Organ Dysfunction Varies in Preterm Infant Bacteremia

Organ dysfunction varied widely in severity and course among preterm infants with late-onset bacteremia, even within the same pathogen group, according to a multicenter retrospective cohort study published in JAMA Network Open.

Investigators analyzed 221 preterm infants with late-onset bacteremia. The analysis was limited to first episodes involving a single pathogen in infants born at 33 weeks’ gestation or earlier. The infants received care at 4 academic neonatal intensive care units from January 2012 through February 2025. Researchers calculated hourly neonatal Sequential Organ Failure Assessment (nSOFA) scores from 48 hours before the index blood culture through 14 days after episode onset or death to characterize organ dysfunction trajectories, severity, change, cumulative burden, and timing.

Median gestational age was 27 weeks, and median birth weight was 840 g. At bacteremia evaluation, survivors had a median nSOFA score of 1 (IQR, 0-3). At the index culture, nonsurvivors had a median score of 6 (IQR, 2-9), compared with 1 (IQR, 0-3) among survivors; median maximum scores were 14 (IQR, 12-14) and 4 (IQR, 0-9), respectively. Episode mortality was 9%, including 18% for gram-negative episodes and 5% for gram-positive episodes.

Among survivors, median maximum nSOFA scores were 6 (IQR, 1-9) for gram-negative episodes and 3 (IQR, 0-9) for gram-positive episodes. Median cumulative scores at 168 hours were 311 (IQR, 0-666) and 238 (IQR, 0-531), respectively. The coefficient of variation for cumulative burden remained at least 70% at every 6-hour interval for each pathogen and reached 316%.

The authors noted the retrospective design, reliance on routinely collected clinical variables, lack of detailed infection-source and pathogen-virulence data, the nSOFA score’s inability to capture every potential infection manifestation, and small samples for several pathogen groups. They concluded that adding dynamic organ dysfunction measures to neonatal sepsis research may offer a more informative framework than microbiologic classification alone.

Source: Liu S, Missigman E, Al Gharaibeh FN, et al. Heterogeneity of critical organ dysfunction during late-onset bacteremia in preterm infants. JAMA Netw Open. 2026;9(9):e2632792. doi:10.1001/jamanetworkopen.2026.32792