Exam 4 - Group B Streptococcus Infection

Question 1

What is the difference between the two types of GBS - early onset vs late onset?

Answer 1

Early onset - occurs during first 24 hours of life Late onset - occurs during the second week of life

Question 2

How is GBS transmitted to newborns?

Answer 2

Delivery process or intrauterine infection

Question 3

50% of infants with early onset GBS are ___ at birth, which would indicate an ___ infection

Answer 3

50% of infants with early onset GBS are SYMPTOMATIC at birth, which would indicate an INTRAUTERINE infection

Question 4

High risk deliveries are associated with higher rates of GBS infection. What are considered high risk deliveries?

Answer 4

• Premature infants
• SGA infants
• Very low birth weight infants
• Infants born to mothers who have had prolonged rupture of membranes

Question 5

What interventions have helped decrease the rates of GBS infection in newborns?

Answer 5

Widespread chemoprophylaxis

Question 6

Clinical findings/history of newborns associated with GBS

• Before birth

Answer 6

• Infant <37 weeks gestation
• Rupture of membranes 18+ hours
• Maternal fever during labor >100.4 orally
• Previous delivery of a sibling with invasive GBS
• Maternal chorioamnionitis - including rupture of membranes and maternal fever + 2 of the following
  
  • Maternal HR >90 bpm
  • Fetal HR >170 bpm
  • Maternal WBC >15000
  • Uterine tenderness
  • Foul smelling amniotic fluid

Question 7

Clinical findings/history of newborns associated with GBS

• After birth

Answer 7

• Poor feeding
• Temperature instability
• Cyanosis, apnea, tachypnea, grunting, flaring, retracting
• Seizures, lethargy, bulging fontanelle
• Rapid onset and deterioration

Question 8

If GBS infection is suspected in the newborn, what required AND suggested diagnostic tests should be ordered?

Answer 8

Required: CSF and blood culture

Suggested: CBC with diff, CRP, urine culture

Question 9

GBS differential diagnosis

Answer 9

• Respiratory distress syndrome
• Amniotic fluid aspiration syndrome
• Persistent fetal circulation
• Meningitis
• Osteomyelitis
• Septic arthritis
• Sepsis from other infections
• Metabolic problems

Question 10

What category of medication should be started to manage GBS infection?

Answer 10

Antibiotic therapy with a PCN and aminoglycoside until diagnosis is differentiated from e. coli, listeria sepsis, or meningitis

Question 11

What two antibiotic medications could be prescribed to manage GBS?

Answer 11

Ampicillin IV

• Sepsis - ampicillin 50 mg/kg/dose IV q12h for 7-10 days
• Meningitis - ampicillin 100 mg/kg/dose IV q12h for 2 weeks

Gentamicin IV - 2.5 mg/kg/dose IV every 12-24 hours depending on gestational age

Question 12

When should pregnant women be screened for GBS infection?

Answer 12

At 35-37 weeks

Question 13

Is antepartum treatment recommended for asymptomatic GBS-positive moms?

Answer 13

No

Question 14

If GBS cultures come back positive, when do pregnant mothers receive treatment?

Answer 14

Should receive IV PCN or ampicillin at onset of labor

• Repeated q4h until baby is born EXCEPT in the instance of c-section performed before onset of labor on a woman with intact amniotic membranes

Question 15

Are cultures indicated for pregnant women with GBS detected in the urine or have had a previous child with GBS?

Answer 15

Women with GBS detected in the urine or with a previous child with GBS disease do not need cultures

• Should be automatically treated with antibiotics during labor

Question 16

Laboring women with unknown GBS status should be given antibiotics if…

Answer 16

• Labor starts <37 weeks
• Prolonged ROM >18 hours before delivery
• Fever during labor

Question 17

What method of treatment is the ONLY proven method to prevent early onset GBS infection in newborns?

Answer 17

Intrapartum IV antibiotics

Question 18

Do intrapartum IV antibiotics prevent late stage GBS infection?

Answer 18

No - there has been no identified method to prevent late stage disease