Late-onset neonatal sepsis The most important risk factor in late-onset sepsis is Preterm delivery Other risk factors include Prolonged use of intravascular catheters Associated illnesses (which may, however, be only a marker for the use of invasive procedures) Exposure to antibiotics (which selects resistant bacterial strains) Prolonged hospitalization Contaminated equipment or IV or enteral solutions Gram-positive organisms (eg, coagulase-negative staphylococci and Staphylococcus aureus) may be introduced from the environment or the patient's skin.