Invasive group B streptococcal disease in children beyond early infancy

Neonatal Group B Streptococcus Disease

Group B Streptococcus (GBS) is an important cause of neonatal sepsis in term and preterm infants. Because GBS colonizes human genitourinary and gastrointestinal tracts, a significant focus of neonatal GBS disease prevention is to interrupt vertical transmission of GBS from mother to infant during parturition. Routine antepartum GBS screening in pregnant women, as well as widespread use of intrapartum antibiotic prophylaxis, have aided in overall reductions in neonatal GBS disease during the past 3 decades. However, neonatal GBS disease persists and may cause mortality and significant short- and long-term morbidity among survivors. Herein, we highlight contemporary epidemiology, microbial pathogenesis, and the clinical presentation spectrum associated with neonatal GBS disease. We summarize obstetric recommendations for antenatal GBS screening, indications for intrapartum antibiotic prophylaxis, and considerations for antibiotic selection. Finally, we review national guidelines for risk assessment and management of infants at risk for GBS disease.

Invasive Group B Streptococcal Disease In Childhood

Invasive group B streptococcal disease in childhood is uncommon and occupies a unique clinical niche. We present 10 children, 1-17 years of age, with invasive group B streptococcal disease from 2010 to 2020. Seven had conditions predisposing to infection and 3 had no identifiable risk factors. With appropriate consideration of pathogenesis, source control, and treatment, all children recovered.

Group B streptococcus — a pathogen not restricted to neonates

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Invasive group B streptococcal (GBS) infections can occur in any age group, not only neonates.

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Most of the patients are elderly or have severe concomitant diseases.

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Screening-based intrapartum antibiotic prophylaxis (based on maternal risk factors) significantly decreases very early-onset infections.

Objectives

This was a retropective study of invasive group B streptococcal (GBS) infections isolated from blood, cerebrospinal fluid (CSF), synovial fluid, peritoneal fluid, pleural fluid, pericardial fluid and corpus vitreum in a defined region in southwest Sweden over a 14-year period.

Design

Information on all invasive GBS infections was obtained from all four bacteriological laboratories in the region, with data obtained from individual patient records.

Results

GBS was isolated from normally sterile body fluids in 1244 samples (579 from females and 665 from males) from 1101 patients. Of these patients, 196 were neonates. The incidence in neonates (0–27 days) was 7.3 per 100 000 live births per year, but there was a significant decrease from 2012 when risk-factor-based intrapartum antibibiotic prophylaxis was implemented. The great majority of neonatal infections were very early-onset infections. The incidence rates in children (28 days to 17 years), adults (18–64 years) and elderly patients (≥ 65 years) were 1.3, 3.6, and 12.9 per 100 000 per year, respectively. The majority of children and adults had severe underlying diseases, but severe infections were also seen in individuals with no risk factors.

Conclusions

GBS is an important pathogen in all age groups. Intrapartum antibiotic prophylaxis significantly decreases very early-onset infections.

Group B Streptococcal Neonatal Meningitis

Neonatal bacterial meningitis is a devastating disease, associated with high mortality and neurological disability, in both developed and developing countries. Streptococcus agalactiae, commonly referred to as group B Streptococcus (GBS), remains the most common bacterial cause of meningitis among infants younger than 90 days. Maternal colonization with GBS in the gastrointestinal and/or genitourinary tracts is the primary risk factor for neonatal invasive disease. Despite prophylactic intrapartum antibiotic administration to colonized women and improved neonatal intensive care, the incidence and morbidity associated with GBS meningitis have not declined since the 1970s. Among meningitis survivors, a significant number suffer from complex neurological or neuropsychiatric sequelae, implying that the pathophysiology and pathogenic mechanisms leading to brain injury and devastating outcomes are not yet fully understood. It is imperative to develop new therapeutic and neuroprotective approaches aiming at protecting the developing brain. In this review, we provide updated clinical information regarding the understanding of neonatal GBS meningitis, including epidemiology, diagnosis, management, and human evidence of the disease's underlying mechanisms. Finally, we explore the experimental models used to study GBS meningitis and discuss their clinical and physiologic relevance to the complexities of human disease.

Breastfeeding and Risk of Late-Onset Group B Streptococcal Disease

BACKGROUND

Group B Streptococcus (GBS) is a major contributor to neonatal sepsis worldwide. Late-onset group B Streptococcus disease (LOGBS) and its risk factors remain poorly understood. The isolation of GBS from breast milk has been described in cases of LOGBS. This potential association has raised concerns for mothers and clinicians regarding the safety of ongoing breastfeeding. In this study, we aimed to investigate whether exposure to breast milk is associated with increased risk of LOGBS.

