Group B streptococcal infection overview: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 9: Line 9:


==Historical Perspective==
==Historical Perspective==
In the 1970s, the [[bacterium]] group B Streptococcus (GBS) emerged as the leading infectious cause of early neonatal [[morbidity]] and [[mortality]] in the United States.<ref name="pmid1105496">{{cite journal| author=Chattopadhyay B| title=Fatal neonatal meningitis due to group B streptococci. | journal=Postgrad Med J | year= 1975 | volume= 51 | issue= 594 | pages= 240-3 | pmid=1105496 | doi= | pmc=PMC2495958 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1105496  }} </ref><ref name="pmid4572746">{{cite journal| author=McCracken GH| title=Group B streptococci: the new challenge in neonatal infections. | journal=J Pediatr | year= 1973 | volume= 82 | issue= 4 | pages= 703-6 | pmid=4572746 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=4572746  }} </ref><ref name="pmid4572747">{{cite journal| author=Franciosi RA, Knostman JD, Zimmerman RA| title=Group B streptococcal neonatal and infant infections. | journal=J Pediatr | year= 1973 | volume= 82 | issue= 4 | pages= 707-18 | pmid=4572747 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=4572747  }} </ref><ref name="pmid4572748">{{cite journal| author=Barton LL, Feigin RD, Lins R| title=Group B beta hemolytic streptococcal meningitis in infants. | journal=J Pediatr | year= 1973 | volume= 82 | issue= 4 | pages= 719-23 | pmid=4572748 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=4572748  }} </ref>  Beginning in the mid 1980s, clinical trials and well-designed observational studies demonstrated that administering intravenous [[antibiotic]]s during [[labor]] to women at risk for transmitting GBS to their newborns could prevent invasive disease in the first week of life (i.e., early-onset disease).<ref name="pmid7039316">{{cite journal| author=Allardice JG, Baskett TF, Seshia MM, Bowman N, Malazdrewicz R| title=Perinatal group B streptococcal colonization and infection. | journal=Am J Obstet Gynecol | year= 1982 | volume= 142 | issue= 6 Pt 1 | pages= 617-20 | pmid=7039316 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=7039316  }} </ref><ref name="pmid3520319">{{cite journal| author=Boyer KM, Gotoff SP| title=Prevention of early-onset neonatal group B streptococcal disease with selective intrapartum chemoprophylaxis. | journal=N Engl J Med | year= 1986 | volume= 314 | issue= 26 | pages= 1665-9 | pmid=3520319 | doi=10.1056/NEJM198606263142603 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3520319  }} </ref><ref name="pmid3514659">{{cite journal| author=Lim DV, Morales WJ, Walsh AF, Kazanis D| title=Reduction of morbidity and mortality rates for neonatal group B streptococcal disease through early diagnosis and chemoprophylaxis. | journal=J Clin Microbiol | year= 1986 | volume= 23 | issue= 3 | pages= 489-92 | pmid=3514659 | doi= | pmc=PMC268680 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3514659  }} </ref><ref name="pmid2494620">{{cite journal| author=Tuppurainen N, Hallman M| title=Prevention of neonatal group B streptococcal disease: intrapartum detection and chemoprophylaxis of heavily colonized parturients. | journal=Obstet Gynecol | year= 1989 | volume= 73 | issue= 4 | pages= 583-7 | pmid=2494620 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2494620  }} </ref><ref name="pmid1930031">{{cite journal| author=Garland SM, Fliegner JR| title=Group B streptococcus (GBS) and neonatal infections: the case for intrapartum chemoprophylaxis. | journal=Aust N Z J Obstet Gynaecol | year= 1991 | volume= 31 | issue= 2 | pages= 119-22 | pmid=1930031 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1930031  }} </ref>  As a result of the collaborative efforts of clinicians, researchers, professional organizations, parent advocacy groups, and the public health community in the 1990s, recommendations for intrapartum [[prophylaxis]] to prevent perinatal GBS disease were issued in 1996 by the American College of Obstetricians and Gynecologists (ACOG)<ref name=ACOG>American College of Obstetricians and Gynecologists. ACOG committee opinion. Prevention of early-onset group B streptococcal disease in newborns. Number 173,June 1996. Committee on Obstetric Practice. American College of Obstetrics and Gynecologists. Int J Gynaecol Obstet 1996;54:197--205.</ref> and CDC<ref name=CDC>CDC. Prevention of perinatal group B streptococcal disease: a public health perspective. MMWR 1996;45(No. RR-7).[http://www.cdc.gov/mmwr/preview/mmwrhtml/00043277.htm]</ref> and in 1997 by the American Academy of Pediatrics (AAP).<ref name=AAP>American Academy of Pediatrics. Revised guidelines for prevention of early-onset group B streptococcal (GBS) infection. American Academy of Pediatrics Committee on Infectious Diseases and Committee on Fetus and Newborn. Pediatrics 1997;99:489--96.</ref> Revised guidelines for the prevention of early-onset GBS disease issued in 2002 recommended universal culture-based screening of all pregnant women at 35-37 weeks gestation to optimize the identification of women who should receive intrapartum [[antibiotic]] prophylaxis.<ref name= CDC2002>CDC. Prevention of perinatal group B streptococcal disease: revised guidelines from CDC. MMWR 2002;51(No. RR-11).[http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5111a1.htm]</ref>  The most recent CDC guidelines were published in 2010.<ref name=CDCMMWR>Verani J.R., McGee L, and Schrag S.J. Prevention of Perinatal Group B Streptococcal Disease. Revised Guidelines from CDC, 2010.[http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5910a1.htm?s_cid=rr5910a1_w CDC.gov]</ref>


