Intravenous ampicillin and an aminoglycoside are recommended for early-onset sepsis For full-term infants less than days of age, 200 to 300 mg/kg/day of ampicillin, intravenously, in three divided doses is the recommended dose; for newborns beyond days of age, 300 mg/kg/day, intravenously, in four divided doses is recommended Cefotaxime can be added for better CNS penetration if gram-negative meningitis is suspected or if renal dysfunction precludes the use of an aminoglycoside Ceftriaxone should be avoided in neonates due to possibility of exacerbating hyperbilirubinemia as a result of bilirubin displacement from albumin, and the possibility of precipitating sludging in the gall bladder Intravenous vancomycin should be considered in neonates who have been at home and exposed to community-acquired Staphylococci Intravenous vancomycin and an aminoglycoside are recommended for empiric therapy of lateonset sepsis until isolation of the specific pathogen occurs; at which time antibiotic therapy can be tailored accordingly Acyclovir should be considered if there is suspicion for herpes simplex infection (suspicious vesicular rash, transaminitis, or history of exposure) Doses and intervals of antibiotics and antivirals can vary according to postgestational age, renal function, and liver function For an expanded discussion on fever in children to months of age, please refer to Chapter 31 Fever Pneumonia in the Newborn Neonatal pneumonia, similar to neonatal sepsis, can occur early (within the first 72 hours of life) or late (after week of life) Early-onset pneumonia occurs as a result of vertical transmission during the perinatal period, possibly through aspiration of infected amniotic fluid or chorioamnionitis Although Group B streptococcal infection is the most common pathogen, other organisms similar to those causing early sepsis can be responsible for infection (bacteria, viruses, and fungi) Chlamydia trachomatis is also acquired perinatally The long incubation period in neonates causes infants to present around to weeks of age with an insidious onset of a staccato cough without fever or wheezing Infants who pass through a vaginal canal infected with C trachomatis have a 3% to 16% risk of developing pneumonia Tuberculosis and syphilis can also cross the placenta to infect the fetus Late-onset pneumonia occurs as a result of horizontal transmission from the infant’s surrounding environment; Streptococcus pneumoniae is the most common organism Other etiologic agents that cause late-onset sepsis are also implicated in development of pneumonia Acute respiratory failure and rapidly evolving pneumonia can occur as a result of Bordetella pertussis infection in