Healthcare-associated infections (HAIs) significantly impact morbidity, mortality, and hospital costs. This study evaluated the relationship between birth weight, the density of central line–associated bloodstream infections (CLABSI) and ventilator-associated pneumonia (VAP), and the microbiological profile in neonatal intensive care units (NICUs) in Ceará between 2021 and 2024.

This was a cross-sectional, quantitative, retrospective study using data from 127 monitored services. Monthly HAI notifications and microbiological profiles were analyzed using data obtained via LimeSurvey and ANVISA bulletins, collected in April 2025.

Newborns weighing <1000 g remained the most vulnerable group to HAIs. In the <750 g category, VAP density was 7.39 in 2021, decreased to 6.59 in 2022, increased to 10.82 in 2023, and declined to 7.38 in 2024. For the 750–999 g group, VAP increased from 3.37 (2021) to 10.01 (2023) and decreased to 6.05 in 2024. In newborns ≥2500 g, VAP rates remained elevated: 5.84 in 2021, 6.19 in 2023, and 5.55 in 2024. Regarding CLABSI, the <750 g group showed a rate of 7.46 in 2024 (the same as in 2021), after a peak of 9.17 in 2023. The 750–999 g group reached 9.87 in 2023 and decreased to 5.67 in 2024; the 1000–1499 g group declined from 6.39 to 4.26 in the same period. In the ≥2500 g group, CLABSI decreased from 10.25 (2021) to 4.92 (2024). In percentile analysis for CLABSI, P10 decreased from 2.81 (2021) to 1.26 (2024), P50 from 4.99 to 3.88, and P90 from 24.28 to 6.99. For VAP, P50 varied from 4.53 (2021) to 4.16 (2024), with a peak of 5.05 in 2023; P90 increased from 11.99 (2021) to 23.80 (2024), after a peak of 52.17 in 2023. Central venous catheter use increased from 61.34% (2021) to 65.02% (2024), while mechanical ventilation decreased slightly from 25.45% to 23.80%, indicating relative stability with a mild reduction. In the microbiological profile of NICUs, coagulase-negative Staphylococcus and Klebsiella pneumoniae remained predominant. An increase in non-albicans Candida (from 24 to 29 cases) and Pseudomonas aeruginosa (from 24 to 28 cases) was observed from 2023 to 2024, suggesting a higher risk related to fungal pathogens and multidrug-resistant Gram-negative organisms.

Neonatal ICUs in Ceará showed significant reductions in CLABSI density across nearly all birth weight categories in 2024, particularly after peaks in 2023, indicating advances in catheter-associated infection prevention. However, VAP rates continued to show marked variability, with persistently high upper percentiles, highlighting ongoing challenges in mechanical ventilation management, especially among extreme birth weight groups. These findings reinforce the need for continuous surveillance and weight-specific prevention strategies, with particular attention to emerging opportunistic pathogens.