diminished the recovery of GBS from parturients. In order to study the effect of chlorhexidine washing upon the colonization of newborns, a study group of chronic GBS carriers, i.e. women who were GBS positive in the 32-36 gestational week as well as during labor was selected. In 18 of these females chlorhexidine washing was performed prior to delivery while 33 chronic carriers served as controls. Screening during labor was performed in 945 consecutive patients. Cultures were collected from the external ear, throat and umbilicus of all infants within 5 minutes of birth and at day 4 of life. At birth 22% of the infants of the chlorhexidine washed mothers were colonized with GBS, in contrast to 52% of the infants from the chronic GBS carriers (p less than 0.05). The proportion of infants harboring GBS at day 4 were similar in the two groups (Tab. I). Among the 945 consecutively screened women, 164 harbored GBS and 54 (33%) of their 164 infants were colonized at birth. The colonization rate of the infants from chronic GBS carriers was significantly higher, 17 of 33 infants (p less than 0.05). This may reflect that the risk of contracting GBS by infants increases with the quantity of GBS in the birth channel.(ABSTRACT TRUNCATED AT 250 WORDS)     

A GBS culture collected shortly after GBS prophylaxis may be inaccurate

Objective: To determine whether a vaginal–rectal culture obtained after antibiotic therapy has begun accurately detects pre-existing colonization with group B streptococcus (GBS). Methods: A prospective cohort study of women presenting at in labor who were known to be colonized with GBS were recruited. A GBS culture was obtained prior to administration of intravenous penicillin prophylaxis and repeated 2 hours following the first dose of penicillin. The two results were compared. Results: Eighty subjects were recruited. Complete results were obtained for 61 (76 %) subjects. Of these, 47 (77 %) had a GBS positive on initial culture. Persistence of GBS 2 hours after antibiotic exposure was seen in 30/47 (64 %). Conversion from GBS positive to GBS negative status was seen in 17/47 (36%). Conclusions: A vaginal–rectal culture for GBS performed after antibiotic prophylaxis has commenced may not accurately reflect a patient’s GBS colonization status.     

Colonization with group B streptococcus in pregnant women taken into the care of unit K and hospitalized in the department of obstetric pathology]

Colonization with group B streptococci (GBS) in 714 pregnant women was investigated. Among 232 were hospitalised in department of pathological pregnancy and 512 were under ambulatory control. In 13.4% of hospitalised patients and 2.8% healthy pregnant women the colonization of vagina or throat with GBS was stated. The greatest percentage of vagina colonization was found in patients hospitalised in connection with gestosis or because of abortions, premature delivery and inanimate fetus. No correlation was found between range of GBS colonization and trimester of pregnancy. Almost all GBS strains proved to be susceptible for commonly used antibiotics but resistant to biseptol (88.2%). Patients of hospitalised group were more often colonized not only GBS but also other potentially pathogenic microorganisms.     

Management of group B Streptococcus in pregnant women with penicillin allergy

OBJECTIVE: To determine whether group B Streptococcus (GBS)-colonized pregnant women who report a history of penicillin allergy can safely undergo diagnostic evaluation to rule out or confirm the potential for an IgE-mediated (allergic) reaction to penicillin. STUDY DESIGN: Over 18 months, all pregnant women with GBS-positive vaginal/rectal cultures and a history of penicillin allergy were referred to the Department of Allergy and Immunology for a history and possible skin testing. Patients who had experienced anaphylaxis were advised to continue avoiding penicillin and were not skin tested. Women without such a history underwent immediate hypersensitivity (percutaneous and intradermal) testing using 2 penicillin reagents with controls. If skin testing was negative, intrapartum antimicrobial prophylaxis with intravenous penicillin was administered. RESULTS: Of 28 patients with both GBS colonization and "penicillin allergy," 25 (89%) had negative skin testing to penicillin and received intrapartum penicillin for GBS prophylaxis without adverse reactions. Skin testing was positive in 2 patients, and intrapartum penicillin was not administered. Penicillin skin testing was not performed on 1 patient due to a history of anaphylaxis from penicillin. CONCLUSION: These results indicate that most pregnant women reporting penicillin allergy undergo negative skin tests and are able to safely receive intrapartum penicillin GBS prophylaxis.     