==Classification==
==Classification==
Group B streptococcal (GBS) infection can be classified into three main categories depending on the type of affected subjects.  GBS infection can occur in [[pregnant]] women, [[neonate]]s, or non-pregnant adults mainly the elderly.<ref name="pmid16107984">{{cite journal| author=Edwards MS, Baker CJ| title=Group B streptococcal infections in elderly adults. | journal=Clin Infect Dis | year= 2005 | volume= 41 | issue= 6 | pages= 839-47 | pmid=16107984 | doi=10.1086/432804 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16107984  }} </ref>  Neonatal GBS infection can be further classified into early-onset or late-onset depending on the timing of the onset of the symptoms.  Infections in newborns occurring within the first week of life are designated as early-onset disease, whereas late-onset infections occur in infants aged >1 week, with most infections evident during the first 3 months of life. <ref name=CDCMMWR>Verani J.R., McGee L, and Schrag S.J. Prevention of Perinatal Group B Streptococcal Disease. Revised Guidelines from CDC, 2010.[http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5910a1.htm?s_cid=rr5910a1_w CDC.gov]</ref>


==Pathophysiology==
==Pathophysiology==
The [[gastrointestinal tract]] serves as the primary reservoir for Group B Streptococcus (GBS) and is the likely source of [[vagina]]l colonization.  Early-onset neonatal infections are acquired vertically through exposure to GBS from the [[vagina]] of a colonized woman.  GBS is characterized by its ability to adhere to [[epithelial]] surfaces, such as the [[vagina]], [[placenta]]l membranes, [[blood brain barrier]], and [[respiratory tract]].  GBS can penetrate the host cell barriers and evade the host's [[immune response]].  The polysaccharide antiphagocytic capsule is this bacterium's main [[virulence factor]].


==Causes==
==Causes==
Group B Streptococcus (GBS) disease is caused by the infection with the bacterium GBS which is a beta hemolytic [[gram-positive]] [[streptococcus]] characterized by the presence of group B [[Rebecca Lancefield|Lancefield]] antigen. GBS displays beta-hemolysis when cultured on a blood agar plate and produces zones of hemolysis that are only slightly larger than the colonies themselves. The species other name S. agalactiae, where "agalactiae" means "no milk", alludes to this.  GBS hydrolyzes sodium hippurate and gives a positive response in the [[CAMP test]]. GBS is also sensitive to [[bile]] and will lyse in its presence.  GBS is a species of the normal flora of the gut and female urogenital tract.  The polysaccharide antiphagocytic capsule is this bacterium's main [[Virulence|virulence factor]].


