The Yeast in the Vial: Iatrogenic Candida viswanathii Infection Associated with Contaminated Milrinone

Background: Iatrogenic fungal infections associated with contaminated parenteral products are uncommon but potentially severe, particularly when the affected patients are critically ill and the microorganism is not included in routine diagnostic panels. Here, we describe C. viswanathii candidemia associated with contaminated milrinone in an extremely preterm infant and place the case within the context of the published clinical evidence. Methods: The infant’s clinical course, microbiological findings, milrinone exposure and pharmaceutical-source investigation were retrospectively reconstructed. Published human C. viswanathii infections were reviewed systematically, together with Italian pharmacovigilance communications concerning milrinone. Results: A 600 g preterm infant developed candidemia on Day 7 of life. A central-venous-catheter (CVC) blood culture became positive for yeasts after 7 h, while the BIOFIRE® Blood Culture Identification 2 (BCID2) Panel remained negative. C. viswanathii was recovered from blood, urine and bronchoalveolar lavage fluid (BAL). Voriconazole was started, and anidulafungin was subsequently added. The infant died on Day 13 following accidental extubation and unsuccessful resuscitation. Exposure reconstruction identified a contaminated milrinone lot, and the source investigation linked the case to the wider Italian multicenter cluster. The literature review showed that C. viswanathii can cause bloodstream, central nervous system, deep-seated and osteoarticular infection, with variable susceptibility, particularly for azoles, but no previous iatrogenic sources were found, and its ecological niche remains undefined. Conclusion: This case provides additional evidence that the Italian C. viswanathii outbreak was an iatrogenic event associated with contaminated milrinone. Recognition depended on combining extended yeast identification with medication-lot traceability and interinstitutional pharmacovigilance.