Sepsis, Neonatal

Descriptive text is not available for this imageBASICS

DESCRIPTION

  • Clinical syndrome characterized by systemic infection occurring within the first 28 days of life
  • Early-onset sepsis (EOS) and late-onset sepsis (LOS) occur within and following the first 72 hours of life, respectively.
  • Some consider infection within the first 7 days of life early onset, especially in term infants who are not hospitalized.

EPIDEMIOLOGY

  • EOS: 1/1,000 live births in the United States. Incidence is inversely associated with gestational age and birthweight. Highest rates are seen in very low-birth-weight (VLBW) neonates (13/1,000) and neonates born before 28 weeks (18/1,000).
  • LOS in the community: 4/1,000 full-term infants presenting to care. Incidence declines with age. Among febrile neonates, approximately 12% are diagnosed with a serious bacterial infection such as bacteremia, meningitis, or, most commonly, urinary tract infection (UTI).
  • LOS in hospitalized neonates: Incidence is inversely associated with birth weight and is as high as 20–30% for VLBW neonates.

ETIOLOGY

  • EOS:
    • Group B Streptococcus (GBS) (~,30%) and E. coli (~30%) are most common, followed by other streptococci (~10%).
    • Incidence of GBS disease has decreased since initiation of intrapartum antibiotic prophylaxis (IAP).
    • E. coli is the most common pathogen in VLBW infants.
    • Overall incidence of Listeria sepsis is low, but it is more common in preterm infants.
    • Viral pathogens, including herpes simplex viruses (HSV) and enteroviruses, may present with EOS.
  • LOS:
    • For hospitalized neonates, the most common pathogens are coagulase negative staphylococci (CoNS) (~50%), E. coli, Staphylococcus aureus (up to 25% methicillin-resistant), and GBS.
    • For neonates presenting from the community, the most common pathogens include E. coli (~60%), GBS (~20%), and S. aureus (~5%).
    • Pseudomonas aeruginosa carries the highest mortality risk in preterm infants (up to 75%).
    • Consider fungal infections; hospitalized preterm infants are at highest risk.
    • Viral pathogens, including enteroviruses, may present with LOS; viral meningitis is more common in the late-onset period.
    • Perinatally acquired HSV infection should be considered in neonates at any period during the 1st month of age.

RISK FACTORS

  • Neonates are at increased risk for infection due to their immature immune system (permitting relative immune tolerance) and their developing, under-keratinized cutaneous barrier.
  • Maternal factors:
    • Intra-amniotic procedures
    • Prolonged (>18 hours) or premature rupture of membranes
    • Intra-amniotic infection (IAI) or “intrauterine inflammation, infection, or both” (III, “triple I”); new terms describing the heterogeneous conditions labeled previously as chorioamnionitis
    • Presence of cervical cerclage
    • Septic/traumatic delivery
    • Peripartum infection, including UTIs
    • GBS colonization
    • Illicit substance use
    • Inadequate or no prenatal care
    • Poor maternal nutrition
    • Ingestion of contaminated foods during pregnancy (Listeria)
  • Infant factors:
    • Male sex
    • Prematurity or low birth weight
    • Low APGAR scores
    • Congenital anomalies
    • Compromised skin integrity
    • Galactosemia (Escherichia coli sepsis)
    • Invasive procedures
    • Presence of central line, indwelling catheters, or endotracheal tube
    • Prolonged hospitalization

GENERAL PREVENTION

  • Recognize and treat maternal peripartum infections and colonization (i.e., GBS).
  • Follow obstetric practices to reduce risk of IAI/III and maintain postnatal clean cord care.
  • Maintain effective thermoregulation.
  • Encourage early breastfeeding.
  • Practice hand hygiene; avoid fomites.
  • Minimize unnecessary central line use, and follow evidence-based line insertion and maintenance practices.

PATHOPHYSIOLOGY

  • EOS: primarily vertical transmission, with antepartum or intrapartum acquisition of bacteria colonizing the maternal genitourinary tract
  • LOS: primarily due to horizontal transmission or nosocomial infection in hospitalized infants

COMMONLY ASSOCIATED CONDITIONS

  • Meningitis: Up to a quarter of neonates with bacteremia have meningitis
  • Pneumonia
  • UTI
  • Omphalitis
  • Osteomyelitis
  • Severe hyperbilirubinemia
  • Persistent pulmonary hypertension of the newborn (PPHN)
  • Patent ductus arteriosus (PDA)
  • Viral infections: The rate of bacteremia in viral-positive neonates is similar to the rate of bacteremia in viral-negative neonates. Similar testing and treatment for neonatal sepsis is warranted for viral-positive neonates, including those with SARS-CoV-2 infection.

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