==Differential Diagnosis==
==Differential Diagnosis==
Group B Streptococcus ([[GBS]]) infection causes a wide variety of clinical presentations depending on the type of the affected subjects; therefore, the differential diagnosis of GBS infection varies based on the age of the patient and their health condition.  Early-onset GBS infection in neonates might lead to [[pneumonia]], [[meningitis]], or [[sepsis]] and it must be differentiated from other types of infectious agents in this category of patients.


==Epidemiology and Demographics==
==Epidemiology and Demographics==
Group B Streptococcus (GBS) causes invasive disease primarily in infants, pregnant or postpartum women, and older adults, with the highest incidence among young infants.<ref name="pmid18460666">{{cite journal| author=Phares CR, Lynfield R, Farley MM, Mohle-Boetani J, Harrison LH, Petit S et al.| title=Epidemiology of invasive group B streptococcal disease in the United States, 1999-2005. | journal=JAMA | year= 2008 | volume= 299 | issue= 17 | pages= 2056-65 | pmid=18460666 | doi=10.1001/jama.299.17.2056 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18460666  }} </ref>  Before active prevention was initiated, an estimated 7,500 cases of neonatal GBS disease occurred annually in the United States.<ref name="pmid1470102">{{cite journal| author=Zangwill KM, Schuchat A, Wenger JD| title=Group B streptococcal disease in the United States, 1990: report from a multistate active surveillance system. | journal=MMWR CDC Surveill Summ | year= 1992 | volume= 41 | issue= 6 | pages= 25-32 | pmid=1470102 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1470102  }} </ref> Striking declines in disease incidence coincided with increased prevention activities in the 1990s,<ref name="pmid10620644">{{cite journal| author=Schrag SJ, Zywicki S, Farley MM, Reingold AL, Harrison LH, Lefkowitz LB et al.| title=Group B streptococcal disease in the era of intrapartum antibiotic prophylaxis. | journal=N Engl J Med | year= 2000 | volume= 342 | issue= 1 | pages= 15-20 | pmid=10620644 | doi=10.1056/NEJM200001063420103 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10620644  }} </ref> and a further reduction occurred following the issuance of the recommendation for universal screening in 2002.<ref name=CDC2007>CDC. Perinatal group B streptococcal disease after universal screening recommendations---United States, 2003--2005. MMWR 2007;56:701--5.[http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5628a1.htm]</ref>  However, GBS disease remains the leading infectious cause of morbidity and mortality among newborns in the United States.<ref name="pmid18460666">{{cite journal| author=Phares CR, Lynfield R, Farley MM, Mohle-Boetani J, Harrison LH, Petit S et al.| title=Epidemiology of invasive group B streptococcal disease in the United States, 1999-2005. | journal=JAMA | year= 2008 | volume= 299 | issue= 17 | pages= 2056-65 | pmid=18460666 | doi=10.1001/jama.299.17.2056 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18460666  }} </ref><ref name=CDC2009>CDC. Trends in perinatal group B streptococcal disease---United States, 2000--2006. MMWR 2009;58:109--12.[http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5805a2.htm]</ref>  The continued burden of disease and newly available data relevant to early-onset GBS disease prevention from the fields of epidemiology, obstetrics, neonatology, microbiology, molecular biology, and pharmacology prompted revision of the guidelines for early-onset GBS disease prevention.<ref name=CDCMMWR>Verani J.R., McGee L, and Schrag S.J. Prevention of Perinatal Group B Streptococcal Disease. Revised Guidelines from CDC, 2010.[http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5910a1.htm?s_cid=rr5910a1_w CDC.gov]</ref>


