(Canadian Paediatric Society, Fetus and Newborn Committee, Ottawa, Ontario)
Early-onset neonatal bacterial sepsis (EOS) has been defined as sepsis occurring within the first seven days of life; most infants become symptomatic within 24 h of birth. EOS usually results from vertical transmission and, consequently, is associated with organisms that colonize the birth canal. Organisms can ascend to the amniotic fluid, colonizing the infant, or the infant may become colonized during passage through the birth canal. Invasive infection may occur if the skin barrier is broached. Aspiration of infected fluid or transplacental passage of organisms may also result in invasive infection. Following implementation of universal maternal screening for group B streptococcus (GBS) and intrapartum antibiotic prophylaxis (IAP), the incidence of early onset GBS (EOGBS) infection has decreased without concomitant decrease in the incidence of other pathogens. The net result has been an overall decrease in the incidence of EOS. In 2013, 0.5% of infants admitted to Canadian neonatal intensive care units had EOS. In the United States, the overall incidence of EOS has been estimated at 0.77 cases per 1000 live births, with a case fatality rate of 10.9%. Incidence and case fatality rates decrease with increasing gestational age (GA).
In 2007, the Canadian Paediatric Society published recommendations for management of infants at increased risk of EOS. Subsequently, guidelines were published by the United States Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP). As the incidence of EOS is declining, new questions are being raised about the utility of predictive tools and the exposure of well-appearing newborns to antibiotics. This statement provides updated recommendations for the care of term (≥37 weeks’ GA) newborns with risk factors for EOS, during the first 24 h of life.
Newly born unwell term infants (≥37 weeks’ GA)
♦ Infants with clinical signs of sepsis (respiratory distress, temperature instability, tachycardia, seizures, hypotonia, lethargy, poor peripheral perfusion, hypotension, acidosis) require prompt investigation, including CBC, blood culture and lumbar puncture, and initiation of empirical intravenous antibiotic therapy. Ampicillin and an aminoglycoside provide coverage for the most common pathogens associated with early onset sepsis (EOS). Infants who have respiratory signs should also have a chest x-ray. (Strong recommendation, moderate quality evidence.) ♦Infants with early respiratory signs only and without risk factors for sepsis may be observed for up to 6 h before initiating investigations for sepsis and antibiotic therapy. (Strong recommendation, low quality evidence.)
Newly born well-appearing infants (≥37 weeks’ GA)
♦White blood cell (WBC) indices (total WBC count, absolute neutrophil count [ANC], ratio of immature to total neutrophils) or a single C-reactive protein should not be used routinely as screening or diagnostic tests for EOS, nor to routinely exclude EOS. (Strong recommendation, moderate quality evidence.)
♦ For GBS-positive mothers with adequate intrapartum antibiotic prophylaxis (IAP), no additional risk factors OR mothers who are GBS-negative or GBS-unknown status, with one other risk factor and adequate IAP: Infants do not require investigation or treatment for sepsis. They may be discharged home after 24 h if they remain well, meet other discharge criteria and if parents understand signs of sepsis and when to seek medical care. (Strong recommendation, high quality evidence for GBS-positive mother, adequate IAP; low quality evidence for GBS-negative or –unknown mothers.)
♦ For GBS-positive mothers with inadequate IAP and no additional risk factors OR mothers who are GBS-negative or GBS-unknown status, with one other risk factor and inadequate IAP: Infants should be examined at birth, observed closely in hospital with vital signs every 3 h to 4 h, and reassessed before discharge home. They may be discharged home after 24 h if they remain well and meet other discharge criteria, providing there is ready access to health care and the parents understand and are able to seek medical care if the infant develops signs of sepsis. Routine investigation or treatment is not required. (Strong recommendation, low quality evidence.)
♦ Multiple risk factors for sepsis and/or chorioamnionitis: Infants should be investigated and treated using an individualized approach that includes consideration of the severity of risk factors and maternal antibiotic therapy. At minimum, infants should have close observation in hospital for at least 24 h with vital signs every 3 h to 4 h and reassessment before discharge. A CBC done after 4 h of age may be helpful; WBC <5 x 109/L and ANC <1.5 x 109/L have the highest positive predictive value. Some infants may warrant investigation and antibiotic therapy. (Weak recommendation, low quality evidence.)
♦ Well late preterm infants 35 to 36 weeks’ GA
If infants are stable enough to remain with their mother in a mother and baby unit, they can be managed similar to infants ≥37 weeks’ GA, but should be observed in hospital for at least 48 h. (Weak recommendation, low quality evidence.)