Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features ++ Early-onset neonatal infection Risk factors Maternal GBS colonization Low or absent maternal GBS anticapsular antibodies Young maternal age Rupture of membranes > 18 hours prior to presentation Gestational age < 37 weeks History of a previous infant with invasive GBS disease African-American or Hispanic ethnicity Newborn younger than 7 days, with rapidly progressing overwhelming sepsis, with or without meningitis Pneumonia with respiratory failure is frequent; chest radiograph resembles that seen in hyaline membrane disease Blood or cerebrospinal fluid (CSF) cultures growing group B streptococci (GBS) Late-onset infection Meningitis, sepsis, or other focal infection in a child aged 1–16 weeks with blood or CSF cultures growing GBS +++ Clinical Findings ++ Early-onset infection Onset of symptoms in the majority of these infants is in the first 48 hours of life, and most are ill within 6 hours Apnea is often the first sign Sepsis, shock, meningitis, apnea, and pneumonia are the most common clinical presentations When infection is complicated by meningitis, more than 80% of the bacterial isolates are serotype III Late-onset infection Occurs in infants between ages 7 days and 4 months (median age at onset is about 4 weeks) Septic arthritis and osteomyelitis, meningitis, occult bacteremia, otitis media, ethmoiditis, conjunctivitis, cellulitis (particularly of the face or submandibular area), lymphadenitis, breast abscess, empyema, and impetigo have been described Exact mode of transmission is not well defined +++ Diagnosis ++ Culture of GBS from a normally sterile site such as blood, pleural fluid, or CSF provides proof of diagnosis Frequent false-positive results limit the usefulness of testing for GBS antigen in urine and CSF +++ Treatment ++ Intravenous ampicillin and an aminoglycoside is the initial regimen of choice for newborns with presumptive invasive GBS disease For neonates 7 days of age or younger with meningitis, the recommended ampicillin dosage is 200–300 mg/kg/d, given intravenously in three divided doses For infants older than 7 days of age, the recommended ampicillin dosage is 300 mg/kg/d, given intravenously in four divided doses In infants with meningitis, the recommended dosage of penicillin G varies with age For infants age 7 days or younger, 250,000–450,000 units/kg/d, given intravenously in three divided doses For infants older than age 7 days, 450,000–500,000 units/kg/d, given intravenously in four divided doses Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.