Epidemiology of invasive respiratory disease caused by emerging non-Aspergillus molds in lung transplant recipients

Transpl Infect Dis. 2016 Feb;18(1):70-8. doi: 10.1111/tid.12492. Epub 2016 Feb 3.

Abstract

Objectives: Our aim was to assess the impact of positive cultures for non-Aspergillus molds on the risk of progression to invasive fungal infection (IFI), and the effect of prophylactic nebulized liposomal amphotericin B (n-LAB) on these pathogens.

Methods: This was an observational study (2003-2013) including lung transplant recipients (LTR) receiving lifetime n-LAB prophylaxis, in whom non-Aspergillus molds were isolated on respiratory culture before and after transplantation (minimum 1-year follow-up).

Results: We studied 412 patients, with a mean postoperative follow-up of 2.56 years (interquartile range 1.01-4.65). Pre- and post-transplantation respiratory samples were frequently positive for non-Aspergillus molds (11.9% and 16.9% of LTR respectively). Post transplantation, 10 (2.42%) patients developed non-Aspergillus mold infection (4 Scedosporium species, 4 Purpureocillium species, 1 Penicillium species, and 1 Scopulariopsis species); 5 (1.21%) had IFI, with 60% IFI-related mortality. Non-Aspergillus molds with intrinsic amphotericin B (AB) resistance were more commonly isolated in bronchoscopy samples than AB-variably sensitive or AB-sensitive molds (54.5% vs. 25%, P = 0.04) and were associated with a higher risk of infection (56.3% vs. 1.3%%, P < 0.01).

Conclusions: In LTR undergoing n-LAB prophylaxis, pre- and post-transplantation isolation of non-Aspergillus molds is frequent, but IFI incidence (1.21%) is low. Purpureocillium is an emerging mold. AB-resistant non-Aspergillus species were found more often in bronchoscopy samples and were associated with a higher risk of infection.

Keywords: Purpureocillium; Scedosporium; amphotericin B; emerging fungi; emerging molds; fungal colonization; invasive fungal infections; lung transplant; molds; prophylaxis.

MeSH terms

  • Adult
  • Amphotericin B / therapeutic use*
  • Antifungal Agents / therapeutic use*
  • Ascomycota / isolation & purification
  • Female
  • Fungi / isolation & purification*
  • Humans
  • Invasive Fungal Infections / epidemiology*
  • Invasive Fungal Infections / etiology
  • Invasive Fungal Infections / microbiology
  • Lung Transplantation / adverse effects*
  • Male
  • Middle Aged
  • Penicillium / isolation & purification
  • Respiratory Tract Infections / drug therapy
  • Respiratory Tract Infections / epidemiology*
  • Respiratory Tract Infections / etiology
  • Respiratory Tract Infections / microbiology
  • Scedosporium / isolation & purification
  • Scopulariopsis / isolation & purification
  • Transplant Recipients
  • Young Adult

Substances

  • Antifungal Agents
  • liposomal amphotericin B
  • Amphotericin B