Epidemiology and Clinical Relevance of Pneumocystis jirovecii in Non-Human Immunodeficiency Virus Patients at a Tertiary Care Center in Central Europe: A 3-Year Retrospective Study

<b>Background/Objectives:</b> This study examines the clinical characteristics of <i>Pneumocystis jirovecii</i> pneumonia (PjP) in non-Human immunodeficiency virus (HIV) patients in Hungary to describe its local epidemiological properties. <b>Methods</b>: Our study was conducted at a clinical center with more than 1700 beds at the University of Debrecen in Hungary. We included all patients without HIV infection for whom a diagnostic evaluation for <i>Pneumocystis</i> infection had been requested between 1 January 2022 and 31 December 2024. <b>Results</b>: In total, 21 cases of PjP were identified from 122 requests at the University of Debrecen Clinical Center between 2022 and 2024. The overall 30-day mortality rate was 43% in PjP. Admission to the intensive care unit (odds ratio [OR] 5.44, 95% confidence interval [CI] 1.87-14.09, <i>p</i> = 0.001), the need for mechanical ventilation (OR 4.09, 95% CI 1.45-12.14, <i>p</i> = 0.015) and hematological malignancies (OR 3.24, 95% CI 1.23-9.18, <i>p</i> = 0.024), were associated with <i>Pneumocystis</i> PCR positivity. Furthermore, a significant association was observed between elevated levels of C-reactive protein (OR 1.01, 95% CI 1-1.01, <i>p</i> = 0.001), 30-day mortality (OR 2.86, 95% CI 1.09-7.92, <i>p</i> = 0.049), and <i>Pneumocystis</i> PCR positivity. Regarding diagnostic platforms used, Fujifilm Wako assay detected serum (1-3)-β-D-glucan positivity (>7 pg/mL) from 352 copies/mL in non-HIV patients with probable PJP. <b>Conclusions</b>: Our study serves as a gap-filling investigation, providing an overview of <i>Pneumocystis</i> epidemiology in the Central European region.