Abstract
OBJECTIVE: We sought to determine the risk factors, incidence, and mortality of very late onset bacterial infection (blood, urine, or cerebrospinal fluid culture positive occurring after day of life 120) in preterm infants. STUDY DESIGN: A retrospective observational cohort study of all very low birth weight infants cared for between day of life 120 and 365 in 292 neonatal intensive care units in the United States from 1997 to 2008. RESULTS: We identified 3918 infants who were hospitalized beyond 120 days of life. Of these, 1027 (26%) were evaluated with at least 1 culture (blood, urine, or cerebrospinal fluid), and 276 (27%) of the evaluated infants had 414 episodes of culture-positive infection. Gram-positive organisms caused most of the infections (48%). The risk of death was higher in infants with positive cultures (odds ratio; 10.5, 95% confidence interval [7.2-15.5]) or negative cultures (4.8, [3.5-6.7]) compared to infants that were never evaluated with a culture (p<0.001). Mortality was highest with fungal infections (8/24, 33%) followed by Gram-positive cocci (40/142, 28%). CONCLUSIONS: Important predictive risk factors for early and late onset sepsis (birth weight and gestational age) did not contribute to risk of developing very late onset infection. Evaluation for infection (whether positive or negative) was a significant risk factor for death. GPC and fungal infections were associated with high mortality.