Early-onset Group B Streptococcus Infection Research Articles

Group B streptococcal disease in Portuguese infants younger than 90 days

Background:Group B streptococcus (GBS) is the most common isolate in mother-related infection in newborns.Aims:To evaluate the epidemiology of GBS infection in the first 90 days after birth; to determine if...

Clinical and economic outcomes for term infants associated with increasing administration of antibiotics to their mothers

Implementation of national guidelines for the prevention of group B streptococcal (GBS) infections has led to an increase in intrapartum antibiotic use and reduction in early-onset GBS infections in newborns. Other outcomes, including the clinical diagnosis of sepsis in term infants, treatment with antibiotics, length of stay, and cost have not been described. To examine these outcomes, we performed an analysis of maternal and newborn data collected between 1998 and 2002 of 130 447 in-hospital births of newborns >or=37 weeks gestation and their mothers from a large vertically integrated healthcare organisation in Utah. The main outcome measures included: (i) the number of women delivering at term who received intravenous antibiotics; (ii) the number of newborns treated for 'clinical sepsis', which was defined as receiving antibiotics for >72 h and the number of newborns who received antibiotics for <or=48 h, i.e. a 'rule-out-sepsis' course. We also compared the lengths of stay and variable costs of infants whose mothers received antibiotics with those whose mothers did not. We found that the proportion of mothers who received intravenous antibiotics rose from 26.8% in 1998 to 40.6% in 2002 (P < 0.0001). The proportion of newborns treated for clinical sepsis ranged from 1.2% to 1.4% over the 5-year period. (P for trend = 0.04). After controlling for maternal chorioamnionitis, delivery by caesarean section and maternal GBS status, newborns of mothers who received antibiotics were significantly more likely to be treated for clinical sepsis than were newborns of mothers who had not received them [adjusted OR = 3.3; 95% CI 2.9, 3.8]. The average length of stay for newborns whose mothers were treated with antibiotics was 55.8 h compared with 41.6 h for those not treated (P < 0.0001). The cost of caring for newborns whose mothers received antibiotics was $740 compared with $638 for those whose mothers had not received them (P < 0.001).

Perinatal Group B Streptococcal Infections and the New Guidelines

After completing this article, readers should be able to: 1. Describe the current literature on surveillance studies and patient outcomes regarding group B Streptococcus (GBS) disease. 2. Discuss the current perinatal GBS prevention guidelines. 3. Describe the limitations of the “limited evaluation” in assessing newborns at risk for GBS disease. 4. Delineate the proposed management of asymptomatic infants at risk for GBS disease, with the goal of decreasing unnecessary testing and avoiding prolonged hospitalization. Group B Streptococcus (GBS), also known as S agalactiae , is an encapsulated gram-positive bacterium that is a common inhabitant of the human gastrointestinal and genitourinary tracts. Despite recent reductions in incidence, it remains the most common cause of neonatal bacterial infections in most developed countries. The most desirable approach suggested to eliminate neonatal GBS infection is the use of GBS vaccines prior to or early in pregnancy. However, until effective GBS vaccines become available, screening pregnant women for GBS colonization and providing intrapartum antibiotic prophylaxis (IAP) will continue to be the mainstay for prevention of GBS infection in neonates, as suggested by the Centers for Disease Control and Prevention (CDC). A 70% decline in the rate of early-onset GBS disease followed the introduction of the first national consensus guidelines in 1996. In 2002, new national guidelines were released based on evidence that the screening-based strategy was superior to a risk factor-based strategy for preventing GBS infections in the neonate. As a result of many obstetricians adopting the screening-based strategy, CDC data from 2004 showed a further decline in the incidence of early-onset GBS infection to 0.34 cases per 1,000 live births. This surpasses the Healthy People 2010 objective of a reduction in the incidence of early-onset disease to 0.5 cases per 1,000 live births for all races. It should be mentioned that different countries may demonstrate different results, but …

Association of Intrapartum Antibiotic Exposure and Late-Onset Serious Bacterial Infections in Infants

