Jan 6, 2016

Group B Streptococcus Infection

Since the early 1970’s, Group B Streptococcus (GBS) have been identified as the number one cause of life threatening infections in newborn babies. Group B Streptococcus should not be confused with Group A Streptococcus which causes throat infection and may lead to Rh fever and RHD.

Streptococcus group B is normally found in the vagina and lower intestine of 15% to 40% of all healthy, adult women. Those women who test positive for GBS are said to be colonized. Neonates acquire the infection as a vertical transmission from the maternal genital tract in utero or at delivery

Diseases in neonates can manifest in two forms. Early onset and late onset. Early sepsis with GBS is often observed within 24 hr of delivery but it can manifest as late as 7 days after birth. Meningitis, Pneumonia and bacteremia is common etiology with GBS. Premature babies are more susceptible to GBS infection than full term babies. Performance of a cesarean section will not eliminate the risk of infection.

An estimated 12,000 infants in the United States become infected with GBS each year resulting in death of an estimated 2,000 infants, while leaving many others mentally and/or physically handicapped.

GBS infections are more common than other illnesses for which pregnant women are screened, such as rubella, Down’s syndrome and spina bifida. Yet, GBS remains generally unknown to the public.

Fortunately, there is testing and a preventative treatment available that can help prevent many of these infections


“Do All Women Carry GBS?”

If 1000 women, regardless of race or socioeconomic status, had a vaginal culture taken, 150-350 would test positive for GBS. Because GBS usually does not cause problems for the adult female, most women carry it and do not know it. Yet, GBS can cause serious illness in babies born to women who carry the bacteria.

“Is GBS a Sexually Transmitted Disease?”

Since GBS is normally found in the vagina and/or rectum of colonized women, one way it can colonize another individual is through sexual contact. However, this bacteria usually does not cause genital symptoms or discomfort and is generally not linked with increased sexual activity. Therefore GBS is not considered to be a sexually transmitted disease.

“How Common Are GBS Infections?”

Out of every 1000 births, three babies will become ill with GBS. Why only certain infants fall victim to this infection is not completely known. An estimated 12,000 babies will suffer from GBS infections each year.

“What Complications Does GBS Cause?”

Most often, GBS colonizes the baby during labor either by traveling upward from the mother’s vagina into the uterus, or as the infant passes through the birth canal.

“When is GBS a Threat?”

GBS can be present in a woman’s first pregnancy, or in following pregnancies. The bacteria can be a threat both during pregnancy and at the time of delivery. It has
been shown that women who carry large amounts of the bacteria are at greatest risk of having a baby infected with GBS. Also, the occurrence of GBS infections are increased in certain high risk situations.


  • When labor is premature;
  • When there is premature rupture of the membranes;
  • When there is prolonged rupture of membranes (>12 hours) before the baby is born;
  • If the mother has a fever (>100.4 F) before or during labor;
  • Women who have a history of GBS in previous births.

“Can GBS Infections Be Prevented?”

Yes. There is a fast and effective treatment for many situations. Medical research indicates that giving antibiotics to the mother during labor can greatly reduce the frequency of GBS infection in the baby immediately after birth or during the first week of life.

Treating the mother with oral antibiotics during the pregnancy may decrease the amount of GBS for a short time, but it will not eliminate the bacteria completely and will leave the baby unprotected at birth. Also, waiting to treat the baby with antibiotics after birth is often too late to prevent illness.

Carriers of GBS

Some doctors routinely screen for GBS by doing cultures on their patients during pregnancy. These cultures must be taken from the lower vagina and rectum, not the cervix.

Women who are found to carry the bacteria can then be treated as potential GBS risk patients. But, just like any other bacteria in the human body, GBS can be present in small amounts on one day which would result in a negative culture. Therefore, one negative culture result does not guarantee that you will be negative on the day of delivery. .Current studies indicate that a lower vaginal AND rectal culture done late in pregnancy is more than 93% accurate in detecting who will not carry the bacteria at delivery.)

At LPL following tests are available

  • Streptococcus Group B antigen detection.
  • Culture of vaginal and rectal swabs.

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