==Risk Factors==
==Risk Factors==
Maternal intrapartum GBS colonization is the primary risk factor for early-onset disease in infants.  Additional risk factors for early-onset disease in infants include [[gestational age]] < 37 completed weeks, longer duration of membrane rupture, intra-[[amniotic fluid|amniotic]] infection, young maternal age, and black race.<ref name=CDCMMWR>Verani J.R., McGee L, and Schrag S.J. Prevention of Perinatal Group B Streptococcal Disease. Revised Guidelines from CDC, 2010.[http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5910a1.htm?s_cid=rr5910a1_w CDC.gov]</ref>


==Screening==
==Screening==
The Center of Disease Control and Prevention ([[CDC]])'s screening guidelines for Group B streptococcal (GBS) infection recommend universal culture-based screening for '''all pregnant women''' for vaginal and rectal GBS colonization in order to determine which women should receive intrapartum GBS chemoprophylaxis. CDC recommended that women with unknown GBS colonization status at the time of delivery be managed according to the presence of intrapartum risk factors.  [[CDC]]'s guidelines recommend screening for '''vaginal''' and '''rectal''' GBS colonization at '''35-37 weeks' gestation'''.  Swabbing both the lower [[vagina]] and [[rectum]] (through the [[anal sphincter]]) increases the culture yield substantially compared with sampling the [[cervix]] or the vagina without also swabbing the rectum.<ref name=CDCMMWR>Verani J.R., McGee L, and Schrag S.J. Prevention of Perinatal Group B Streptococcal Disease. Revised Guidelines from CDC, 2010.[http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5910a1.htm?s_cid=rr5910a1_w CDC.gov]</ref>  Routine screening for asymptomatic [[bacteriuria]] is recommended in pregnant women, and laboratories should screen urine culture specimens for the presence of GBS in concentrations of 104 colony-forming units (cfu)/ml or greater.<ref name=CDCMMWR>Verani J.R., McGee L, and Schrag S.J. Prevention of Perinatal Group B Streptococcal Disease. Revised Guidelines from CDC, 2010.[http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5910a1.htm?s_cid=rr5910a1_w CDC.gov]</ref>


==Natural History, Complications and Prognosis==
==Natural History, Complications and Prognosis==
Group B Streptococcus (GBS) is the leading infectious cause of [[morbidity]] and mortality among infants in the United States, particularly among preterm neonates.<ref name="pmid4608888">{{cite journal| author=Baker CJ, Barrett FF| title=Group B streptococcal infections in infants. The importance of the various serotypes. | journal=JAMA | year= 1974 | volume= 230 | issue= 8 | pages= 1158-60 | pmid=4608888 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=4608888  }} </ref><ref name="pmid18460666">{{cite journal| author=Phares CR, Lynfield R, Farley MM, Mohle-Boetani J, Harrison LH, Petit S et al.| title=Epidemiology of invasive group B streptococcal disease in the United States, 1999-2005. | journal=JAMA | year= 2008 | volume= 299 | issue= 17 | pages= 2056-65 | pmid=18460666 | doi=10.1001/jama.299.17.2056 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18460666  }} </ref><ref name="pmid10620644">{{cite journal| author=Schrag SJ, Zywicki S, Farley MM, Reingold AL, Harrison LH, Lefkowitz LB et al.| title=Group B streptococcal disease in the era of intrapartum antibiotic prophylaxis. | journal=N Engl J Med | year= 2000 | volume= 342 | issue= 1 | pages= 15-20 | pmid=10620644 | doi=10.1056/NEJM200001063420103 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10620644  }} </ref> Most newborns with early-onset disease have symptoms on the day of birth. Babies who develop late-onset disease may appear healthy at birth and develop symptoms of GBS disease after the first week of life.