Recommendations to prevent vertical transmission of group B Streptococcus (GBS) infections have resulted in many women's receiving antibiotics during labor with an associated reduction in early-onset GBS infections in their newborn infants. However, a potential relationship of intrapartum antibiotics (IPA) to the occurrence of late-onset (7-90 days) serious bacterial infections (SBIs) in term infants has not been reported. The objectives of this study were to determine whether infants with late-onset SBI were more likely than healthy control infants to have been exposed to IPA and whether there was a greater likelihood of antibiotic resistance in bacteria that were isolated from infants who had an SBI and had been exposed to IPA compared with those who had not. We used a case-control design to study the first objective. Cases were previously healthy full-term infants who were hospitalized for late-onset SBI between the ages of 7 and 90 days. Control subjects were healthy full-term infants who were known not to have an SBI in their first 90 days. Cases and control subjects were matched for hospital of delivery. In the second part of the study, rates of antibiotic resistance of bacteria that were isolated from infected infants were compared for those who had and had not been exposed to IPA. Ninety case infants and 92 control subjects were studied. Considering all types of IPA, more case (41%) than control infants (27%) had been exposed to IPA (adjusted odds ratio [OR]: 1.96; 95% confidence interval [CI]: 1.05-3.66), after controlling for hospital of delivery. The association was stronger when IPA was with broad-spectrum antibiotics (adjusted OR: 4.95; 95% CI: 2.04-11.98), after controlling for hospital of delivery, penicillin IPA, maternal chorioamnionitis, and breastfeeding. Bacteria that were isolated from infected infants who had been exposed to IPA were more likely to exhibit ampicillin resistance (adjusted OR: 5.7; 95% CI: 2.3-14.3), after controlling for hospital of delivery, but not to other antibiotics that are commonly used to treat SBI in infants. After adjusting for potential confounders, infants with late-onset SBI were more likely to have been exposed to IPA than noninfected control infants. Pathogens that cause late-onset SBI were more likely to be resistant to ampicillin when the infant had been exposed to intrapartum antibiotics.

The prevention of neonatal group B streptococcal disease: a report by a working group of the Medical Screening Society

Streptococcus agalactiae, or Lancefield group B streptococcus (GBS), is the most frequent cause of serious bacterial sepsis, including neonatal meningitis, in UK neonates. Early-onset neonatal GBS infection, but not late-onset, can be prevented by screening to identify high-risk pregnancies and administering penicillin during delivery. A vaccine has been developed as an alternative means of prevention but it is awaiting a randomized trial before being available for general use. In this review we examine the published literature to assess the morbidity and mortality attributable to neonatal GBS infection, quantify the screening performance of the two alternative modes of screening (microbiological and risk factor based), review the evidence on the efficacy of the vaccine, and estimate the numbers of deaths and cases of serious disability that each strategy in turn might prevent in the UK, in order to assess the most effective means of prevention for the UK.

Invasive group B streptococcal disease in infants: a 19-year nationwide study. Serotype distribution, incidence and recurrent infection

During the period 1984-2002, 472 cases of invasive group B streptococcal (GBS) disease in infants aged 0-90 days in Denmark were registered. The overall incidence was 0.4/1000 live births. Most infants (73%) had early-onset GBS infection with 53% registered within the first day. Serotype III predominated (59%) with other serotypes as follows: Ia (16%), Ib (8%), NT (7%), II (6%), other serotypes (5%). Recurrence of GBS infection was registered in six infants, and the interval with no antibiotic therapy varied from 2 to 39 days. The serotypes of the isolates obtained from first and second episodes were identical (serotype III in five, and serotype Ia in one infant). Paired isolates were indistinguishable by PFGE and antibiotic susceptibility testing. Invasive GBS infections in infants are still a problem in Denmark, and recurrent infections are registered in 1% of these infants.