METHODS

A case-control study of LOGBS was conducted across 4 hospital networks in Victoria, Australia, including the 2 major tertiary pediatric centers in the state, to evaluate 11 years of data (2007-2017). Cases were captured initially from microbiology databases and recaptured with International Classification of Diseases discharge coding. Each case patient was matched with 4 controls to assess feeding status. Patients were matched for chronological age, gestation, discharge status, recruitment site, and calendar year.

RESULTS

We identified 92 cases of LOGBS: 73 cases on initial capture and 76 cases on the recapture analysis. Case patients were matched with 368 controls: 4 controls to each patient. Seventy-two patients were exposed to breast milk at the time of LOGBS (78.3%), compared with 274 controls (74.5%; odds ratio 1.2 [95% confidence interval 0.7-2.3]).

CONCLUSIONS

Breastfeeding was not associated with increased risk of LOGBS. Breast milk should not be tested for GBS during a first episode of LOGBS.

Device-Associated Menstrual Toxic Shock Syndrome

In the 1980s, menstrual toxic shock syndrome (mTSS) became a household topic, particularly among mothers and their daughters. The research performed at the time, and for the first time, exposed the American public as well as the biomedical community, in a major way, to understanding disease progression and investigation. Those studies led to the identification of the cause, Staphylococcus aureus and the pyrogenic toxin superantigen TSS toxin 1 (TSST-1), and many of the risk factors, for example, tampon use. Those studies in turn led to TSS warning labels on the outside and inside of tampon boxes and, as important, uniform standards worldwide of tampon absorbency labeling. This review addresses our understanding of the development and conclusions related to mTSS and risk factors. We leave the final message that even though mTSS is not commonly in the news today, cases continue to occur. Additionally, S. aureus strains cycle in human populations in roughly 10-year intervals, possibly dependent on immune status. TSST-1-producing S. aureus bacteria appear to be reemerging, suggesting that physician awareness of this emergence and mTSS history should be heightened.

Susceptibility to infection in early life: a growing role for human genetics

The unique vulnerability to infection of newborns and young infants is generally explained by a constellation of differences between early-life immune responses and immune responses at later ages, often referred to as neonatal immune immaturity. This developmental view, corroborated by robust evidence, offers a plausible, population-level description of the pathogenesis of life-threatening infectious diseases during the early-life period, but provides little explanation on the wide inter-individual differences in susceptibility and resistance to specific infections during the first months of life. In this context, the role of individual human genetic variation is increasingly recognized. A life-threatening infection caused by an opportunistic pathogen in an otherwise healthy infant likely represents the first manifestation of an inborn error of immunity. Single-gene disorders may also underlie common infections in full-term infants with no comorbidities or in preterm infants. In addition, there is increasing evidence of a possible role for common genetic variation in the pathogenesis of infection in preterm infants. Over the past years, a unified theory of infectious diseases emerged, supporting a hypothetical, age-dependent general model of genetic architecture of human infectious diseases. We discuss here how the proposed genetic model can be reconciled with the widely accepted developmental view of early-life infections in humans.

Management of Infants at Risk for Group B Streptococcal Disease

Group B streptococcal (GBS) infection remains the most common cause of neonatal early-onset sepsis and a significant cause of late-onset sepsis among young infants. Administration of intrapartum antibiotic prophylaxis is the only currently available effective strategy for the prevention of perinatal GBS early-onset disease, and there is no effective approach for the prevention of late-onset disease. The American Academy of Pediatrics joins with the American College of Obstetricians and Gynecologists to reaffirm the use of universal antenatal microbiologic-based testing for the detection of maternal GBS colonization to facilitate appropriate administration of intrapartum antibiotic prophylaxis. The purpose of this clinical report is to provide neonatal clinicians with updated information regarding the epidemiology of GBS disease as well current recommendations for the evaluation of newborn infants at risk for GBS disease and for treatment of those with confirmed GBS infection. This clinical report is endorsed by the American College of Obstetricians and Gynecologists (ACOG), July 2019, and should be construed as ACOG clinical guidance.

Group B Streptococcal infection in neonates and colonization in pregnant women: An epidemiological retrospective analysis

BACKGROUND

Group B Streptococcus (GBS) infection is one of the major causes of neonatal morbidity and mortality. Universal GBS screening with intrapartum antibiotic prophylaxis (IAP) in pregnant women were initiated in 2012 in Taiwan. This study aimed to analyze the most recent maternal GBS colonization rate and the changes in neonatal GBS infection rate from 2011 to 2016.

