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Geaux Tigers!!!! Roll Tide Roll…around the bowl and down the hole!. Welcome applicants! . Morning Report: Friday, November 4 th , 2011. Group B Streptococcal Infections. Background. Encapsulated gram-positive diplococcus Currently 10 known serotypes
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Geaux Tigers!!!! Roll Tide Roll…around the bowl and down the hole! Welcome applicants! Morning Report: Friday, November 4th, 2011
Background • Encapsulated gram-positive diplococcus • Currently 10 known serotypes • Major cause of bacterial infections in pregnant women in the perinatal period • Bacteremia • Amnionitis • Endometritis • UTIs • Also causes focal and systemic infections in newborns
Background • RARE cause of infection in older children and non-pregnant adults • Three types of neonatal infection: • Early-onset disease (EOD): occurs within the first week of life (usually within 72h) • Late-onset disease (LOD): occurs between 1 and 4 weeks of life • Late,late-onset disease: occurs between 1 and 6 months of age • Can be associated with immunodeficiency • Most often seen in premature infants
Epidemiology • Common inhabitant of the maternal GI and genital tract • Colonizes ~20% of pregnant women • Increased risk of colonization • Low SES • Black race • Age <20 yo • Cultures obtained after 35-37 wga have a negative predictive value of 97% and a positive predicitve value of 89%
Epidemiology • Women identified as GBS+ through culture-based screening are 25 times more likely to deliver an infant with EOD. • Identification of colonized women along with intrapartum antibiotic prophylaxis has 80% decrease in EOD (since 2002)
Pathogenesis Early-onset Disease Late-onset Disease • Maternal colonization with GBS in the GI/GU tract and transmission to the infant either in utero or during passage through the birth canal • Horizontal transmission either in the nursery or at home
*Clinical Aspects Spectrum of EOD: bacteremia septic shock; can also see persistent fetal circulation or RDS
Diagnosis • Non-specific testing • Leukocytosis/ left shift • CSF pliocytosis • Elevated acute phase reactants • Lab signs of complications of sepsis (DIC, acidosis, hepatic injury, BM failure) • Isolation of organism from normally sterile site • BCx • CSF Cx • Joint space Cx
Diagnosis • Latex agglutination • Can identify GBS polysaccharide Ag in isolates from culture as well as biologic fluids • Culture more sensitive • Should be used when either mother or infant has been treated with ABx prior to culture
Treatment • Empiric treatment for EOD • Ampicillin (100-150mg/kg/d) AND • Aminoglycoside • Empiric Treatment for LOD • Ampicillin PLUS • Cefotaxime OR Ceftriaxone • Continued for several days until GBS has been isolated (with sensitivities) and there is a good clinical response or the CSF becomes sterile
Treatment • Meningitis • Antibiotic changes: • Penicillin G 300,00U/kg/d • Ampicillin 200-300mg/kg/d • Some experts believe a second LP 24-48h after initiation of therapy aids in management and prognosis
Treatment • Duration • Bacteremia/ PNA/ soft tissue infection • 10 days • Meningitis/ arthritis • 14-21 days • Osteomyelitis/ endocarditis • 21-28 days • *Repeated LPs and diagnostic imaging if response to therapy is unclear
Step 1…Testing! • Universal screening at 35-37wga • Options for GBS identification • Culture of maternal vaginal/ rectal swabs • Positive identification from chromogenic agar media • Nucleic acid amplification tests (NAATs)
Step 2…Who Needs Prophylaxis? • Prophylaxis indicated with: • Previous infant with invasive GBS • GBS bacteruria during the current pregnancy • Positive GBS screen during the current pregnancy • Unknown GBS status AND: • Gestation <37 wks • ROM> 18h • Intrapartum fever >38.0
Step 3…What to Give? • Penicillin is the agent of choice, ampicillin is an acceptable alternative • PCN-allergic women without a history of severe reaction to PCN (anaphylaxis) or cephalosporins should receive cefazolin • PCN-allergic women with high risk of anaphylaxis should receive clindamycin if their isolate is susceptible or Vancomycin if it’s resistant • Adequate IAP= at least 4 hours of penicillin, ampicillin or cefazolin • All others inadequate (including Vanc and Clinda)
Prognosis • Mortality=5% • Major determinates of outcome • Severe prematurity • Septic shock • Periventricularleukomalacia may develop as a sequela of septic shock without meningitis significant DD
Prognosis • After meningitis: • Cortical blindness • Spasticity • Global intellectual disability • Minor or severe • Deafness • Motor defecits
How would you proceed? • Ex 38 wga well-appearing F whose mother had a previous infant with GBS meningitis. Mom received 3 doses of Clindamycin before delivery. ROM 15 hours PTD • Inadequate IAP Observation x48h • Ex 36 wga M born via C-section. ROM at delivery. Mother was GBS+ by screening at 35wga. No IAP was given. The infant has a normal newborn exam. • Routine newborn care IAP not indicated when C/S happens before the onset of labor (membrane are intact)
How would you proceed? • Ex 40 wga healthy M whose mother broke out in a rash when she received PCN as a child. She was GBS+ by screening and received 1 dose of cefazolin 4h PTD. • Adequate IAP Observe for 48 hours, but may be discharged after 24h if all other criteria met and close f/u with PCP possible
How would you proceed? • Ex 37 wga M whose mother was GBS+ treated with 4 doses of ampicillin prior to delivery. Mom had a temp of 101.5 during delivery, and you overheard the OB resident saying they were very suspicious of chorioamnionitis. • Limited evaluation (CBC, BCx) and empiric antibiotics until clinical course and lab evaluation can exclude sepsis (48h)