Effects of Intrapartum Penicillin Prophylaxis on Intestinal Bacterial Colonization in Infants

Early-onset group B streptococcal (GBS) infections remain a leading cause of morbidity and mortality in infants. To prevent the vertical transmission of GBS and neonatal GBS infection, guidelines recommend intrapartum penicillin or amoxicillin prophylaxis. This intrapartum antibiotic prophylaxis (IAP) is suspected to favor colonization by antibiotic-resistant bacteria. However, the effects of this prophylaxis on the patterns of acquisition of gastrointestinal bacterial flora in infants have never been studied. We collected stool samples from 3-day-old infants born to mothers who received intrapartum amoxicillin (antibiotic-exposed group; n = 25) and to untreated mothers (non-antibiotic-exposed group; n = 25). The groups were matched for factors known to affect intestinal microbial colonization: gestational age, type of delivery, and type of feeding. Qualitative and quantitative differential analyses of the bacterial flora in stool samples were performed. Similar numbers of infants in the non-antibiotic-exposed and antibiotic-exposed groups were colonized by aerobic bacteria and amoxicillin-resistant enterobacteria (75 and 77%, respectively) (P = 0.79). In contrast, significantly fewer infants in the antibiotic-exposed group than in the non-antibiotic-exposed group were colonized by anaerobic bacteria, especially Clostridium (12 and 40%, respectively) (P < 0.05). Regarding intestinal bacterial colonization, the differences between antibiotic-exposed and non-antibiotic-exposed infants were remarkably few. The only statistically significant effect was the reduced initial bacterial colonization by Clostridium in the antibiotic-exposed group. In our study, the use of IAP did not favor colonization by beta-lactam-resistant bacteria. However, further evaluations are required to highlight the potential risks of the widespread use of antibiotics to prevent early-onset GBS infection.

Neonatal Early-Onset Group B Streptococcal Disease in the Era of Intrapartum Chemoprophylaxis: Residual Problems

Guidelines for intrapartum antibiotic prophylaxis appear to have reduced the incidence of early-onset group B streptococcal (GBS) infection, but it still is a major cause of early-onset neonatal sepsis and infectious mortality in newborn infants in the United States. The authors reviewed 92 infants admitted to one of two university-affiliated nurseries in the years 1992 through 2001 at age 7 days or less with culture-proved GBS disease. The mean age at the onset of symptoms was 2.5 hours. Only one infant was diagnosed after death. No intrapartum prophylaxis was given to 68 women, half of whom were known before delivery to have risk factors for early-onset GBS infection. Of 32 infants with clinical risk factors, 22 had a gestational age less than 37 weeks. Less frequent risk factors were ruptured amniotic membranes for 18 hours or longer, intrapartum maternal fever, and previous GBS bacteriuria. In several cases, there was more than one risk factor. Four of 22 women having rectovaginal cultures for GBS were positive, but proper culture medium was not consistently used. Intrapartum prophylaxis was withheld in 18 women who were screen-negative for GBS colonization. Fourteen of 68 infected infants required extracorporeal membrane oxygenation and three infants died. The absence of clinical risk factors or known maternal colonization did not protect these infants. Twenty-four women received what were thought to be adequate doses of antibiotic prophylaxis, most frequently ampicillin. All of these women had risk factors and a majority had multiple risk factors. Five of six studies for maternal rectovaginal colonization were positive. In 15 cases, prophylaxis lasted less than 4 hours. All infants became ill in the first 24 hours of life. Two required extracorporeal membrane oxygenation and one died. These findings suggest that early-onset GBS disease can occur despite appropriate prophylaxis. Possible improvements include a rapid and practical test for GBS colonization, development of effective vaccines, and studies of adjunctive postnatal prophylaxis.

Invasive group B streptococcal infections in Finland: a population-based study.

We analyzed surveillance data on group B streptococcus (GBS) infection in Finland from 1995 to 2000 and reviewed neonatal cases of early-onset GBS infection in selected hospitals in 1999 to 2000. From 1995 to 2000, 853 cases were reported (annual incidence 2.2–3.0/100,000 population). We found 32–38 neonatal cases of early-onset GBS disease per year (annual incidence 0.6–0.7/1,000 live births). In five hospitals, 35% of 26 neonatal cases of early-onset GBS infection had at least one risk factor: prolonged rupture of membranes, preterm delivery, or intrapartum fever. Five of eight mothers screened for GBS were colonized. In one case, disease developed despite intrapartum chemoprophylaxis. Although the incidence of early-onset GBS disease in Finland is relatively low, some geographic variation exists, and current prevention practices are suboptimal. Establishing national guidelines to prevent perinatal GBS is likely to reduce the incidence of the disease.

Early-onset group B streptococcal infection after a combined maternal and neonatal group B streptococcal chemoprophylaxis strategy.