Prevalence of colonisation with group B Streptococci in pregnant women of a multi-ethnic population in The Netherlands

OBJECTIVE: This study was performed to determine the prevalence of GBS and to identify GBS colonisation risk factors in a multicultural population of pregnant women in The Netherlands. We calculated predictive values of cultures in pregnancy for intrapartum GBS carriage. STUDY DESIGN: From a total of 1702 women visiting several antenatal outpatient departments, rectovaginal swabs were collected at 35-37 weeks' gestation. In 761 women swabs were repeated at time of delivery. Carriage of GBS late in third trimester and at time of delivery was analysed in relation to age, parity, ethnicity and socio-economic status. RESULTS: Twenty-one percent was GBS carrier late in pregnancy. Compared to Europeans, African women were at a higher risk (29%, RR 1.4, CI 1.1-1.7) and Asian women were at lower risk (13%, RR 0.6, CI 0.4-0.8) for GBS carriage. No differences in colonisation were found between women with respect to age, parity or socio-economic background. Positive predictive value of GBS carriage at 35-37 weeks' gestation for carriage at time of parturition was 79% and negative predictive value was 93%. CONCLUSIONS: It was not possible to identify a group of pregnant women at high risk for GBS colonisation. Predictive values of antenatal genital group B streptococci cultures at 35-37 weeks' gestation for intrapartum GBS carriage are lower than previously reported.     

Efficacy of intrapartum chemoprophylaxis less than 4 hours duration

Objective.?Current guidelines for prevention of group B streptococcus (GBS) early-onset infection recommend to administer antibiotic during labor at least 4?h prior to delivery (adequate prophylaxis). We aimed to determine if neonatal GBS colonization may be significantly decreased in case of inadequate (<4?h) duration of ampicillin prophylaxis.

Methods.?In prospective, cohort study, 167 infants born to 167 GBS culture-positive mothers without additional risk factors were enrolled. Cultures were collected both, at 10–24?h after birth (admission) and at discharge.

Results.?Among 137 infants born to mothers who received inadequate prophylaxis, 5 (3.6%, C.I.?=?0.5–6.8) were colonized (≥1 sites) at admission, at discharge, or both, at admission and discharge. Eighty-two women received prophylaxis?<2?h before delivery and two infants (2.4%) were colonized at discharge.

Eighteen (60.0%, C.I.?=?42.5–77.5) of 30 infants who were not exposed to prophylaxis were colonized at admission or both, at admission and discharge.

Colonization was significantly more frequent among infants born to untreated mothers with respect to infants born to women who received inadequate prophylaxis (either?<2 or?<4?h).

Conclusions.?In this selected group, inadequate prophylaxis significantly interrupted vertical colonization. This effect was evident even if prophylaxis started?<2?h before delivery.     

Ethical issues associated with routine screening and prophylaxis for group B streptococcus in pregnancy

An increased awareness of the impact of group B streptococcus (GBS) infection on neonataloutcome has prompted several seemingly discordant committee recommendations. Intrapartumantibiotics are effective in reducing the risk of neonatal morbidity when administered to a colonizedwoman who has a clinical condition that places her neonate at high risk for early-onset sepsis.However, less is known about the efficacy of prophylactic antibiotics in the colonized woman whodoes not have obvious risk factors. Some authorities have suggested that providers refrain fromadministering intrapartum antibiotics to colonized women who do not have any of these risk factors,primarily due to concerns about potential adverse reactions, selection of resistant pathogens, andcost-effectiveness. These recommendations may conflict with the desires of an informed womanwho weighs the real, albeit low, risk for serious neonatal disease against the lower perceived riskof adverse maternal sequelae from allergic reactions to the antimicrobial agents. Selective prophylaxisfor GBS disease that is limited to the colonized parturient with risk factors has the potentialfor creating conflict because maternal beneficence-based obligations of the physician may be atodds with maternal autonomy-based obligations. We believe that, given all currently availableinformation, providers have a moral obligation to discuss GBS screening and treatment issues withpatients. The potential for conflict between patient and physician at the time of delivery can beminimized through the use of preventive ethics, allowing patients to develop advance directivesregarding intrapartum management within the confines of reasonable and cost-effective care. Untila consensus is reached among experts, the most prudent approach would be to address such issuesproactively and individualize care based upon the overall estimation and anticipation of risk as wellas the patient's specific desires.     

