Group B streptococcal infection

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Streptococcus, group B, as the cause of diseases classified to other chapters
Classification and external resources
ICD-10 B95.1

Infection with Group B Streptococcus (GBS), also known as 'Streptococcus agalactiae' and more colloquially as Strep B and group B Strep, can cause serious illness and sometimes death, especially in newborn infants, the elderly, and patients with compromised immune systems.[1] Group B streptococci are also prominent veterinary pathogens, because they can cause bovine mastitis (inflammation of the udder) in dairy cows. The species name "agalactiae" meaning "no milk", alludes to this.

Streptococcus is a genus of spherical, Gram-positive bacteria of the phylum Firmicutes. Streptococcus agalactiae is a gram-positive streptococcus characterized by the presence of Group B Lancefield antigen, and so takes the name Group B Streptococcus.

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[edit] Perinatal disease

U.S. Prevention of Perinatal Group B Streptococcal Disease, CDC

GBS is a member of the normal flora of the gut and female urogenital tract, so many women are carriers of this bacterium without knowing it. GBS colonization can be chronic or intermittent.

GBS bacteria can be passed from a pregnant woman to her baby during labor, if she is a carrier of the bacteria.

[edit] Perinatal Group B Streptococcal Disease

25% of women are colonized with GBS in the vagina or rectum.[2] Since the bacteria can come and go, testing for GBS is recommended by US public health protocols at the 36 week antenatal appointment of every pregnancy. The vagina and rectum are swabbed and cultures grown in enriched culture media. In the UK, cultures are not routinely grown at 36 weeks, but rather women are treated according to their risk in labor - antibiotics are given to women whose membranes are ruptured more than 18 hours and those who have fever. In some countries[weasel words] suboptimal culture methods are used, which result in up to half of women carrying GBS when swabbed, and being given a false-negative test result.[citation needed] Treatment of GBS positive women with intravenous penicillin at the onset of labor and then again at every sixth hour reduces early neonatal infection,[3] but research has shown that treatment at least 2 hours prior to birth is also beneficial.[citation needed][clarification needed]

Where insufficient intravenous antibiotics are given before delivery, the baby may be given antibiotics immediately after birth, although evidence is inconclusive as to whether this is effective.[4] Some maternity units take a watchful approach for 24–48 hours, only giving antibiotics if the baby shows any symptoms of infection,[citation needed] or if there is laboratory evidence on CBC[clarification needed] or culture of infection. If a woman presents late in her prenatal period then there may be no time to grow cultures prior to labor, or she may present in active labor without documentation of prenatal care. In this situation, some clinicians advocate empirical antibiotic coverage of mother and baby, although most would only advocate antibiotics for the mother if other recognized risk factors were present.

[edit] Perinatal GBS disease prevention

Through collaborative efforts clinicians, researchers, professional organizations, parent advocacy groups, and the public health community developed recommendations for intrapartum prophylaxis to prevent Perinatal GBS disease. Many organizations have developed perinatal GBS disease prevention and education programs to reduce the incidence of the disease. Information about the recommendations and the prevention programs can be found in medical journals and on the internet.

[edit] References

  • Brooks, Geo F., Janet Butel, and Stephen Morse. Jawetz, Melnick, and Adelberg's Medical Microbiology, 22nd edition. 2001.
  • Gillespie, Stephen and Kathleen Bamford. Medical Microbiology at a Glance. 2000.
  1. ^ http://www.dhpe.org/infect/strepb.html
  2. ^ "Preventing Group B Strep: Are You Pregnant? Protect your baby from group B strep!" (pdf). Center for Disease Control and Prevention. 2004-02-09. http://www.cdc.gov/groupbstrep/. Retrieved on 2007-10-18. 
  3. ^ Smaill FM. "[http://mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD000115/pdf_fs.html Intrapartum antibiotics for Group B streptococcal colonisation]". Cochrane Library. http://mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD000115/pdf_fs.html. Retrieved on 2008-07-20. 
  4. ^ Woodgate P, Flenady V, Steer P. "Intramuscular penicillin for the prevention of early onset group B streptococcal infection in newborn infants". Cochrane Library. http://www.cochrane.org/reviews/en/ab003667.html. Retrieved on 2008-07-20. 

[edit] External links

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