In January 1995, a combined maternal and neonatal protocol for prevention of early-onset group B streptococcal (GBS) infection was implemented that consisted of a risk factor-based approach for maternal intrapartum chemoprophylaxis using ampicillin combined with a single intramuscular dose of penicillin given to all newborns within 1 hour of delivery. The objective of this study was to review the cases of early-onset GBS infections that occurred from 1995 to 1999 to identify factors associated with their continued occurrence despite implementation of a GBS chemoprophylaxis protocol. Infants <or=72 hours of age with early-onset GBS infection born at Parkland Memorial Hospital in Dallas from January 1995 to December 1999 were identified through a prospective laboratory-based surveillance system. Maternal and infant medical records were reviewed for clinical and demographic data. There were 32 cases (0.47/1000 live births) of early-onset GBS infection for the 5-year period. This represented a 76% reduction compared with the rate from 1986 to 1994 (1.95/1000), when there was no protocol for GBS chemoprophylaxis. Thirteen cases (41%) did not have any identifiable maternal risk factor. Of the 19 cases (59%) with risk factors, maternal intrapartum fever was the most frequent (15 [79%]), followed by prematurity (6 [32%]) and prolonged rupture of membranes (6 [32%]). Among the 19 mothers with risk factors, 15 (79%) mothers received intrapartum chemoprophylaxis, and 12 (80%) of the 15 mothers had intrapartum fever. Only 33% of mothers with risk factors received >or=2 doses of intrapartum chemoprophylaxis, and among those with intrapartum fever, 25% received >or=2 doses. None of the 32 infants with early-onset GBS infection received the combination of intrapartum ampicillin and postnatal penicillin. A combined obstetric and neonatal chemoprophylaxis protocol significantly reduced early-onset GBS infection. Maternal intrapartum fever was the most frequent risk factor associated with failure of chemoprophylaxis.

Perinatal Group B Streptococcal Infections: Past, Present, and Future

After completing this article, readers should be able to: 1. Differentiate early-onset from late-onset group B streptococcal (GBS) disease. 2. Describe the current literature on patient outcome and surveillance studies regarding GBS disease. 3. Compare and contrast the screening-based and risk factor-based strategies. 4. Delineate the adverse consequences of widespread use of intrapartum antibiotics. 5. Discuss the need to revise the 1996 perinatal GBS prevention guidelines based on newly available data. Group B Streptococcus (GBS) remains the leading cause of neonatal bacterial infections in the United States. Prior to using intrapartum antibiotic prophylaxis in the 1990s, an average of 8,000 cases of early-onset GBS infection occurred in the United States annually (approximately 2 cases per 1,000 live births). Approximately 4% to 6% of affected newborns died. Some surviving infants had disabilities such as mental retardation, hearing loss, or vision loss. Not only were infants affected, but parturient women also developed clinical infection with GBS, accounting for more than 50,000 maternal infections each year, including bacteremia, postpartum endometritis, chorioamnionitis, and urinary tract infections. Other adverse outcomes of pregnancy associated with GBS colonization include early fetal loss, premature rupture of membranes, and preterm delivery of low-birthweight infants. Intrapartum prophylaxis has decreased the incidence of early-onset GBS sepsis by 70% and narrowed the gap between affected African-American and Caucasian infants by 75%. However, 1999 Centers for Disease Control and Prevention (CDC) surveillance data estimated that 1,600 infants still become infected each year. Therefore, effective GBS screening, improved compliance, and vigilance must prevail until an effective vaccine becomes available. Moreover, continued surveillance of patient outcome is imperative to minimize unintended consequences of widespread intrapartum antibiotic prophylaxis, such as the emergence of resistant GBS and nonGBS organisms. Beta-hemolytic streptococci of the Lancefield Group B classification ( S agalactiae ) were considered commensal organisms until the late 1930s, when severe infections affected both …

Strategy to prevent neonatal early-onset group B streptococcal (GBS) disease in the Netherlands

Early-onset group B streptococcal (GBS) infection can be prevented by intrapartum antibiotic prophylaxis. In the USA the effectiveness of this strategy was demonstrated after the introduction of formal guidelines in 1996. In Europe prevention strategies for early-onset GBS infection have not been implemented universally. In 1998 the Dutch Society of Paediatrics and the Dutch Society of Obstetrics and Gynaecology posted conjoint guidelines for the prevention of early-onset GBS disease based on currently available knowledge and the local situation. These guidelines will be discussed in this overview.

