Years ago, in the early 1970s, I worked as a generalist in a hospital laboratory. One of my jobs was to collect heelstick blood draws in the nursery. I’ll never forget the morning when a pediatrician showed me a baby who was only a few hours old and suffering with devastating group B streptococcus disease. The newborn was cyanotic and lethargic and had difficulty breathing. He had pneumonia, sepsis, and meningitis due to an overwhelming group B streptococcus infection acquired during a normal vaginal delivery. I felt the hopelessness of the physician; no level of intervention at that stage could alter the outcome. The baby expired a few hours later.
Case Study
A woman delivered a baby who developed severe group B streptococcus (GBS) disease. The mother was devastated; she remembered having been cultured for GBS, and the results had come back negative. So why was her baby suffering from this infection now? She retained the services of an attorney, who subpoenaed her medical records. They indicated that she had been screened for group B strep while she was in the thirty-fifth and thirty-seventh week of her pregnancy. The results of the test were negative. What had happened?
Her attorney discovered that the collection site noted in her medical records for her GBS screen was “cervix.” Researching some of the countless articles and papers published on the subject, he discovered that a vaginal/rectal collection was the specimen of choice for screening for group B streptococcus during pregnancy. The cervix, perineum, and vagina alone are considered suboptimal sites and should be rejected and the provider notified.
The physician was sued for inappropriate site collection, and the hospital was sued for accepting and processing the specimen.
It never ceases to amaze me how things can go so wrong when supervisors and directors do not pay close attention to what is being tested and reported in their labs-and where inappropriate policies are set without careful deliberation. And it sometimes seems to take a litigation process to wake them up. Ultimately, in cases like that tragic one it’s the newborn who suffers the consequences of bureaucratic inertia.
The good news, though: During the past 15 years, and as a direct result of extraordinary prevention strategies, the incidence of GBS disease in newborns has declined dramatically.
Prevention of perinatal group B streptococcal disease: highlights from revised CDC Guidelines (2010)
- GBS colonization status should be determined by collecting both vaginal and rectal specimens at 35 to 37 weeks gestation. A single combined vaginal-rectal specimen can be collected. Cervical, perianal, perirectal, or perineal specimens are not acceptable, and a speculum should not be used for culture collection.
- Laboratories should report GBS in urine culture specimens when present at concentrations of ≥104 colony-forming units/mL in pure culture or mixed with a second microorganism.
- Specimen requisitions should indicate clearly that specimens are for group B streptococcal testing. If a woman is determined to be penicillin allergic, susceptibility testing for clindamycin and erythromycin should be ordered. Testing for inducible clindamycin resistance should be performed on antenatal GBS isolates that are susceptible to clindamycin and resistant to erythromycin.
- Specimens should undergo 18- to 24-hour incubation at 35° to 37°C in an appropriate enrichment broth medium to enhance the recovery of GBS prior to subculture to solid media.
- Accurate results are more important than rapid turnaround time for antenatal screening.
Colleen Gannon, MT (AMT) HEW, worked for many years as a microbiology supervisor in a large teaching hospital.
After a short-lived and unrewarding stint as a retiree, she found her niche by traveling throughout the U.S.
doing 13-week microbiology assignments, where she continues to find a wealth of subject matter for “Mentoring Minute.”
