According to the U.S. Centers for Disease Control and Prevention, group B strep is one of the most common life-threatening infections and is still one of the leading causes of blood infection and meningitis in newborns. Jon Klein, MD, medical director of the Neonatal Intensive Care Unit at University of Iowa Children's Hospital, talks about Group B strep:
What is group B strep or GBS?
This is a bacterial infection that commonly occurs within the first 24 hours after delivery, to up to one week in babies. This bacterial infection can lead to respiratory distress, pneumonia, shock, apnea, and meningitis in babies.
How common is GBS and what are the symptoms in pregnant women?
GBS is actually very common. Up to 15 to 40 percent of all pregnant women are colonized with GBS. It is a very common inhabitant of the GI and genitourinary tract in women. The major problem is that many women can be colonized with the bacteria but do not have any symptoms. A few do have symptoms, such as urinary tract infection and chorioamnionitis, which is an infection of the fluids surrounding the baby.
Is there a test all pregnant women should have to detect group B strep?
The best test is a culture from the regions of the birth canal, and this culture usually is done between 35 and 37 weeks of gestation. If we know this culture is positive, we can help prevent transmission of this bacteria through the birth canal to the baby.
If a woman has GBS and becomes pregnant, how might it affect or infect her baby?
The major problem is that as the baby goes through the birth canal or if the membranes rupture prior to delivery, the bacteria can ascend into the baby's blood stream and cause a very rapid and fulminant infection within often less than 24 hours after delivery.
How can a pregnant woman protect her baby from GBS during pregnancy?
There are two major ways. One is if we know that the culture is positive. The other is if the mother has risk factors at the time of delivery, such as premature delivery, ruptured membranes for more than 18 hours, or a fever above 100.4 F, the obstetricians give the mother what we call intrapartum chemoprophylaxis, primarily antibiotics—either penicillin or ampicillin—to prevent transmission. Since the use of intrapartum chemoprophylaxis started in the United States, the rate of transmission has dropped by more than 80 percent, from about four per thousand babies, to 0.3 per thousand.
If a woman with GBS is pregnant, are there special precautions that should be taken during labor and delivery?
Recognize if the mother has risk factors, the mother previously has not been shown to have a positive group B culture, and the pediatricians to be aware that this mother has risk factors or is colonized with group B strep. That allows us to start the baby on antibiotics if there has not been adequate time for the mother to be treated. Even if there's been adequate time for the mother to be treated, this allows us to watch these babies carefully for up to 48 hours and to screen them for the possibility of infection.
Are there preventive measures to take with healthy or premature babies to prevent GBS?
The best measure to take is have active obstetrical service that examines a mother's history and says:
- Did this mother have a previous infant with group B strep?
- Does the mom have a urinary tract infection with group B strep?
- Did she have a positive group B strep culture from the birth canal?
- Did she have any risk factors that put the baby at risk?
Once we know these things, the mother can then be treated prior to delivery, and if the treatment has taken place for more than four hours, the risk of the baby getting the disease is very low. If it's been less than four hours, that gives us the information that we need to screen this baby very soon after birth and get on top of any signs of infection.
After a healthy baby is born, are they still at risk to develop group B strep?
Yes. There's something also called late-onset group B strep which can occur anywhere from seven days after birth to up to three months after birth. And in these cases the intrapartum chemoprophylaxis isn't as effective, so it's important that if a baby less than three months of age is developing fever or any signs of infection, trouble breathing—that the parents bring him to a physician as soon as possible. |