Prevention of neonatal group B streptococcal disease: A combined intrapartum and neonatal protocol

Objective: We sought to assess the efficacy of a clinical protocol to reduce the incidence of early-onset neonatal group B Streptococcus (GBS) infection. Study design: We assessed neonatal sepsis from GBS and other organisms with use of a before-after study design to evaluate the effects of implementation of combined intrapartum antimicrobial prophylaxis given selectively to mothers with GBS risks and penicillin G given to all neonates. Results: In 1994, early-onset GBS infection developed in 31 of 13,887 live births (2.2/1000), 13 preterm and 18 term cases. After implementation of the prophylaxis protocol (1995), 6 of 13,527 live births had early-onset GBS (0.4/1000) (P < .001). There were no preterm (P = .0004) and 6 term GBS cases (P = .02). The efficacy continued through 1999 (0.5/1000) without an increase in neonatal infections from other bacteria. Conclusion: Combined maternal and infant antimicrobial prophylaxis can significantly and safely reduce rates of early-onset GBS infection in both preterm and term infants. (Am J Obstet Gynecol 2002;186:618-26.)

Early-onset neonatal group B streptococcal sepsis: intrapartum antibiotic prophylaxis in the clinical setting.

To evaluate how guidelines for the use of intrapartum antibiotics for the prevention of early-onset Group B streptococcal infection are utilized in a clinical setting. Review of maternal/infant records for the year 1993 in a perinatal center. Intrapartum antibiotics were administered to 77.8% of 443 Group B streptococcus (GBS)-colonized women. There were 452 infants born to these mothers, of which four developed GBS infection. During the same period, an additional 11 infants with GBS infection were born to women with "negative" or "unknown" GBS status (the women did not receive intrapartum antibiotics). Infants of GBS-colonized women who had not receive antibiotics were more likely to develop infection than GBS negative or unknown status, odds ratio 9.0, 95% confidence interval (2.8-29.1). This study supports the use of intrapartum antibiotics as an important means of preventing early-onset neonatal GBS infection but demonstrates problems that may be encountered in the clinical application of guidelines for intrapartum antibiotic prophylaxis.

The influence of intrapartum antibiotics on the clinical spectrum of early-onset group B streptococcal infection in term infants.

The use of intrapartum antibiotics to prevent early-onset group B streptococcal (EOGBS) infection has left pediatricians in a quandary about the appropriate evaluation and treatment of infants at risk for this infection. The aim of this study was to determine whether intrapartum antibiotic prophylaxis changed the constellation and timing of onset of clinical signs of group B streptococcal (GBS) infection in term infants. We conducted a retrospective chart review of infants who had EOGBS infection and were born in Southern California Kaiser Permanente Hospitals from 1988 through 1996. Objective criteria were used to ascertain maternal risk of infection, intrapartum antibiotic prophylaxis, and onset of clinical signs of infection. Three hundred nineteen infants with EOGBS sepsis, bacteremia, or clinically suspected infection were identified from a population of 277 912 live births. Of the 172 term infants with culture-positive infection who had clinical signs of infection, 95% exhibited them in the first 24 hours of life. All of the infants exposed to intrapartum antibiotics became ill within the first 24 hours of life. Exposure to antibiotics during labor did not change the clinical spectrum of disease or the onset of clinical signs of infection within 24 hours of birth for term infants with EOGBS infection. A 48-hour stay is not required to monitor asymptomatic term infants exposed to intrapartum antibiotics for onset of GBS infection.