METHODS

All pregnant women and their live born neonates between January 2011 and June 2016 were retrospectively reviewed. Whether GBS screening was done, screening results, presence of risk factors, the use of antibiotics, and neonatal outcome were analyzed. In addition, hospitalized neonates diagnosed with GBS infections were retrieved for comparison of early onset disease (EOD) (<7 days) and late onset disease (LOD) (≥7 days).

RESULTS

A total of 9535 women delivered babies during the study period. The maternal GBS screening rate was 71.0% and the colonization rate was 22.6%. The overall neonatal invasive GBS infection rate was 0.81 per 1000 live births and the vertical transmission rate was 1.2%. After 2012, the invasive neonatal GBS infection rate declined from 1.1-1.6‰ to 0.6-0.7‰ in 2014 and thereafter, the GBS EOD incidence rate declined from 2.8‰ to 0.0-0.6‰, but the LOD incidence rate remained approximately 0.7‰. Infants with EOD had strong association with obstetric risk factors.

CONCLUSIONS

Taiwan's universal GBS screening with IAP program reduced the incidence rate of neonatal GBS EOD to be lower than 1‰ after 2012. Pediatricians still should pay attention to infants with GBS LOD since its incidence rate remained unchanged.

Group B streptococcal disease in infants in the first year of life: a nationwide surveillance study in Japan, 2011-2015

PURPOSE

This study aimed to describe the epidemiology of childhood group B streptococcus (GBS) disease including late late-onset disease (LLOD) and to clinically characterize recurrent cases and twin-sibling cases in Japan.

METHODS

We collected information on infants (<1 year of age) with invasive GBS disease and institutional information about births and transfers through a nationwide questionnaire between 2011 and 2015.

RESULTS

We identified 133 infants with early-onset disease (EOD), 274 late-onset disease (LOD), and 38 LLOD from 149 institutes. The case fatality rate (CFR) of EOD, LOD, and LLOD was 4.5, 4.4, and 0%, respectively. CFR in EOD was significantly (P < 0.001) associated with preterm birth, but not that in LOD and LLOD. Twenty-nine percent of infants with meningitis (49/169) had neurologic sequelae. We showed clinical details of 12 recurrent cases that accounted for 2.8% of the total patients, and 4 sets of both twins affected; 4 of 12 recurrent cases and 3 of 4 twin-sibling sets were also associated with preterm birth. Based on the livebirth number of 581,488, the instituted-based incidence of EOD, LOD, and LLOD was estimated as 0.09 (95% CI 0.06-0.11), 0.12 (95% CI 0.11-0.14), and 0.01 (95% CI 0.01-0.02) per 1000 livebirths, respectively.

CONCLUSIONS

CFR of EOD and LOD in Japan is comparable with that in high-income European countries or the United States, and their incidence is much lower. Our findings also describe the clinical details of LLOD, recurrent infections, and infections in twin siblings. This study is the largest among Asian childhood GBS studies ever reported.

The first case of recurrent ultra late onset group B streptococcal sepsis in a 3-year-old child

Group B streptococcus (GBS) is a commonly recognized cause of sepsis and meningitis in neonatal and young infants. Invasive GBS infection is classified into early onset GBS disease (EOD, day 0-6), late onset GBS disease (LOD, day 7-89) and ultra late onset GBS disease (ULOD, after 3 months of age). ULOD is uncommon and recurrence is especially rare. We present the first recurrent case of ULOD GBS sepsis in 3-year-old girl with a past medical history of hydrops fetalis and thoracic congenital lymphatic dysplasia. The first episode presented as sepsis at 2 years 8 months of age. The second episode occurred as sepsis with encephalopathy at 3 years 1 months of age. During each episode, the patient was treated using intravenous antimicrobials and her condition improved. Serotype examination was not performed in the first episode, but GBS type V was serotyped in the second episode. ULOD over 1 year of age is quite rare and may recur.

