Targeted Screening to Predict Magnusiomyces Infections in Hematopoietic Cell Transplant Recipients: Evidence from an

Claudia Bartalucci1, Chiara Russo2, Anna Maria Raiola3

  • 1Division of Infectious Diseases, Department of Health Sciences (DISSAL), University of Genoa, 16132 Genoa, Italy.

Insights

A rare fungal infection, Magnusiomyces, caused severe complications in hematopoietic cell transplantation (HCT) patients during an outbreak. Targeted screening showed limited benefit, and most infected patients died despite treatment.

Area of Science:

  • Mycology
  • Infectious Diseases
  • Hematology

Background:

  • Invasive infections by *Magnusiomyces* species are uncommon but linked to severe outcomes in hematopoietic cell transplantation (HCT) recipients.
  • Outbreaks of *Magnusiomyces clavatus* can occur in hospital settings, posing significant risks to immunocompromised patients.

Purpose of the Study:

  • To evaluate a prospective targeted screening protocol for *Magnusiomyces* infections in HCT recipients following an outbreak.
  • To analyze clinical and microbiological data, including whole-genome sequencing (WGS), to understand transmission dynamics.
  • To assess the effectiveness of enhanced screening strategies compared to routine surveillance.

Main Methods:

  • Implementation of a prospective targeted screening protocol using pharyngeal and rectal swabs with prolonged incubation.
  • Clinical and microbiological data collection and analysis.
  • Whole-genome sequencing (WGS) of *Magnusiomyces* isolates to determine clonal relatedness and transmission.
  • Retrospective review of *Magnusiomyces* spp. episodes from 2007-2021.

Main Results:

  • Five colonizations and five invasive *Magnusiomyces* infections were identified during the prospective study period.
  • Despite prompt antifungal treatment, 80% (4/5) of patients with invasive infections died.
  • WGS confirmed clonal transmission of *M. clavatus* among isolates, but no environmental source was identified.
  • Enhanced screening demonstrated limited additional benefit over routine surveillance.

Conclusions:

  • A prolonged clonal outbreak of *Magnusiomyces clavatus* occurred in an HCT unit, highlighting challenges in early detection and prediction of invasive infections.
  • Targeted screening strategies showed limited efficacy in this setting.
  • Further research is required to establish optimal surveillance and prevention strategies for *Magnusiomyces* infections in HCT patients.