==Diagnosis==
==Diagnosis==

Revision as of 15:09, 21 August 2014

Group B Streptococcal Infection Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Group B Streptococcal Infection from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

Treatment

Medical Therapy

Primary Prevention

Secondary Prevention

Future or Investigational Therapies

Case Studies

Case #1

Group B streptococcal infection overview On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Group B streptococcal infection overview

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Group B streptococcal infection overview

CDC on Group B streptococcal infection overview

Group B streptococcal infection overview in the news

Blogs on Group B streptococcal infection overview

Directions to Hospitals Treating Group B streptococcal infection

Risk calculators and risk factors for Group B streptococcal infection overview

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [5]; Associate Editor(s)-in-Chief: Rim Halaby, M.D. [6]

Overview

Despite substantial progress in prevention of perinatal group B streptococcal (GBS) disease since the 1990s, GBS remains the leading cause of early-onset neonatal sepsis in the United States. Universal screening at 35--37 weeks' gestation for maternal GBS colonization and use of intrapartum antibiotic prophylaxis has resulted in substantial reductions in the burden of early-onset GBS disease among newborns. Although early-onset GBS disease has become relatively uncommon in recent years, the rates of maternal GBS colonization (and therefore the risk for early-onset GBS disease in the absence of intrapartum antibiotic prophylaxis) remain unchanged since the 1970s. Continued efforts are needed to sustain and improve on the progress achieved in the prevention of GBS disease. There also is a need to monitor for potential adverse consequences of intrapartum antibiotic prophylaxis (e.g., emergence of bacterial antimicrobial resistance or increased incidence or severity of non-GBS neonatal pathogens). In the absence of a licensed GBS vaccine, universal screening and intrapartum antibiotic prophylaxis continue to be the cornerstones of early-onset GBS disease prevention.

Historical Perspective

In the 1970s, the bacterium group B Streptococcus (GBS) emerged as the leading infectious cause of early neonatal morbidity and mortality in the United States.[1][2][3][4] Beginning in the mid 1980s, clinical trials and well-designed observational studies demonstrated that administering intravenous antibiotics during labor to women at risk for transmitting GBS to their newborns could prevent invasive disease in the first week of life (i.e., early-onset disease).[5][6][7][8][9] As a result of the collaborative efforts of clinicians, researchers, professional organizations, parent advocacy groups, and the public health community in the 1990s, recommendations for intrapartum prophylaxis to prevent perinatal GBS disease were issued in 1996 by the American College of Obstetricians and Gynecologists (ACOG)[10] and CDC[11] and in 1997 by the American Academy of Pediatrics (AAP).[12] Revised guidelines for the prevention of early-onset GBS disease issued in 2002 recommended universal culture-based screening of all pregnant women at 35-37 weeks gestation to optimize the identification of women who should receive intrapartum antibiotic prophylaxis.[13] The most recent CDC guidelines were published in 2010.[14]

Classification

Group B streptococcal (GBS) infection can be classified into three main categories depending on the type of affected subjects. GBS infection can occur in pregnant women, neonates, or non-pregnant adults mainly the elderly.[15] Neonatal GBS infection can be further classified into early-onset or late-onset depending on the timing of the onset of the symptoms. Infections in newborns occurring within the first week of life are designated as early-onset disease, whereas late-onset infections occur in infants aged >1 week, with most infections evident during the first 3 months of life. [14]

Pathophysiology

The gastrointestinal tract serves as the primary reservoir for Group B Streptococcus (GBS) and is the likely source of vaginal colonization. Early-onset neonatal infections are acquired vertically through exposure to GBS from the vagina of a colonized woman. GBS is characterized by its ability to adhere to epithelial surfaces, such as the vagina, placental membranes, blood brain barrier, and respiratory tract. GBS can penetrate the host cell barriers and evade the host's immune response. The polysaccharide antiphagocytic capsule is this bacterium's main virulence factor.