Natural acquired group B Streptococcus capsular polysaccharide and surface protein antibodies in HIV-infected and HIV-uninfected children

Group B Streptococcus (GBS) is a major cause of invasive disease in young infants and also in older immunocompromised individuals, including HIV-infected persons. We compared naturally acquired antibody titres to GBS polysaccharide and surface protein antigens in HIV-uninfected and HIV-infected children aged 4-7 years. A multiplex Luminex immunoassay was used to measure IgG concentrations against GBS capsular polysaccharides (CPS) for serotypes Ia, Ib, III and V; and also extracellular localizing proteins which included cell-wall anchored proteins: Fibrinogen binding surface Antigen (FbsA), GBS Immunogenic Bacterial Adhesin (BibA), Surface immunogenic protein (Sip), gbs0393, gbs1356, gbs1539, gbs0392; and lipoproteins gbs0233, gbs2106 and Foldase PsrA. HIV-infected children (n=68) had significantly lower IgG GMT compared to HIV-uninfected (n=77) children against CPS of serotype Ib (p=0.012) and V (p=0.0045), and surface proteins Sip (p<0.001) and gbs2106 (p=0.0014). IgG GMT against GBS surface proteins: FbsA, gbs1539, gbs1356, gbs0392, gbs0393 and Foldase PsrA were significantly higher in HIV-infected children (p<0.004). Moreover, amongst HIV infected children, IgG GMT to GBS surface proteins were higher in those with CD4⁺ lymphocyte counts <500cell/μL compared to those who had CD4⁺ lymphocyte count ⩾500cell/μL with the exception of Sip. The increased susceptibility to invasive GBS disease in HIV-infected individuals could be due to the lower serotype specific capsular antibody and possibly due to lower antibody to some of the GBS proteins such as Sip and gbs2106.

Late, Late-Onset Group B Streptococcus Cellulitis With Bacteremia

Group B streptococcus (GBS) infection remains a leading cause of serious neonatal and early infantile infection. As the infection often presents with nonspecific symptoms, and is associated with underlying bacteremia, prompt investigation and treatment is required. We report a case of late, late-onset GBS infection with bacteremia in a 94-day-old boy experiencing cellulitis of the left hand. Although late-onset disease or late, late-onset disease has been reported to be common among infants with underlying conditions such as premature birth, immunocompromised status, trauma, or among those using medical devices, no such underlying medical condition predisposed this infant to invasive GBS infection. Recent reports including the present case underscore the risk of GBS infection among previously healthy infants beyond the neonatal period. Thus, clinicians should especially be aware of unusual presentations of GBS invasive disease with bacteremia.

Invasive streptococcal disease: a review for clinicians

INTRODUCTION

Streptococci are a genus of Gram-positive bacteria which cause diverse human diseases. Many of these species have the potential to cause invasive infection resulting from the presence of bacteria in a normally sterile site.

SOURCES OF DATA

Original articles, reviews and guidelines.

AREAS OF AGREEMENT

Invasive infection by a streptococcus species usually causes life-threatening illness. When measured in terms of deaths, disability and cost, these infections remain an important threat to health in the UK. Overall they are becoming more frequent among the elderly and those with underlying chronic illness. New observational evidence has become available to support the use of clindamycin and intravenous immunoglobulin in invasive Group A streptococcal disease.

AREAS OF CONTROVERSY

Few interventions for the treatment and prevention of these infections have undergone rigorous evaluation in clinical trials. For example, the role of preventative strategies such as screening of pregnant women to prevent neonatal invasive Group B streptococcal disease needs to be clarified.

FUTURE PROSPECTS

Studies of invasive streptococcal disease are challenging to undertake, not least because individual hospitals treat relatively few confirmed cases. Instead clinicians and scientists must work together to build national and international networks with the aim of developing a more complete evidence base for the treatment and prevention of these devastating infections.

Late and very late onset group B Streptococcus sepsis: one and the same?

BACKGROUND

This study aimed to describe the clinical characteristics of group B Streptococcus (GBS) sepsis in infants aged 4-90 days [late onset (LO)] compared to infants >90 days of age [very late onset (VLO)].

METHODS

Microbiology records at Children's Medical Center Dallas were screened. Demographic, clinical, and outcome data were collected for infants with GBS recovered from blood or cerebrospinal fluid culture from January 1, 2006 to July 1, 2012.

RESULTS

Totally 48 infants were identified (42 LO, 6 VLO). Infants with VLO sepsis had lower median gestational age (28.5 vs. 39 weeks gestation, P<0.001) and longer median nursery admissions (8.8 vs. 0.5 weeks, P=0.004). When gestational age was controlled for, there were no differences in clinical presentation, intensive care unit admission, length of stay, neurodevelopmental outcome, and mortality. Infants with VLO sepsis were more likely to receive vancomycin (83% vs. 33%, P=0.02) or third-generation cephalosporins (83% vs. 24%, P=0.009), and more likely to continue on those agents even after GBS was identified.

