Paediatrics: Neonatal infection

2021-03-05 12:00 AM

Neonatal infection can be acquired transplacentally, by an ascent from the vagina, during birth (intrapartum infection), or postnatally from the environment or contact with others.

Neonatal infection

Neonatal infection can be acquired transplacentally, by an ascent from the vagina, during birth (intrapartum infection), or postnatally from the environment or contact with others. Infections are categorized as early-onset (first 48hr of age) vs. late-onset sepsis (>48hr). Preterm infants are at greater risk for both types of infections.

Risk factors for early-onset neonatal sepsis

  • Prolonged rupture of membranes >18hr, especially if preterm.
  • Signs of maternal infection, e.g. maternal fever, chorioamnionitis, UTI.
  • Vaginal carriage or previous infant with GBS.
  • Preterm labour; foetal distress.
  • Skin and mucosal breaks.

Risk factors for late-onset sepsis

  • Central lines and catheters.
  • Congenital malformations, e.g. spina bifida.
  • Severe illness, malnutrition, or immunodeficiency.

Early-onset neonatal infection (2–5/1000 live births)

Infection is caused by organisms acquired from the mother, usually GBS, E. coli, or Listeria. Other possibilities include herpes virus, H. influenza, anaerobes, Candida, and Chlamydia trachomatis.

Presentation (symptomatic)

Includes temperature instability, lethargy, poor feeding, respiratory distress, collapse, DIC, and osteomyelitis or septic arthritis.

Initial investigations

  • These include blood culture, cerebrospinal fluid (glucose, protein, cell count and culture), FBC, CXR.
  • The diagnostic value of CRP in early neonatal sepsis is unclear.
  • Failure to respond within 24hr should prompt further investigation.

Treatment

  • Supportive (may require ventilation, volume expansion, inotropes).
  • Broad-spectrum antibiotics, e.g. penicillin and gentamicin (consider ampicillin/amoxicillin if listeria possibility).
  • If meningitis confirmed or strongly suspected then treatment with cefotaxime (+/– amp/amoxicillin) should be commenced.
  • Length of antibiotic course and choice of antibiotics will depend on local sensitivities/policy as well as the age/gestation of the baby.
  • If the infant has remained well, an initial index of suspicion was low, then consider stopping antibiotics if culture results are negative (748hr), and observe.

The length of treatment in CSF positive meningitis ranges from 14 to 21 days (or greater). A repeat LP demonstrating resolution at the proposed end of treatment may be of value in deciding the length of course.

Prognosis

Up to 15% mortality (up to 30% if VLBW).

Late-onset neonatal infection (4–5/1000 live births)

Infection is caused by environmental organisms such as coagulase –ve staphylococci, Staph. aureusE. coli, and other Gram –ve bacilli, Candida spp., and GBS.

Investigation

FBC, blood culture, urinalysis (clean catch) and urine culture, CSF glucose, protein, cell count and culture.

Treatment

  • Give broad-spectrum antibiotics, e.g. flucloxacillin and gentamicin IV.
  • Consider cefotaxime if meningitis is likely.
  • Vancomycin if coagulase –ve Staph. sepsis likely, e.g. preterm infant with an indwelling central venous catheter. Decisions on removing/ continuing to use any central catheter should be made by a senior doctor.
  • Fungal sepsis is relatively uncommon in the UK (1% of VLBW infants), however, should be considered in any infant who fails to respond to standard therapy or has additional risk factors.