Causes

Group B Streptococcus (GBS) disease is caused by the infection with the bacterium GBS which is a beta hemolytic gram-positive streptococcus characterized by the presence of group B Lancefield antigen. GBS displays beta-hemolysis when cultured on a blood agar plate and produces zones of hemolysis that are only slightly larger than the colonies themselves. The species other name S. agalactiae, where "agalactiae" means "no milk", alludes to this. GBS hydrolyzes sodium hippurate and gives a positive response in the CAMP test. GBS is also sensitive to bile and will lyse in its presence. GBS is a species of the normal flora of the gut and female urogenital tract. The polysaccharide antiphagocytic capsule is this bacterium's main virulence factor.

Differential Diagnosis

Group B Streptococcus (GBS) infection causes a wide variety of clinical presentations depending on the type of the affected subjects; therefore, the differential diagnosis of GBS infection varies based on the age of the patient and their health condition. Early-onset GBS infection in neonates might lead to pneumonia, meningitis, or sepsis and it must be differentiated from other types of infectious agents in this category of patients.

Epidemiology and Demographics

Group B Streptococcus (GBS) causes invasive disease primarily in infants, pregnant or postpartum women, and older adults, with the highest incidence among young infants.[16] Before active prevention was initiated, an estimated 7,500 cases of neonatal GBS disease occurred annually in the United States.[17] Striking declines in disease incidence coincided with increased prevention activities in the 1990s,[18] and a further reduction occurred following the issuance of the recommendation for universal screening in 2002.[19] However, GBS disease remains the leading infectious cause of morbidity and mortality among newborns in the United States.[16][20] The continued burden of disease and newly available data relevant to early-onset GBS disease prevention from the fields of epidemiology, obstetrics, neonatology, microbiology, molecular biology, and pharmacology prompted revision of the guidelines for early-onset GBS disease prevention.[14]

Risk Factors

Maternal intrapartum GBS colonization is the primary risk factor for early-onset disease in infants. Additional risk factors for early-onset disease in infants include gestational age < 37 completed weeks, longer duration of membrane rupture, intra-amniotic infection, young maternal age, and black race.[14]

Screening

The Center of Disease Control and Prevention (CDC)'s screening guidelines for Group B streptococcal (GBS) infection recommend universal culture-based screening for all pregnant women for vaginal and rectal GBS colonization in order to determine which women should receive intrapartum GBS chemoprophylaxis. CDC recommended that women with unknown GBS colonization status at the time of delivery be managed according to the presence of intrapartum risk factors. CDC's guidelines recommend screening for vaginal and rectal GBS colonization at 35-37 weeks' gestation. Swabbing both the lower vagina and rectum (through the anal sphincter) increases the culture yield substantially compared with sampling the cervix or the vagina without also swabbing the rectum.[14] Routine screening for asymptomatic bacteriuria is recommended in pregnant women, and laboratories should screen urine culture specimens for the presence of GBS in concentrations of 104 colony-forming units (cfu)/ml or greater.[14]

Natural History, Complications and Prognosis

Group B Streptococcus (GBS) is the leading infectious cause of morbidity and mortality among infants in the United States, particularly among preterm neonates.[21][16][18] Most newborns with early-onset disease have symptoms on the day of birth. Babies who develop late-onset disease may appear healthy at birth and develop symptoms of GBS disease after the first week of life.