Neonatal septicemia due to group B streptococci--perinatal risk factors and outcome of subsequent pregnancies

All cases of early onset group B streptococcal (GBS) septicemia in infants born at Karolinska Hospital 1975-1986 were reviewed. GBS-septicemia was diagnosed in 40 infants within the first five days of life. The incidence was 1.24 per 1000 births. Fifty-five percent of the infants were preterm and 48% were born more than or equal to 12 hours after rupture of membranes. Prematurity and/or prolonged rupture of membranes were present in 83% of all neonates with fatal outcome. Case fatality was 22%. Deliveries by both cesarean section (31%) and vacuum extraction (26%) were increased in the mothers when compared to an overall incidence of 14 and 12% (p less than 0.01). Twenty-four (89%) of 27 mothers had low type specific IgG antibodies against the infecting GBS-serotype. Late onset GBS-septicemia was diagnosed in only two infants during the period. Seventeen mothers went through 24 subsequent pregnancies. In 11 of those the mothers were colonized with GBS and 10 received penicillin prophylaxis during pregnancy and/or delivery. None of the infants born after prophylaxis were colonized with GBS. Two were born prematurely and all had an uneventful course; whereas one infant delivered at 26 weeks gestation of a colonized untreated mother died of GBS-septicemia. Screening of parturients at risk and selective antibiotic prophylaxis may help to prevent early onset GBS-septicemia.     

The effect of intrapartum chemoprophylaxis on the vertical transmission of group B streptococci

Summary. Intrapartum chemoprophylaxis with benzylpenicillin or erythromycin significantly reduced the rate of transmission of group B streptococci (GBS) from mothers colonized during pregnancy to their babies from 45% to 3% (P<0.001). None of the babies born to women who were given prophylaxis was colonized with GBS in the first 24 h of life. Six weeks after leaving hospital, however, 23% of the babies in the antibiotic group had become colonized with GBS compared with 44% in the control group. GBS strains resistant and tolerant to both benzylpenicillin and erythromycin were found in this study. Intrapartum chemoprophylaxis breaks the cycle of GBS transmission at birth and may be useful in preventing early onset GBS disease, but is unlikely to affect late onset infections.     

The effect of intrapartum chemoprophylaxis on the vertical transmission of group B streptococci

Intrapartum chemoprophylaxis with benzylpenicillin or erythromycin significantly reduced the rate of transmission of group B streptococci (GBS) from mothers colonized during pregnancy to their babies from 45% to 3% (P less than 0.001). None of the babies born to women who were given prophylaxis was colonized with GBS in the first 24 h of life. Six weeks after leaving hospital, however, 23% of the babies in the antibiotic group had become colonized with GBS compared with 44% in the control group. GBS strains resistant and tolerant to both benzyl-penicillin and erythromycin were found in this study. Intrapartum chemoprophylaxis breaks the cycle of GBS transmission at birth and may be useful in preventing early onset GBS disease, but is unlikely to affect late onset infections.     

Can group B streptococci cause symptomatic vaginitis?

BACKGROUND: Maternal cervicovaginal colonization with Lancefield group B streptococci (GBS) is an important risk factor for neonatal morbidity and mortality. About 15% of women are carriers of GBS. Usually, they are asymptomatic. CASES: We describe two patients with symptomatic vaginitis for which no apparent cause was found. Both patients were heavily colonized with GBS. After antibiotic treatment, both became asymptomatic and culture negative, but after recolonization with GBS, symptoms resumed. This phenomenon was repeatedly observed. After emergence of resistance to antibiotics, local application of chlorhexidine appeared to be the only useful treatment. CONCLUSION: We hypothesize that GBS-vaginitis may be a possible disease entity. Although at present it is not clear why some patients become symptomatic, we speculate that the immunologic response is somehow selectively hampered in such patients.     

Differences in innate immunologic response to group B streptococcus between colonized and noncolonized women

OBJECTIVE: To evaluate the functional capacity of granulocytes and monocytes from pregnant and nonpregnant women in relation to group B streptococcus (GBS) colonization status. METHODS: Engulfment of fluorescent GBS by peripheral blood phagocytes from GBS-colonized and noncolonized women was measured by flow cytometry. Intracellular superoxiode generated in response to GBS challenge to monocytes and granulocytes enriched from peripheral blood of these women was also measured by flow cytometry, and extracellular superoxide was determined by colorimetric assay. RESULTS: Monocytes and granulocytes from pregnant, GBS-colonized women engulfed significantly greater numbers of GBS than phagocytes from pregnant, noncolonized women. No difference in intracellular superoxide production was detected between any of the groups of women; however, monocytes from pregnant, colonized women released significantly more superoxide into the extracellular milieu than did granulocytes from the same women. No differences in extracellular release of superoxide were observed among noncolonized women whether they were pregnant or not. CONCLUSIONS: Monocytes from pregnant, colonized women engulf more GBS and release more of the superoxide into the extracellular environment, where it is unlikely to be an effective defense mechanism against intracellular bacteria. This suggests that components of the innate immune system that should serve in a protective role may function suboptimally, thereby contributing to the colonization process by GBS.     

