Candidate GBS-focused Clinical Questions
RECOMMENDED BY PARENTS WHOSE CHILDREN SUFFERED INVASIVE GROUP B STREP DISEASE
Which of these cervico-vaginal microorganisms appear to cross clinically infected fetal membranes and mediate intra-amniotic infection (IAI)? (Best answer)
a. Group B streptococcus
b. E. coli
c. Mycoplasmas/ureaplasmas
d. Each of these and others
e. None of these
CORRECT: D
a. Group B streptococcus
b. E. coli
c. Mycoplasmas/ureaplasmas
d. Each of these and others
e. None of these
CORRECT: D
Which of these clinical scenarios has NOT been associated with perinatal group B strep infection in the perinate?
a. Cesarean section prior to labor or rupture of membranes*
b. Breast milk asymptomatically colonized with GBS.
c. Fetal membrane “stripping” or “sweeping” to induce labor
d. Untreated GBS asymptomatic bacteriuria
e. All have been associated
CORRECT: E *Per Prevention of Perinatal GBS Disease. Revised Guidelines. MMWR Nov 19 2010; 59: RR-10 “…when a cesarean delivery is performed before onset of labor on a woman with intact amniotic membranes, the risk for early-onset GBS disease among full-term infants is extremely low.”
a. Cesarean section prior to labor or rupture of membranes*
b. Breast milk asymptomatically colonized with GBS.
c. Fetal membrane “stripping” or “sweeping” to induce labor
d. Untreated GBS asymptomatic bacteriuria
e. All have been associated
CORRECT: E *Per Prevention of Perinatal GBS Disease. Revised Guidelines. MMWR Nov 19 2010; 59: RR-10 “…when a cesarean delivery is performed before onset of labor on a woman with intact amniotic membranes, the risk for early-onset GBS disease among full-term infants is extremely low.”
Clinical isolates of group B streptococci are increasingly noted to be resistant to which common antibiotics EXCEPT:
a. Erythromycin
b. Clindamycin
c. Metronidazole
d. Penicillin
e. Cephalosporin
CORRECT: D and E
a. Erythromycin
b. Clindamycin
c. Metronidazole
d. Penicillin
e. Cephalosporin
CORRECT: D and E
Effective means of communicating GBS maternal screening (35-37 week) results include each of these EXCEPT:
a. Giving the mother written results with instructions to present to staff on arrival for delivery care
b. Verbally informing the mother of the results
c. Establishing a system-based mean of informing clinician of GBS results using electronic medical records (EMR)
CORRECT: B
a. Giving the mother written results with instructions to present to staff on arrival for delivery care
b. Verbally informing the mother of the results
c. Establishing a system-based mean of informing clinician of GBS results using electronic medical records (EMR)
CORRECT: B
Which newborn findings are associated with early onset GBS (EOS) infection acquired before birth (prenatal-onset GBS invasive disease [POGBS disease])?
a. Clinically unanticipated low Apgar scores requiring resuscitation
b. Maternal intrapartum fever > 38° C
c. Unexplained fetal death (stillbirth)
d. Evidence of acute infection on placental inspection (“placental triage”)
e. Each of these*
CORRECT: E *Prevention of Perinatal GBS Disease. Revised Guidelines. MMWR Nov 19 2010; 59: RR-10
a. Clinically unanticipated low Apgar scores requiring resuscitation
b. Maternal intrapartum fever > 38° C
c. Unexplained fetal death (stillbirth)
d. Evidence of acute infection on placental inspection (“placental triage”)
e. Each of these*
CORRECT: E *Prevention of Perinatal GBS Disease. Revised Guidelines. MMWR Nov 19 2010; 59: RR-10
Which of these statements regarding asymptomatic GBS bacteriuria is NOT true?
a. Low (<104 cfu/ml) concentration of GBS in urine has been associated with vaginal-rectal colonization and increased risk of perinatal invasive GBS disease.
b. GBS asymptomatic bacteriuria (ASB) is reliably associated with “heavy” cervical colonization and positive vaginal GBS colonization at 35-37 weeks gestation testing.
c. Routine prenatal screening for ASB by “dipstick” urinalysis technique is equivalent (sensitivity) to more costly laboratory culture.
d. Identification and treatment of GBS asymptomatic bacteriuria reduces risks of multiple maternal and perinatal poor outcomes.
