|
by David L. Flowers, MD
I overheard a new mom saying that her baby was born with strep. Is that possible? Is it life-threatening?
I’ll answer by citing a recent case:
It is 4 a.m. and a call comes in from the hospital newborn nursery. A baby born via C-section four hours earlier, after an 18 hour failed labor attempt, is suffering from temperature instability, low blood sugars and respiratory distress. The on-call pediatrician orders a stat chest x-ray, laboratory work screening for infection and supplemental oxygen. Feedings are ceased and intravenous fluids with dextrose initiated. Fearing the worst (a possible infection), empiric antibiotic therapy is also started. The drugs of choice are Ampicillin and Gentamicin.
Within 24 hours the newborn’s blood cultures grow the bacteria streptococcus agalactiae, better known among clinicians as Group B Strep (GBS). After three days of treatment and close monitoring in the neonatal intensive care unit, the baby begins to improve, and by the fifth day of life, he is acting like a normal term infant. After five additional days of antibiotics (completing a total of 10) the baby can be safely discharged home.
This case study has a fortunate ending—at discharge the infant is nursing well, is gaining weight, appears neurologically unaffected and has no evidence of hearing deficit. But GBS infection in newborns is notorious among physicians for being the most common cause of lifethreatening neonatal sepsis.
In 15 to 45 percent of healthy women, who may be completely unaware of its presence, GBS colonizes the genital and gastrointestinal tracts. Infants contract the bacteria by vertical transmission of the organisms into the womb, particularly when the birth membranes have been ruptured for a prolonged period. Infection of the baby can also occur during a vaginal delivery. Prematurity (less than 37 weeks gestation) is a significant risk factor for developing GBS sepsis.
Transmission rates of colonized mothers to their infants approach 50 percent, but fortunately, in this country only one to two percent of those infected go on to develop invasive disease, or sepsis as our case newborn did. This equals around two or three per 1,000 live births, and these numbers are declining. GBS can present in infants either as earlyonset sepsis with symptoms of pneumonia or bacteremia (germs in the blood stream) showing up within four to 24 hours of birth, or as late-onset disease, appearing from one week to three months of age, expressed as bacteremia or meningitis.
In 1995 the CDC established guidelines for clinicians administering prenatal and postnatal care to prevent GBS, which includes screening of expecting mothers prior to 37 weeks gestation. These guidelines have since become standards of care, adopted by the American College of Obstetrics and Gynecologists and by the American Academy of Pediatrics, markedly reducing the occurrence of babies becoming septic from GBS.
Our case above is atypical on many counts. C-sections generally lower the risk of GBS transmission, and negative GBS screens are generally very reliable. The twist in our case was that mom’s GBS at 36 weeks of gestation was negative.
What??? GBS negative and she had a C-section? The delivering OB did everything by the book, but despite significant advances in the prevention of GBS sepsis in newborns over the past 14 years, the stark reality is that GBS is nevertheless high on the clinician’s index of suspicion. When a newborn in the nursery “doesn’t act well,” the first three things a clinician considers are infection, infection and infection. Due to the relatively high morbidity and mortality rates of neonatal GBS sepsis, all bets are off until this has been proven or disproven.
To learn more about GBS and other strategies addressing perinatal health, go to the CDC website cdc.gov or the American Academy of Pediatrics website aap.org, and if you’re expecting, make sure you get your GBS screen. It’s the best preventative tool we’ve got.
A native of Columbus, Dr. Flowers graduated from the Medical College of Georgia in Augusta in 1995. Board Certified in general pediatrics, he has been in private practice in Columbus since 1998.
Send us your comments and feedback: contactus@valleyparent.com.