CONCLUSIONS

Infants with VLO sepsis had lower gestational ages and longer nursery stays than infants with LO sepsis. Beyond age at presentation, there were no significant differences in clinical presentations, hospital course, frequency of neurodevelopmental sequelae, and mortality in infants presenting with LO vs. VLO GBS sepsis. Infants with VLO sepsis were more likely to receive empiric broad spectrum antimicrobials and more likely to continue receiving broad therapy even following GBS identification.

Staphylococcal and streptococcal superantigen exotoxins

SUMMARY This review begins with a discussion of the large family of Staphylococcus aureus and beta-hemolytic streptococcal pyrogenic toxin T lymphocyte superantigens from structural and immunobiological perspectives. With this as background, the review then discusses the major known and possible human disease associations with superantigens, including associations with toxic shock syndromes, atopic dermatitis, pneumonia, infective endocarditis, and autoimmune sequelae to streptococcal illnesses. Finally, the review addresses current and possible novel strategies to prevent superantigen production and passive and active immunization strategies.

Group B streptococcal meningitis in infants beyond the neonatal period

OBJECTIVES

To describe the clinico-bacteriological profile, and early outcomes of infants diagnosed with Group B streptococcus (GBS) meningitis.

METHODS

This was a retrospective review of infants (aged 1 mo to 2 y) diagnosed with GBS meningitis in a tertiary care hospital in New Delhi from October 2010 through January 2012. The clinico-bacteriological data and early outcomes of infants with suspected bacterial meningitis and a positive CSF latex agglutination test for GBS were studied. The CSF samples were subjected to PCR for broad spectrum 16s ribosomal DNA and the GBS species specific gene, the scpB.

RESULTS

Twenty seven patients (13 boys, and 14 girls) were diagnosed with GBS meningitis during the study period. Broad spectrum 16s ribosomal DNA PCR was performed on 18 of the 27 CSF samples. Sixteen were positive. All these 16 were also positive for the species specific scpB gene. The median duration of hospital stay was 7 d (range 1-72 d). Nine patients died. One patient each developed ventriculitis, optic atrophy and hydrocephalus. Overall, 12 patients had a complete recovery at discharge.

CONCLUSIONS

GBS must be considered in the etiology of bacterial meningitis in Indian infants.

Streptococcus agalactiae toxic shock-like syndrome: two case reports and review of the literature

We present 2 patients with Streptococcus agalactiae toxic shock-like syndrome and review another 11 well-reported cases from the literature. Streptococcal toxic shock-like syndrome is a devastating illness with a high mortality rate, therefore we stress the importance of early supportive management, antimicrobial therapy, and surgical intervention. Toxic shock-like syndrome is likely to be underestimated in patients with invasive Streptococcus agalactiae infection who present with shock. Early diagnosis requires high suspicion of the illness, along with a thorough mucocutaneous examination. Streptococcus agalactiae produces uncharacterized pyrogenic toxins, which explains the ability of the organism to cause toxic shock-like syndrome.

Very late onset infections in the neonatal intensive care unit

OBJECTIVE

We sought to determine the risk factors, incidence, and mortality of very late onset bacterial infection (blood, urine, or cerebrospinal fluid culture positive occurring after day of life 120) in preterm infants.

STUDY DESIGN

A retrospective observational cohort study of all very low birth weight infants cared for between day of life 120 and 365 in 292 neonatal intensive care units in the United States from 1997 to 2008.

RESULTS

We identified 3918 infants who were hospitalized beyond 120 days of life. Of these, 1027 (26%) were evaluated with at least 1 culture (blood, urine, or cerebrospinal fluid), and 276 (27%) of the evaluated infants had 414 episodes of culture-positive infection. Gram-positive organisms caused most of the infections (48%). The risk of death was higher in infants with positive cultures (odds ratio; 10.5, 95% confidence interval [7.2-15.5]) or negative cultures (4.8, [3.5-6.7]) compared to infants that were never evaluated with a culture (p<0.001). Mortality was highest with fungal infections (8/24, 33%) followed by Gram-positive cocci (40/142, 28%).

CONCLUSIONS

Important predictive risk factors for early and late onset sepsis (birth weight and gestational age) did not contribute to risk of developing very late onset infection. Evaluation for infection (whether positive or negative) was a significant risk factor for death. GPC and fungal infections were associated with high mortality.

Ultra late onset group B streptococcal sepsis with acute renal failure in a child with urethral obstruction: a case report

Introduction

Group B streptococci are a well-known cause of early and late onset sepsis. In neonates and older children gram-negative bacteria are mostly found in urinary tract infections and urosepsis. In adults predisposing factors for group B streptococci urinary tract infection may include diabetes mellitus and chronic renal failure.