Recurrent vaginal candidiasis. Results of a cohort study of sexual transmission and intestinal reservoir.

Yeast cultures from the oral cavity, vagina and rectum were obtained from 125 women experiencing an acute episode of recurrent candidal vaginitis. To investigate the role of sexual transmission, oral, penile and ejaculate cultures were also prepared from all the male sexual partners. The rates of oral and rectal Candida species colonization in the women were 36% (45/125) and 44.8% (56/125), respectively. The male partners' oral cavities were positive in 23.2% (29/125) and the penile coronal sulcus and seminal fluid in 16% (20/125) and 14.4% (18/125), respectively. The susceptibility of the isolated species to the main antimycotic drugs was ascertained with the agar diffusion method. Therapy in the women and the colonized sexual partners was carried out, eliminating the microorganism from every positive site. Control cultures were obtained two weeks after the completion of therapy, and follow-up was continued for one year. The overall clinical and microbiologic cure rate in the study group was 72% (95/125). The rate of relapse was not influenced by the treatment of Candida colonization of the female intestinal tract. The recurrence rate after treatment in the couples in which the man harbored yeast (oral cavity, penile coronal sulcus, seminal fluid) was lower (15.8% vs. 44.8%, P = .0019) than that recorded in the couples without sexual partner involvement. The identification and treatment of the male sexual partner's Candida colonization seems important in the prevention of recurrent vulvovaginitis.     

The efficacy of 2002 CDC guidelines in preventing perinatal group B Streptococcal vertical transmission: a prospective study

Objectives The aim of the current study is to evaluate the differences in the rate of perinatal group B streptococcal vertical transmission between women who correctly underwent the CDC 2002 guidelines and women who did not. Methods Two study groups: women who correctly underwent the CDC 2002 guidelines (study group 1) and women who did not (study group 2). Intrapartum chemoprophylaxis (IC) was administered to all pregnant women identified as GBS carrier. All newborns received, in the first hour of life, a culture based screening for GBS colonization. Results One thousand six hundred and sixty nine women were enrolled in the study. The 2002 CDC guidelines were correctly applied in 1273 (76.3%) subjects. There was no early-onset GBS disease. No statistically significant difference in the total number of colonized newborns between study group 1 (4.1%) and study group 2 (3.3%) was found. When the analysis was limited to women with positive GBS screening, a significant difference (P < 0.001) was observed in the number of colonized newborns between mothers who received IC during at least 4 h (group 1; 3.7%) and those who received an IC during less than 4 h (group 1; 12.3%). Conclusion The accurate application of the 2002 CDC guidelines is strongly supported but, to furthermore reduce the risk for GBS colonization and sepsis in the newborns, it appears desirable to identify additional and new prevention strategies.     

Is antenatal group B streptococcal carriage a predictor of adverse obstetric outcome?

OBJECTIVES: While early-onset neonatal GBS sepsis is positively associated with premature birth and prolonged rupture of membranes, there is debate in the literature as to whether maternal GBS colonization is a predictor of adverse obstetric outcome. This is a critical issue to resolve for appropriate management (expectant vs. interventional management) of the patient presenting with premature rupture of membranes, who has no overt signs of sepsis, but who is colonized with GBS. METHODS: Since 1981 it has been hospital policy to screen all public patients antenatally for genital carriage of GBS by collection of a low vaginal swab at 28-32 weeks. All patients colonized with GBS antenatally are given penicillin as intrapartum chemoprophylaxis. Review of all GBS-colonized antenatal patients for a 12-month period (580 of 4,495 patients) and a randomized (every fourth consecutive antenatal patient) number of noncolonized patients (958) was made. Lower vaginal GBS colonization and other risk factors for preterm delivery were assessed using univariate and multivariate generalized linear modeling. RESULTS: In the study group, the maternal GBS colonization rate was 12.9%. When cofounding variables were controlled in a multivariate analysis, the association between antepartum GBS colonization and preterm labor and preterm rupture of membranes was not significant. CONCLUSION: Maternal antenatal carriage of GBS does not predict preterm labor. Therefore it is appropriate that expectant management occur for a GBS-colonized woman who ruptures her membranes, is not in labor, and has no evidence of sepsis.     

