Streptococcus B
Lydia, a 27-year-old woman, is 34 weeks pregnant with her first child and is at her doctor’s appointment with her husband Paul. During their conversation, she asks her doctor to inform her about the vaginal screening test for Streptococcus B. Dr. Mansfield answers:
“Streptococcus B is a bacterium found naturally in the vagina in 10% to 30% of women (more 30% according to our research). These women are considered to be “healthy” carriers since the bacterium is not causing any problems. If these women start taking antibiotics, they will become “healthy” carriers if they ever come into contact with the bacterium again. The only time that being a carrier of streptococcus B can cause problems is when the woman is in labour, especially if the vagina membranes are torn.
“Is this a new threat like the SARS virus or the flesh-eating bacteria?” asks a concerned Lydia.
“No, we have known about this bacterium for a long time. The recommendations are new and still subject to change if research finds other clues”.
“Is that the reason we never heard about this 6 years ago when my first wife and I had a child?” asks Paul.
“That’s right. At that time, the screening test for Streptococcus B was not recommended. We knew about the bacterium, but we would only treat the women who were susceptible to getting an infection, like the ones who had already had a baby affected by Streptococcus B, the ones who had traces of Streptococcus B in their urine, the ones who started labour before the 37th week, the ones who got a fever during labour or if the vaginal membranes had been torn for over 18 hours”.
“What are today’s recommendations?” asks Lydia.
Dr. Mansfield answers with a comforting smile: “The society of obstetricians and gynaecologists of Canada recommends a vaginal culture, which consists in getting vaginal and rectal samples for every woman between her 35th and 37th week of pregnancy. It is then recommended that every woman with streptococcus B be treated with intravenous antibiotics, like Penicillin G if the patient is not allergic. This way, the mother passes the antibiotics on to the baby to protect him from the Streptococcus.
“It seems simple” says Paul. “Let’s go with the culture!”
Dr. Mansfield smiles and says: “That was the simple version of the story. Would you like to hear the longer version?”
Lydia immediately grabs her "Baby" notebook and a pen: “Go ahead! I’m ready!”
“Let’s start by the beginning”, says Dr. Mansfield with a sigh that says a lot. “First of all, you need to know that when the vaginal culture was not a routine procedure with pregnant women, we didn’t have 30% of babies infected with Streptococcus B. A very low percentage of babies born from mothers with Streptococcus B actually caught it”.
“What can happen if a baby catches Streptococcus B?” asks Paul.
“A septicaemia (blood infection), pneumonia, meningitis… etc.” answers Dr. Mansfield.
“So, let’s go with the culture”, concludes Paul. “I don’t want my baby to have those problems. If this guarantees that our child won’t have an infection…”
“It doesn’t necessarily guarantee it. There are many cases of women who got a negative culture and didn’t receive antibiotics, and yet their baby developed a Streptococcus B septicaemia”.
“Ok, but if the antibiotics are not harmful, then why not give them as a preventive measure?”
“Here’s where I'm reluctant”, admits Dr. Mansfield. “You have all heard about the excessive use of antibiotics and the harmful consequences they could have on the development of the “super bacteria”, a bacteria that does not respond to any antibiotics. Furthermore, we currently don’t have the enough retrospect to know the influence antibiotics have on babies, but carefulness is always best.”
“Don’t tell me about it. My uncle is in the hospital and suffers from Hard Clostridium” adds Lydia with a severe look on her face. “It’s very serious, and except the good treatments that are keeping him going, none of the antibiotics are working. The whole family is hoping he gets better.”
“Hard Clostridium is a new type of bacteria that has become resistant to antibiotics. There are many other types, like E Coli, that affect young children. As a matter of fact, the amoxicillin that was once used to prevent the Streptococcus B infections is no longer our first choice because a resisting bacterium have developed.”
“So it may not be ideal to expose an unborn baby to antibiotics as useful as Penicillin…” mumbles Paul.
“Exactly”, answers Dr. Mansfield. “You will quickly realize that today’s medicine is far from having the perfect solution for every problem. That’s something I understood well before finishing med school. I didn’t mention that the mother could also be allergic to penicillin, and if that’s the case, she could end up with a severe allergic reaction, which means an anaphylactic shock.
“Phew” says Paul in a sigh of relief.
“And”, continues the doctor, “for the antibiotics to be effective in the baby’s placenta, the mother must have received her dose of penicillin four hours before delivering”.
“What would they do with women who deliver in less than two hours?” asks Lydia.
“You can always refuse the vaginal culture and decide to go ahead with treatment if some of the risk factors explained before are present. If a woman hasn’t received antibiotics and we know she is positive to Streptococcus B, the baby will be considered “at risk” and will be monitored closely by the paediatrician who may decide to do blood tests and a hemoculture. While waiting for the results, which can take up to 48 hours, the paediatrician could decide to give the baby intravenous antibiotics if he shows signs of infection. The doctor can’t take that chance”.
“Can you sum up the facts, Dr. Mansfield?” asks Lydia while taking notes.
Dr. Mansfield smiles and starts:
- Almost 30% of women carry the Streptococcus B vaginal virus.
- The recommendations state that treatment should be given during labour to any woman who has a positive screening test.
- Some women had a negative screening test and their babies developed a Streptococcus B infection. Treating every woman with a positive screening test does not prevent all cases of infection.
- I completely agree with treating patients depending on the risk factors talked about before… Knowing it doesn’t prevent all cases either.
- Statistics show that we need to treat 200 women to prevent one case of baby’s Streptococcus B infection, because the infection is relatively rare. We are not statistics, and when a baby is infected, it’s always a tragic event.
- A warning has been put out in the medical society to prevent the excessive use of antibiotics, because it is now more common to see really resistant bacteria, therefore, potentially very dangerous.
“Many articles exist on the subject. You must be careful because many of them are distorted and dramatize the situation, and others seem to be opposed to everything without actually taking the facts into account."