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

Treatment

Medical Therapy

Primary Prevention

Secondary Prevention

Future or Investigational Therapies

References

  1. Chattopadhyay B (1975). "Fatal neonatal meningitis due to group B streptococci". Postgrad Med J. 51 (594): 240–3. PMC 2495958. PMID 1105496.
  2. McCracken GH (1973). "Group B streptococci: the new challenge in neonatal infections". J Pediatr. 82 (4): 703–6. PMID 4572746.
  3. Franciosi RA, Knostman JD, Zimmerman RA (1973). "Group B streptococcal neonatal and infant infections". J Pediatr. 82 (4): 707–18. PMID 4572747.
  4. Barton LL, Feigin RD, Lins R (1973). "Group B beta hemolytic streptococcal meningitis in infants". J Pediatr. 82 (4): 719–23. PMID 4572748.
  5. Allardice JG, Baskett TF, Seshia MM, Bowman N, Malazdrewicz R (1982). "Perinatal group B streptococcal colonization and infection". Am J Obstet Gynecol. 142 (6 Pt 1): 617–20. PMID 7039316.
  6. Boyer KM, Gotoff SP (1986). "Prevention of early-onset neonatal group B streptococcal disease with selective intrapartum chemoprophylaxis". N Engl J Med. 314 (26): 1665–9. doi:10.1056/NEJM198606263142603. PMID 3520319.
  7. Lim DV, Morales WJ, Walsh AF, Kazanis D (1986). "Reduction of morbidity and mortality rates for neonatal group B streptococcal disease through early diagnosis and chemoprophylaxis". J Clin Microbiol. 23 (3): 489–92. PMC 268680. PMID 3514659.
  8. Tuppurainen N, Hallman M (1989). "Prevention of neonatal group B streptococcal disease: intrapartum detection and chemoprophylaxis of heavily colonized parturients". Obstet Gynecol. 73 (4): 583–7. PMID 2494620.
  9. Garland SM, Fliegner JR (1991). "Group B streptococcus (GBS) and neonatal infections: the case for intrapartum chemoprophylaxis". Aust N Z J Obstet Gynaecol. 31 (2): 119–22. PMID 1930031.
  10. American College of Obstetricians and Gynecologists. ACOG committee opinion. Prevention of early-onset group B streptococcal disease in newborns. Number 173,June 1996. Committee on Obstetric Practice. American College of Obstetrics and Gynecologists. Int J Gynaecol Obstet 1996;54:197--205.
  11. CDC. Prevention of perinatal group B streptococcal disease: a public health perspective. MMWR 1996;45(No. RR-7).[1]
  12. American Academy of Pediatrics. Revised guidelines for prevention of early-onset group B streptococcal (GBS) infection. American Academy of Pediatrics Committee on Infectious Diseases and Committee on Fetus and Newborn. Pediatrics 1997;99:489--96.
  13. CDC. Prevention of perinatal group B streptococcal disease: revised guidelines from CDC. MMWR 2002;51(No. RR-11).[2]
  14. 14.0 14.1 14.2 14.3 14.4 14.5 Verani J.R., McGee L, and Schrag S.J. Prevention of Perinatal Group B Streptococcal Disease. Revised Guidelines from CDC, 2010.CDC.gov
  15. Edwards MS, Baker CJ (2005). "Group B streptococcal infections in elderly adults". Clin Infect Dis. 41 (6): 839–47. doi:10.1086/432804. PMID 16107984.
  16. 16.0 16.1 16.2 Phares CR, Lynfield R, Farley MM, Mohle-Boetani J, Harrison LH, Petit S; et al. (2008). "Epidemiology of invasive group B streptococcal disease in the United States, 1999-2005". JAMA. 299 (17): 2056–65. doi:10.1001/jama.299.17.2056. PMID 18460666.
  17. Zangwill KM, Schuchat A, Wenger JD (1992). "Group B streptococcal disease in the United States, 1990: report from a multistate active surveillance system". MMWR CDC Surveill Summ. 41 (6): 25–32. PMID 1470102.
  18. 18.0 18.1 Schrag SJ, Zywicki S, Farley MM, Reingold AL, Harrison LH, Lefkowitz LB; et al. (2000). "Group B streptococcal disease in the era of intrapartum antibiotic prophylaxis". N Engl J Med. 342 (1): 15–20. doi:10.1056/NEJM200001063420103. PMID 10620644.
  19. CDC. Perinatal group B streptococcal disease after universal screening recommendations---United States, 2003--2005. MMWR 2007;56:701--5.[3]
  20. CDC. Trends in perinatal group B streptococcal disease---United States, 2000--2006. MMWR 2009;58:109--12.[4]
  21. Baker CJ, Barrett FF (1974). "Group B streptococcal infections in infants. The importance of the various serotypes". JAMA. 230 (8): 1158–60. PMID 4608888.

Template:Bacterial diseases


Template:WikiDoc Sources