The Changing Spectrum of Group B Streptococcal (GBS) Infection in Infants of Saudi Arabia

This study describes the incidence, clinical presentation and outcome of neonatal Group B streptococcal (GBS) infection in a Saudi Arabian Hospital. Charts of all neonates with GBS infection admitted to our hospital during a 5-year period (1990-1994) were reviewed retrospectively. Of the 29,601 live births, 23 neonates had GBS infection, giving an overall incidence rate of 0.8 per 1000 live births. The incidence rate appeared to increase from 0.2 per 1000 live births in 1990 to 1.2 per 1000 live births in 1994 (not statistically significant (P=0.07)). Of the 23 neonates with GBS infection, 16 (70%) were full term infants (gestation ≥37 weeks). In contrast, 7 (30%) were preterm infants (gestation <37 weeks). Ten (44%) mothers had premature rupture of membrane. Intrapartum fever and/or urinary tract infection was observed in 9% of the mothers. Nineteen (82%) of the neonates had early onset GBS infection, whereas only 4 infants (18%) had late-onset infection. Blood and CSF cultures were positive in 21 (91%) and 5 (21%), respectively. Complications of GBS infection were as follows: sepsis without focus of infection 15 (65%); meningitis 5 (22%); pneumonia 3 (13%); urinary tract infection 2 (9%). None of these complications had any significant association with the onset of infection (P>0.1). The overall case-fatality rate was 9%.The incidence of GBS infection appears to be increasing in Saudi neonates and measures to prevent perinatal transmission need to emphasized and implemented.

Preventing early-onset group B streptococcal sepsis: strategy development using decision analysis.

To evaluate recommended strategies for prevention of early-onset group B streptococcal infections (EOGBS) with reference to strategies optimized using decision analysis. The EOGBS attack rate, prevalence and odds ratios for risk factors, and expected effects of prophylaxis were estimated from published data. Population subgroups were defined by gestational age, presence or absence of intrapartum fever or prolonged rupture of membranes, and presence or absence of maternal group B streptococcus (GBS) colonization. The EOGBS prevalence in each subgroup was estimated using decision analysis. The number of EOGBS cases prevented by an intervention was estimated as the product of the expected reduction in attack rate and the number of expected cases in each group selected for treatment. For each strategy, the number of residual EOGBS cases, cost, and numbers of treated patients were calculated based on the composition of the prophylaxis group. Integrated obstetrical-neonatal strategies for EOGBS prevention were developed by targeting the subgroups expected to benefit most from intervention. Reductions in EOGBS rates predicted by this decision analysis were smaller than those previously estimated for the strategies proposed by the American Academy of Pediatrics in 1992 (32.9% vs 90.7%), the American College of Obstetricians and Gynecologists in 1992 (53.8% vs 88.8%), and the Centers for Disease Control and Prevention in 1996 (75.1% vs 86.0%). Strategies based on screening for GBS colonization with rectovaginal cultures at 36 weeks or on use of a rapid test to screen for GBS colonization on presentation for delivery, combining intrapartum prophylaxis for selected mothers and postpartum prophylaxis for some of their infants, would require treatment of fewer patients and prevent more cases (78.4% or 80.1%, respectively) at lower cost. No strategy can prevent all EOGBS cases, but the attack rate can be reduced at a cost <$12 000 per prevented case. Supplementing intrapartum prophylaxis with postpartum ampicillin in a few infants is more effective and less costly than providing intrapartum prophylaxis for more mothers. Better intrapartum screening tests offer the greatest promise for increasing efficacy. Integrated obstetrical and neonatal regimens appropriate to the population served should be adopted by each obstetrical service. Surveillance of costs, complications, and benefits will be essential to guide continued iterative improvement of these strategies.

Intrapartum antibiotics and early onset neonatal sepsis caused by group B Streptococcus and by other organisms in Australia. Australasian Study Group for Neonatal Infections.

