Fungal colonization and infections in neonates: long‑term trends and contemporary epidemiological features

   Objective. To characterize the epidemiological and microbiological features of fungal colonization and infections in neonates.

   Materials and methods. An observational epidemiological study was conducted. It comprised a retrospective, single-center analysis of microbiological surveillance data from 2001 to 2025, a prospective, single-center study of fungal colonization and infections from 2021 to 2025, and a multicenter analysis of clinically significant fungal infections in neonates across three hospitals in Saint Petersburg.

   Results. During 2021–2025, 376 cases of fungal infections in neonates were identified in three hospitals. Outbreak-associated cases predominated and accounted for 82.2 % of all infections. Вloodstream infections and catheter-associated bloodstream infections accounted for 85 %. The leading pathogen was Candida parapsilosis, responsible for 40 % of infections. Compared with C. albicans, C. parapsilosis was more frequently associated with invasive infections, bloodstream infections, and catheter-associated bloodstream infections. Positive correlation between the rate of episodes detected on admission and hospital-acquired episodes was revealed, with C. albicans predominating in both groups (r = 0.76). In the prospective, single-center study, colonization accounted for 89.0 % of cases, while 60.3 % were hospital-acquired. Malassezia furfur was detected in 6.1 % of cases and was associated with late hospital-acquired detection.

   Conclusions. Fungal colonization and infections in neonates demonstrate species-specific epidemiological patterns. Hospital spread of C. albicans was mainly associated with strains introduced by colonized patients on admission. In contrast, C. parapsilosis showed hospital transmission and accounted for a substantial proportion of invasive infections and outbreak-associated cases. Detection of M. furfur and other rare yeasts highlights the need for expanded etiological diagnostics in high-risk neonatal units.

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