Case presentation

We present a rare case of a five-month-old Caucasian boy with ultra late onset urosepsis and acute renal failure caused by group B streptococci serotype V. Excretion urography showed a subvesical obstruction that consequently was surgically corrected after antibiotic treatment of the acute infection.

Conclusions

Group B streptococci serotype V, urogenitary tract malformations, previous hospitalization and medical interventions may be important risk factors for the development of ultra late onset Group B streptococci sepsis in non-neonates.

[Group B streptococcal bacteremia in a 10-year-old girl undergoing corticosteroid therapy]

Group B streptococcus (GBS), a major cause of neonate and pediatric sepsis and meningitis, rarely causes invasive infection beyond infancy. We report the case of a 10-year-old girl developing GBS bacteremia during corticosteroid therapy for chronic idiopathic thrombocytopenic purpura. Brought to the emergency room due to sudden high fever and abdominal pain, she was in compensated shock. White blood cell count was 19,600/mm3 and C-reactive protein 0.18 mg/dL. She was diagnosed with sepsis and admitted for evaluation. Cefotaxime (100 mg/kg/day) administration and fluid replacement were begun immediately after blood culture. Her condition improved over the next 6 hours and she was afebrile by the next day. GBS isolated from blood had a serotype of Ib. Based on routine susceptibility testing, this strain was susceptible to penicillin, cephem, carbapenem, erythromycin, clindamycin, and vancomycin, but resistant to quinolone, including levofloxacin (MIC > or = 8.0 microg/mL) and gatifloxacin (MIC > or = 4.0 microg/mL). She was discharged on hospital day 8. This is, to our knowledge, the first report of pediatric meningitis-free GBS bacteremia in Japan. Physicians should therefore be aware of the possibility of invasive GBS infection such as bacteremia in this age group, especially during immunosuppressive therapy, because epidemiological studies in the US have showed significant mortality in those aged 1 to 14 years old with invasive GBS.

Late and ultra late onset Streptococcus B meningitis: clinical and bacteriological data over 6 years in France

BACKGROUND

Group B Streptococcus (GBS) is one of the leading causes of sepsis and meningitis in newborn. The objective of this study was to describe the characteristics of GBS meningitis in children aged between 7 and 89 days (late onset disease - LOD group) and to compare them with children aged more than 3 months (ultra late onset disease - ULOD group).

METHODS

Clinical and biological data were gathered by ACTIV/GPIP (a nationwide active surveillance network). The study population included 242 children hospitalized between 2001 and 2006 for GBS meningitis (220 in the LOD group and 22 in the ULOD group).

RESULTS

Univariate analysis revealed that gestational age (GA) was significantly lower in the ULOD group as compared with the LOD group (respectively 35.6 weeks vs. 37.9 weeks, p = 0.002). Prevalence of early preterm birth (before the 32nd week GA) was significantly higher in the ULOD group than in the LOD group (32% vs. 7%, p = 0.002). No significant difference was found between the two groups for biological characteristics of lumbar puncture, GBS serotypes, complications and survival rate.

CONCLUSION

These data suggest that LOD and ULOD would be the same clinical and bacteriological entity, except for prematurity, which seems significantly associated with ULOD.

Identification and immunoreactivity of proteins released from Streptococcus agalactiae

The aim of the present study was to identify released proteins of Streptococcus agalactiae and to investigate their immunoreactivity with human sera to determine whether such proteins might be viable as carrier proteins in conjugate vaccines. Infections with S. agalactiae are the leading cause of sepsis and meningitis in neonates. Vaccination of women of childbearing age would be a desirable alternative to intrapartum antibiotic prophylaxis, but factors that mediate S. agalactiae invasive disease and virulence are poorly defined. Capsule-based vaccines have shown only low immunogenicity to date, and interest has shifted towards S. agalactiae proteins, either as candidate vaccine antigens or as carrier proteins for serotype-specific S. agalactiae polysaccharides. In this study, some major released proteins of S. agalactiae could be identified, including molecules known to be present on the surface of bacterial cells but not previously described as released proteins, such as CAMP factor, a phosphocarrier protein, aldolase, enolase, PcsB, and heat-shock protein 70. Serotype-specific differences in the protein patterns of extracellular products and immunoreactivity with human sera could be detected by SDS-PAGE and Western blot. The identification of unexpected released proteins may indicate secondary functions for these proteins. In addition, the widespread immunoreactivity of these proteins with human sera as shown by Western blot indicates that released proteins may be promising candidates as carrier proteins in conjugate vaccines.

