Culture-Confirmed Bacterial Sepsis and Invasive Fungal Infection in Preterm Infants: NICU Resource Burden, Major Morbidity, and Caregiver Psychological Distress

Background and Objectives: Very preterm infants are vulnerable to late-onset infection and prolonged NICU exposure, with potential downstream effects on caregiver health. We evaluated neonatal outcomes and caregiver psychosocial status across culture-confirmed infection phenotypes. Methods: We investigated a single-center prospective cohort (March 2023–December 2025) of 87 preterm infants assigned to one of three groups: no proven infection (n = 44), bacterial sepsis (n = 31), or candidemia (n = 12). Neonatal outcomes included a composite adverse endpoint (death or major morbidity) and resource utilization. Caregivers completed the SF-36, WHOQOL-BREF, HADS, PHQ-9, GAD-7, and Body Image Scale near discharge. Results: Candidemia occurred later than bacterial sepsis (day of life 17.8 ± 4.8 vs. 10.1 ± 3.9; p < 0.001) and had a longer time to effective therapy (23.3 ± 9.5 vs. 13.3 ± 5.3 h; p = 0.004). The composite adverse outcome was 27.3% in the no-infection group versus 54.8% in the bacterial group and 58.3% in the candidemia group (p = 0.025); ROP requiring treatment increased from 4.5% to 29.0% and 25.0% (p = 0.012). Length of stay rose from 39.7 ± 10.2 to 50.1 ± 11.9 and 60.9 ± 13.1 days (p < 0.001), and ventilation days from 15.7 ± 7.6 to 23.3 ± 7.5 and 34.2 ± 10.4 (p < 0.001). Caregiver SF-36 mental health (MCS) scores decreased from 44.7 ± 7.5 to 38.5 ± 6.0 and 36.7 ± 6.4 (p < 0.001), while PHQ-9 scores increased from 9.4 ± 3.9 to 11.6 ± 3.3 and 15.5 ± 4.6 (p < 0.001); NICU burden correlated with PHQ-9 scores (r = 0.52, p < 0.001). Conclusions: Culture-confirmed infection, particularly candidemia, was associated with higher neonatal morbidity, markedly greater resource use, and substantial caregiver distress at discharge.