Prenatal antibiotic treatment does not decrease group B streptococcus colonization at delivery

Objective:

To evaluate whether an outpatient antibiotic regimen decreased group B streptococcal (GBS) colonization to preclude the use of intrapartum antibiotics.

Methods:

A double-blind randomized controlled trial evaluating prenatal oral amoxicillin versus placebo with the primary outcome of GBS colonization at the time of labor.

Results:

Of those patients receiving both amoxicillin and a repeat culture at the time of labor, 6 of the 14 (43%) tested positive for GBS colonization. Given persistent GBS colonization of 67% (10/15) in the placebo group, treatment with amoxicillin did not significantly impact colonization at the time of delivery (P = 0.20).

Conclusion:

A regimen of outpatient amoxicillin was associated with persistent GBS colonization in 43% of women at the time of labor. Oral prenatal antibiotic prophylaxis against GBS does not sufficiently reduce colonization to preclude intrapartum intravenous antibiotics.     

Comparison of rapid tests for detection of group B streptococcal colonization.

Accurate rapid detection of maternal lower genital tract colonization with group B streptococci (GBS) in high-risk patients is essential for selective institution of intrapartum antibiotic treatment to reduce neonatal GBS infection. In this study, pure GBS isolates were used to evaluate five commercially available rapid tests in terms of speed, ease of use, and sensitivity. The products tested were Directigen, Equate, Bactigen, PathoDx, and Phadebact. Although each test could be performed relatively quickly, the ease of performance and level of sensitivity (10(5) to 10(8) CFU/ml) varied markedly. Quantitative cultures obtained from 17 known GBS carriers showed concentrations ranging from less than 10(2) to greater than 10(8) CFU/gm of vaginal material. Since only 40% of the women had greater than or equal to 10(5) CFU/gm of vaginal material, it appears that many colonized women would not be identified by these rapid tests.     

Risk factors for group B streptococcal colonization in pregnant women at term: prospective study of 294 cases

OBJECTIVE: To determine the rate and risk factors for group B streptococcus (GBS) colonization in term pregnancies. PATIENTS AND METHODS: Vaginal and anal cultures were prospectively conducted in 294 parturient on admission for term vaginal delivery. RESULTS: Thirty-eight (12.92%) parturient had positive GBS cultures. None of the studied risk factors (age, education status, nulliparity, previous obstetric problem, twin pregnancy and diabetes) was statistically predictive of maternal colonization. All the isolated GBS were sensitive to the penicillin G. DISCUSSION AND CONCLUSION: Systematic screening strategy of GBS close to the delivery on all pregnant women is desirable.     

Antibiotic resistance patterns of group B streptococcal clinical isolates

OBJECTIVES: To determine the in vitro resistance of group B streptococcus (GBS) to 12 antibiotics. To determine if there has been any decrease in sensitivity to the penicillins or other antibiotics currently used for GBS chemoprophylaxis in pregnant women. Find suitable alternative antibiotics to penicillin. Find an antibiotic that will have minimal selective pressure for resistance among the endogenous resident vaginal microflora. METHODS: The antibiotic susceptibility profiles of 52 clinical isolates of GBS were evaluated to 12 antibiotics: ampicillin, azithromycin, cefamandole, cefazolin, ceftriaxone, ciprofloxacin, clindamycin, erythromycin, nitrofurantoin, ofloxacin, penicillin and vancomycin. Antibiotic sensitivities were determined using disk diffusion and microdilution methods according to the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS). RESULTS: All isolates were sensitive to vancomycin, ofloxacin, ampicillin, ciprofloxacin, nitrofurantoin and penicillin. However, the following number of clinical isolates exhibited intermediate or decreased sensitivity, nine (17%) to ampicillin, eight (15%) to penicillin, 14 (32%) to ciprofloxacin and one (2%) to nitrofurantoin. Thirty-one percent of the isolates were resistant to azithromycin and ceftriaxone, 19% to clindamycin, 15% to cefazolin and 13% to cefamandole. Eighteen (35%) of the clinical isolates tested were resistant to 6 of the 12 antibiotics tested. CONCLUSIONS: The relatively high rates of resistance for 6 of the 12 antibiotics tested suggest that for women allergic to penicillin and colonized with GBS, antibiotic sensitivities to their isolates should be determined. The antibiotic selected for intrapartum chemoprophylaxis should be guided by the organism's antibiotic sensitivity pattern. Patients with GBS bacteriuria should be treated with nitrofurantoin.