Clinical microbiology of bacterial and fungal sepsis in very-low-birth-weight infants

Twenty percent of very-low-birth-weight (<1500 g) preterm infants experience a serious systemic infection, and despite advances in neonatal intensive care and antimicrobials, mortality is as much as threefold higher for these infants who develop sepsis than their counterparts without sepsis during their hospitalization. Outcomes may be improved by preventative strategies, earlier and accurate diagnosis, and adjunct therapies to combat infection and protect the vulnerable preterm infant during an infection. Earlier diagnosis on the basis of factors such as abnormal heart rate characteristics may offer the ability to initiate treatment prior to the onset of clinical symptoms. Molecular and adjunctive diagnostics may also aid in diagnosing invasive infection when clinical symptoms indicate infection but no organisms are isolated in culture. Due to the high morbidity and mortality, preventative and adjunctive therapies are needed. Prophylaxis has been effective in preventing early-onset group B streptococcal sepsis and late-onset Candida sepsis. Future research in prophylaxis using active and passive immunization strategies offers prevention without the risk of resistance to antimicrobials. Identification of the differences in neonatal intensive care units with low and high infection rates and implementation of infection control measures remain paramount in each neonatal intensive care unit caring for preterm infants.

Invasive group B streptococcal infections in Sweden: incidence, predisposing factors and prognosis

OBJECTIVES

To study the incidence, clinical manifestations, concomitant conditions and case-fatality rate in patients with invasive group B Streptococcus (GBS) infections in the Göteborg area (mean population 582,666) of Sweden during 1981-95.

DESIGN

Patients were identified from the records of the Department of Clinical Bacteriology. Clinical data were obtained from hospital records.

RESULTS

GBS was isolated from blood, cerebrospinal fluid or other sterile body fluids from 211 patients with 215 infectious episodes; 108 in neonates, and 107 in non-neonates. The incidence was 2.4/100,000 per year, with the highest rates in neonates and in persons 65 years old or older. The incidence in neonates was 0.92/1,000 live births. The most common manifestation was septicemia with unknown focus. Of the neonates, 54% were full term and had no underlying conditions. Of the non-neonates, 15% had no underlying conditions. The most common underlying conditions were preterm delivery in neonates, and arteriosclerotic disease and diabetes mellitus in non-neonates. The case-fatality rates were 13% in neonates and 16% in non-neonates.

CONCLUSIONS

GBS is an important pathogen in neonates and in adults with concomitant conditions. The morbidity and mortality rates necessitate research to develop GBS vaccines both for women of fertile age and for patients with a wide variety of underlying diseases.

Group B streptococcal meningitis in a 5-year-old boy

Group B Streptococcus (Streptococcus agalactiae) is a well-known cause of early and late onset infections in neonates and very young infants. Recently attention has focused on the changing spectrum of invasive Group B Streptococcus (GBS) disease, including children beyond early infancy and non-pregnant adults. There is very little information available on invasive GBS infection especially meningitis in pediatric population older than three months of age. We report a case of uncomplicated meningitis due to GBS in a previously healthy 5-year-old boy. The literature on infection especially meningitis caused by Group B Streptococcus beyond infancy is reviewed.

Spinal epidural abscesses in children: a 15-year experience and review of the literature

We reviewed medical records and laboratory and diagnostic evaluations for 8 pediatric patients with spinal epidural abscesses who were treated during the last 15 years at our institution. Staphylococcus aureus was isolated from 5 of 8 epidural abscesses, including 2 abscesses with methicillin-resistant S. aureus. Unusual isolates were group B Streptococcus in a patient with chronic vesicouretral reflux associated with the posterior urethral valves and Aspergillus flavus in a patient with acute myelogenous leukemia. An analysis incorporating our results and a review of the English-language literature about abscesses in children and adults revealed differences related to age. Abscesses in children were more posterior in epidural location, had greater spinal column extension, and were associated with more favorable clinical outcomes than were abscesses in adults. Magnetic resonance imaging is the diagnostic procedure of choice; however, radionuclide bone scans should be considered for associated distant osteomyelitis in children. Prompt diagnosis and combined medical and surgical treatment remain the cornerstones for the prevention of adverse outcomes.