CORRECT: C
a. Low (<104 cfu/ml) concentration of GBS in urine has been associated with vaginal-rectal colonization and increased risk of perinatal invasive GBS disease.
b. GBS asymptomatic bacteriuria (ASB) is reliably associated with “heavy” cervical colonization and positive vaginal GBS colonization at 35-37 weeks gestation testing.
c. Routine prenatal screening for ASB by “dipstick” urinalysis technique is equivalent (sensitivity) to more costly laboratory culture.
d. Identification and treatment of GBS asymptomatic bacteriuria reduces risks of multiple maternal and perinatal poor outcomes.
CORRECT: C
True or False? Negative predictive values (NPV) for properly collected vaginal-rectal (introitus and anal sphincter) is high (95-98%) for absence of GBS at delivery, but declines if cultures are performed more than 5 weeks prior to delivery. (Yancey MK, et al. Obstet Gynecol 1996; 88 (5): 811-815)
CORRECT: True
CORRECT: True
In the setting of successful universal GBS prenatal screening, >60% of early onset (EOGBS) occurs in mothers who were screened as NEGATIVE for GBS colonization at 35-37 weeks gestation. Which of these proposed clinical strategies are reasonable to be evaluated in controlled trials (RCT) to reduce early onset GBS disease in negatively screened mothers:
a. Systematic, surveillance, recognition, and treatment of clinical chorioamnionitis in labor (fever, tachycardia, uterine tenderness, foul or purulent amniotic fluid).
b. Clinical recognition that invasive practices such as routine “stripping” or “sweeping” of fetal membranes to induce labor and can inoculate the lower uterine segment with cervico-vaginal microflora and may be avoided.
c. Development of rapid point of care “diagnostic products” (NAAT or PCR) which could indicate significant GBS during labor or after rupture of fetal membranes.
d. Availability of an effective anti-GBS pre-conception or prenatal vaccine.
e. All of these.
CORRECT: E
a. Systematic, surveillance, recognition, and treatment of clinical chorioamnionitis in labor (fever, tachycardia, uterine tenderness, foul or purulent amniotic fluid).
b. Clinical recognition that invasive practices such as routine “stripping” or “sweeping” of fetal membranes to induce labor and can inoculate the lower uterine segment with cervico-vaginal microflora and may be avoided.
c. Development of rapid point of care “diagnostic products” (NAAT or PCR) which could indicate significant GBS during labor or after rupture of fetal membranes.
d. Availability of an effective anti-GBS pre-conception or prenatal vaccine.
e. All of these.
CORRECT: E
Authoritative agencies (CDC-P) recommend empiric intrapartum antibiotic prophylaxis to prevent GBS disease in each of these clinical settings EXCEPT:
a. GBS bacteriuria during any trimester of the current pregnancy, regardless of treatment
b. Positive GBS vaginal-rectal screening culture in late gestation during the current pregnancy
c. Unknown or incomplete GBS screening in any of these clinical settings:
1. Delivery at <37 weeks gestation
2. Rupture fetal membranes > 18 hours
3. Intrapartum fever > 100.4°F (≥38.0°C)
4. Intrapartum rapid test, non-culture (NAAT, PCR) test positive for GBSd. Prior baby with GBS invasive disease
e. Cesarean section not in labor and without rupture of membranes
CORRECT: E
a. GBS bacteriuria during any trimester of the current pregnancy, regardless of treatment
b. Positive GBS vaginal-rectal screening culture in late gestation during the current pregnancy
c. Unknown or incomplete GBS screening in any of these clinical settings:
1. Delivery at <37 weeks gestation
2. Rupture fetal membranes > 18 hours
3. Intrapartum fever > 100.4°F (≥38.0°C)
4. Intrapartum rapid test, non-culture (NAAT, PCR) test positive for GBSd. Prior baby with GBS invasive disease
e. Cesarean section not in labor and without rupture of membranes
CORRECT: E