Early onset group B streptococcal (EOGBS) infection, the major neonatal infection in industrialized countries, can be prevented by intrapartum antibiotics, but population studies are lacking. This study aimed to determine the incidence of early onset infections caused by group B Streptococcus (GBS) and other organisms in Australia and to assess intrapartum antibiotic use. Longitudinal, prospective surveillance of neonatal infections in Australian neonatal units from 1991 to 1997. Early onset infection defined as clinical sepsis in first 48 h after birth, with positive cultures of blood or cerebrospinal fluid or positive urine GBS antigen detection. The incidence of EOGBS sepsis fell from 2.0 per 1000 live births (95% confidence interval, 1.4, 2.5) in 1991 to 1993, to 1.3 (1.2, 1.4) in 1993 to 1995, to 0.5 (0.4, 0.7) in 1995 to 1997 (P < 0.0001). The incidence in Aboriginal babies was 5.2 (1.8, 8.6) in 1991 to 1993, 5.1 (3.0, 7.2) in 1993 to 1995 and 1.8 (1.1, 2.5) in 1995 to 1997 (P < 0.05). The incidence of early onset infections caused by organisms other than GBS also fell, from 1.2 per 1000 live births (0.8, 1.7) in 1991 to 1993, to 0.8 (0.7, 0.9) in 1993 to 1995 and 0.5 (0.3, 0.7) in 1995 to 1997 (P < 0.0001). In 1991, 3 of 9 study hospitals had a formal policy on intrapartum antibiotic use, whereas in 1997 all 11 hospitals had a formal policy (P=0.002). A steady fall in EOGBS infections in Australia from 1991 to 1997 has been associated with increasing use of intrapartum antibiotics. Increased antibiotic use is probably causal in the fall in GBS, because the incidence of early onset infections caused by other organisms has also fallen.

Neonatal Group B Streptococcal Infection in a Managed Care Population

Objective In a health maintenance organization population, we determined the incidence of early-onset (at less than or equal to 7 days) neonatal group B streptococcal (GBS) disease, the sensitivity and prevalence of labor risk factors, the adherence to a protocol for intrapartum anti-biotics, and the costs for care of and outcomes of affected infants. Methods Mothers and infants at four health maintenanceorganization hospitals in northern California in 1989 to 1995 were studied retrospectively using computerized databases and chart review. In 1994, two of the four hospitals had adopted protocols similar to the ACOG recommendations for intrapartum antibiotics for women with labor risk factors (preterm, temperature 100.4F or higher, or rupture of membranes (ROM) 18 hours or more). Results Among the 79,940 live births, the incidence of early-onset neonatal GBS infection was higher among preterm than among term infants (3.1 compared with 0.9 per 1000). Before protocol adoption, 68% of 65 infants with GBS had mothers with labor risk factors. Approximately 18% of all mothers had labor risk factors: 7.7% had preterm delivery, and 10.6% had term delivery with fever and/or ROM 18 hours or more. At the two hospitals that adopted GBS protocols, GBS incidence was reduced from 1.3 per 1000 in the preprotocol period to 0.8 per 1000 in the postprotocol period (P = .08). Six cases of neonatal GBS occurred after protocol adoption. Of these, four were not preventable under the protocol and two might have been preventable if protocol had been followed. Three of the 19 preterm infants with group B streptococcal disease died. Conclusion Risk factor–based protocols hold some promise to reduce GBS disease, but clinical strategies to promote protocol adherence are needed.

Neonatal Group B Streptococcal Infection in a Managed Care Population

Objective: In a health maintenance organization population, we determined the incidence of early-onset (at less than or equal to 7 days) neonatal group B streptococcal (GBS) disease, the sensitivity and prevalence of labor risk factors, the adherence to a protocol for intrapartum antibiotics, and the costs for care of and outcomes of affected infants. Methods: Mothers and infants at four health maintenance organization hospitals in northern California in 1989 to 1995 were studied retrospectively using computerized databases and chart review. In 1994, two of the four hospitals had adopted protocols similar to the ACOG recommendations for intrapartum antibiotics for women with labor risk factors (preterm, temperature 100.4F or higher, or rupture of membranes (ROM) 18 hours or more). Results: Among the 79,940 live births, the incidence of early-onset neonatal GBS infection was higher among preterm than among term infants (3.1 compared with 0.9 per 1000). Before protocol adoption, 68% of 65 infants with GBS had mothers with labor risk factors. Approximately 18% of all mothers had labor risk factors: 7.7% had preterm delivery, and 10.6% had term delivery with fever and/or ROM 18 hours or more. At the two hospitals that adopted GBS protocols, GBS incidence was reduced from 1.3 per 1000 in the preprotocol period to 0.8 per 1000 in the postprotocol period ( P = .08). Six cases of neonatal GBS occurred after protocol adoption. Of these, four were not preventable under the protocol and two might have been preventable if protocol had been followed. Three of the 19 preterm infants with group B streptococcal disease died. Conclusion: Risk factor–based protocols hold some promise to reduce GBS disease, but clinical strategies to promote protocol adherence are needed.