Survival of group B streptococcus type III in mononuclear phagocytes: differential regulation of bacterial killing in cord macrophages by human recombinant gamma interferon and granulocyte-macrophage colony-stimulating factor

Phagocytic and killing capacities of resident and cytokine-activated human macrophages against group B Streptococcus (GBS) type III were studied. Evidence is presented that monocyte-derived macrophages from cord and adults ingest serum-opsonized GBS but that killing of bacteria was negligible in resident cells. Treatment of adult macrophages with recombinant human gamma interferon (rhIFN-gamma; 100 U/ml) or recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF; 200 U/ml) resulted in significant increases of killing of GBS (P < 0.01 for each). The killing capacity of cord macrophages treated with rhGM-CSF was also enhanced compared to that of untreated cells (P < 0.01). However, treatment with rhIFN-gamma resulted in only a moderate increase in the capacity of cord macrophages to kill GBS (P > 0.1). These results mirrored the effect of rhIFN-gamma on candidacidal capacities of cord and adult macrophages, reported earlier from our laboratory. These data indicate differential modulation of neonatal macrophages by rhGM-CSF and rhIFN-gamma. We suggest that administration of rhGM-CSF to neonates with invasive GBS disease may enhance host resistance to these bacteria.

Occult bacteremia with group B streptococci in an outpatient setting

OBJECTIVES

We undertook this study to determine the relative frequency of occult bacteremia with group B streptococci (GBS) and to define the clinical features of infants with occult bacteremia attributable to GBS at the time of initial clinical contact.

DESIGN

The logs of the microbiology laboratory were reviewed for blood and cerebrospinal fluid isolates of GBS from 1982 to 1996. Records of patients identified with GBS were abstracted. Patients were classified as having occult bacteremia if GBS were isolated from their blood and they seemed nontoxic and had no apparent clinical or laboratory evidence of focal infection. All other patients were diagnosed with sepsis, meningitis, or nonmeningeal foci.

RESULTS

We reviewed the medical records of 147 children with GBS and identified 108 outpatients, including 47 (44%) with occult bacteremia, 42 (39%) with meningitis, 11 (10%) with nonmeningeal foci, and 8 (7%) with sepsis. Compared with patients with sepsis or focal infections, those with occult bacteremia were older (61.1 vs 39.1 days) and had slightly, although not significantly, higher white blood cell (WBC) counts (13 280 +/- 6854 vs 10 688 +/- 8574), but similar degrees of fever. Among the 47 patients with occult bacteremia, none died, as compared with 2 of 61 with serious infections, and fewer had neurologic sequelae (0/47 vs 11/61). Patients with occult bacteremia >90 days of age generally had temperatures >39 degreesC (9/11, mean 39.3 degreesC) and WBC counts >15 000/mm3 (7/10, mean 19 070/mm3), both of which differed significantly compared with those who were <90 days of age. Thirty of the 47 patients with occult bacteremia received intravenous antibiotics and recovered. One of 8 patients discharged without antibiotics and none of 8 with antibiotics developed a focal complication; 1 discharged patient was lost to follow-up.

CONCLUSIONS

Almost one-half of the children with GBS disease beyond the immediate neonatal period had occult bacteremia. Among 8 untreated patients with bacteremia, 1 developed a focal complication. Although the small proportion of children with GBS occult bacteremia who were >90 days of age usually had the risk factors of temperature >39 degrees C and WBC >15 000/mm3, as seen with occult bacteremia attributable to other organisms, the majority of the patients who were younger did not have a characteristic clinical syndrome. Prevention of sequelae in these young infants will require a low threshold for diagnosis and treatment.

Sudden increase in isolation of group B streptococci, serotype V, is not due to emergence of a new pulsed-field gel electrophoresis type

Until recently, group B streptococcus, serotype V (GBS-V), was an infrequent cause of disease. It is now recognized as a significant cause of infections in both children and adults. To determine if this increase was due to the recent introduction and spread of a single clone of GBS-V, we analyzed, by pulsed-field gel electrophoresis (PFGE), the SmaI chromosomal DNA digests of 45 bacteria: 41 isolated from human infections between 1986 and 1996 in the United States, 2 from human infections in Argentina, and 2 from naturally infected mice. Seventeen patterns were found and arbitrarily designated patterns A to Q. Pattern N constituted 24 (53%) of the isolates and was found in all of the years tested and from all surveillance areas, as well as in both isolates from Argentina, and was very similar to the GBS-V isolated from a mouse. Pattern P was found in three isolates, pattern F was found in two, and the remaining patterns were found in one isolate each. We concluded that the majority of isolates of GBS-V are of one PFGE subtype and that this subtype was predominate before the increase in disease caused by GBS-V and that GBS-V disease is caused by several different subtypes.