Submitted by Terry Masek, SPHR, Human Resources Officer, Metropolitan Medical Laboratory, PLC, and Cindy Anderson MT(ASCP) SM, Infectious Disease Laboratory Coordinator
Group B Strep (GBS) is the most common cause of life-threatening infections in newborns. GBS, also known as baby strep, is bacteria which can pass from a mother to her baby during delivery and cause infection. GBS can also infect babies in the womb, or within the first few months after birth.
According to the U.S. Centers for Disease Control and Prevention (CDC), GBS is the leading cause of pneumonia, sepsis, and meningitis in newborns. The majority of cases of GBS disease among newborns occur in the first week of life, with most falling ill within the first 24-48 hours after birth. Before experts investigated preventative measures for early-onset GBS disease in the mid-1980s, an estimated 7,500 cases of neonatal GBS disease occurred annually in the United States. In 2002, GBS disease rates significantly declined when recommendations for universal screening for GBS, along with the use of intrapartum antibiotics, were adopted. Even with these preventative measures, GBS continues to be the leading cause of newborn illness and death, responsible for approximately 1,200 cases of early-onset GBS disease each year.
About one in four pregnant women carry the GBS bacteria. GBS bacteria are among the many bacteria that normally live in the digestive tract. In women, GBS can also live in the genital tract and rectum. Most colonized women are not aware that they carry the bacteria. Carrying GBS does not mean that you are not clean, nor does it mean that you have a sexually transmitted disease. Being a carrier of GBS bacteria does not mean that you have an infection. It only means that you have the GBS bacteria in your body. These bacteria are usually not harmful to you — only to your baby during childbirth or soon after being born. Other people in your house, including children, are not at risk of getting sick from GBS. The bacteria are not spread from food, sex, water, or anything that you might have come in contact with. These bacteria come and go naturally in the body.
Risks for Babies Before and During Delivery
Maternal colonization with GBS during delivery is the primary risk factor for early-onset disease in infants. Babies can be exposed to GBS while passing through the birth canal or when the mother’s water breaks. If a woman is a carrier of the bacteria, there is a 1 in 200 chance that she will pass it on to her infant if antibiotics are not given during delivery. With antibiotics during delivery, the chance of infection drops to around 1 in 4,000. Other risk factors for developing GBS disease include premature delivery, developing a fever during delivery, and having a prolonged period between water breaking and delivery. Premature infants are more vulnerable to the infection than full-term infants and are more likely to suffer from complications or develop late-onset disease. Long-term complications such as deafness and developmental disabilities may also occur. There is evidence that a baby can contract GBS while still in the womb. GBS can also cause miscarriages, still births, and preterm delivery. Even with the improvements in the quality of health care, approximately 4–6 percent of babies with GBS infections die. Not all babies exposed to GBS become infected, but for those who do, the results can be devastating.
Screening and Medications to Help Prevent GBS
The good news is that with GBS screening, prenatal monitoring, and antibiotics, up to 86 percent of GBS infections can be prevented. Regular prenatal exams are essential for baby and mother. The CDC recommends routine vaginal-rectal screening for GBS for all pregnant women in the ninth month (35-37 weeks) of pregnancy. The test involves a painless swab collection of both the vagina and the rectum. The sample is then taken to a lab where it is analyzed for the presence of GBS. Test results are generally available within 24 to 96 hours depending upon the laboratory test method or whether or not susceptibility testing is needed. Since GBS continues to be susceptible to penicillin, ampicillin, and first-generation cephalosporins, susceptibility testing is only necessary when the patient is penicillin-allergic with a high-risk for anaphylaxis.
If you test positive for GBS, discuss a GBS plan with your physician. Physicians will administer antibiotics (usually penicillin) through IV during your delivery to prevent GBS infection. If you are allergic to penicillin, there are alternative antibiotic choices available. Taking antibiotics will greatly decrease the chances of your baby becoming ill. Antibiotics taken before labor will not protect your baby against GBS. The bacteria can grow back so fast that taking medicine before you begin your labor does not prevent bacteria from spreading to your baby during childbirth.
GBS testing is needed for each pregnancy. It doesn’t matter if you have or have not had this type of bacteria before; each pregnancy is different. If you think you might have a C-section or go into labor prematurely, talk with your doctor or nurse about your personal GBS plan.
If you are pregnant, ask your health care professional about testing for GBS. If the test is not offered, you should request it. Ask to be tested for GBS during pregnancy, discuss treatment plans and the use of antibiotics during labor with your doctor if you test positive, and tell your baby’s pediatrician about your result.
As Metropolitan Medical Laboratory celebrates our 100th year in 2014, your good health continues to be our passion. Metropolitan Medical Laboratory, PLC is one of the largest accredited laboratories in the states of Illinois and Iowa, and has provided this community with quality laboratory services for 100 years. Visit www.metromedlab.com. Tell your doctor, “I want to go to Metro.”
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