Ed Bell, MD, neonatologist at University of Iowa Children's Hospital, talks about group B streptococcus:
What is group B strep?
Group B strep is one of the streptococcus bacteria not as well known by most people as group A strep, the one that causes strep throat.
What illnesses does group B strep cause?
The most serious disease is an infection of the newborn infant. It can cause quite serious infections of the blood stream and even meningitis. It's the most common cause of these serious problems in newborn babies.
How do people get infected with group B strep?
It normally lives in the body of many people without causing any problem. About 20 or 25 percent of women of child bearing age have the group B streptococcus living in their body, usually in the lower intestinal tract, so the babies can get it before or at the time of birth. It's directly passed from the mother's body to the baby's body, either after the rupture of the bag of waters or as the baby passes through the birth canal.
How is group B strep infection diagnosed?
Most of the time we don't bother trying to diagnose it in healthy people because it doesn't cause any problems. Now it's routine for pregnant women to be tested for group B streptococcus, and the testing is done by taking a culture of a swab from the uterine cervix to see if the bacteria are present there.
Is there any particular group that would be more at risk for group B strep infection?
Not that we know. There's some difference in the colonization rate as you go from place to place around the country. In most places where it's been studied, somewhere between 10 and 30 percent of women of child bearing age have this. It's passed from person to person with sexual contact primarily, so it is one of the lesser known diseases in that category; women contract it from their sexual partner, usually.
What complications can result from group B strep infection?
The most important infection is in newborn babies. It can also make adults ill if they have abnormal immune defenses. People who have been treated for cancer or sometimes people with diabetes can get this. But it's really the newborn baby that's the serious concern. The problem is it's not easy to eradicate it from women who carry this bacteria. The only thing we can do--and it actually works pretty well--is to give antibiotics to women who have this once they go into labor, and the antibiotics are given intravenously and that reduces the chance of the baby getting it.
Is that the only treatment for group B strep infection?
That's the main method of preventing babies from getting it. If babies are unlucky enough to get it, then we can also treat them directly with antibiotics. I should emphasize that most women who have this living in their bodies never pass it to their babies, and even if they do, the babies don't become sick. So it's less than one baby per thousand born in the U.S. that has this.
So it doesn't sound terribly common then.
It's not common but it's quite serious nonetheless. There are about 8,000 babies in the U.S. who become ill with this each year.
How can group B strep infection be prevented?
Unfortunately, we don't have a vaccine that's effective yet, but there's research going on here and other places to try and solve that aspect. Short of a vaccine, the best we can do is to test pregnant women to see if they're carrying it, then give them antibiotics when they go into labor, and then watch the babies closely after they're born to see whether they might be ill. |
