Epidemiology of fungal infection in burns: Therapeutic implications

Fungal Infection in Burn Patents: A Review of 36 Case Reports

OBJECTIVES

The aims of this study were to review recent fungal infection case reports published, evaluate the treatment regimens and clinical outcomes, and provide recommendations for future management.

METHODS

A review of case reports published over the last decade was conducted. PubMed was searched to collect the relevant citations using a combination of the key words ("burn," "burned," "burns," "fungal," "fungi," and "fungus") in title or abstract. Case series, reviews, guidelines, and experimental and non-English studies were excluded. Statistical analyses were performed using Microsoft Excel 2019.

RESULTS

A total of 36 case reports encompassing a total of 44 burn patients with fungal infection were included in the final analysis. Ablative surgeries, including surgical excision, debridement, skin graft, vitrectomy, teeth extraction, valve replacement, or amputation, were performed in 38 cases after the suspicion or identification of fungal infection. Twenty-nine of them were eventually discharged, yielding a survival rate of 76.3%. In the remaining 6 cases, ablative surgery was not mentioned and 3 of them eventually died, yielding a survival rate of 50%. The total mortality was 27.27%. Among the 12 death cases, 1 was infected with Candida albicans, 1 with non-albicans Candida, 2 with Aspergillus spp, 2 with Fusarium spp, 4 with Zygomycetes, and 2 with other fungal species.

CONCLUSIONS

The overall mortality of fungal wound infection is still high in burn patients around the world, especially those infected with non-Candida species. Early diagnosis of fungal infection, early initiation of appropriate antifungal therapy, and effective surgical intervention are key measures to improve the treatment effect and reduce the mortality of fungal infection in burn patients.

Necrotizing Mucormycosis of Wounds Following Combat Injuries, Natural Disasters, Burns, and Other Trauma

Necrotizing mucormycosis is a devastating complication of wounds incurred in the setting of military (combat) injuries, natural disasters, burns, or other civilian trauma. Apophysomyces species, Saksenaea species and Lichtheimia (formerly Absidia) species, although uncommon as causes of sinopulmonary mucormycosis, are relatively frequent agents of trauma-related mucormycosis. The pathogenesis of these infections likely involves a complex interaction among organism, impaired innate host defenses, and biofilms related to traumatically implanted foreign materials. Effective management depends upon timely diagnosis, thorough surgical debridement, and early initiation of antifungal therapy.

Outbreak of Invasive Wound Mucormycosis in a Burn Unit Due to Multiple Strains of Mucor circinelloides f. circinelloides Resolved by Whole-Genome Sequencing

Mucorales are ubiquitous environmental molds responsible for mucormycosis in diabetic, immunocompromised, and severely burned patients. Small outbreaks of invasive wound mucormycosis (IWM) have already been reported in burn units without extensive microbiological investigations. We faced an outbreak of IWM in our center and investigated the clinical isolates with whole-genome sequencing (WGS) analysis. We analyzed M. circinelloides isolates from patients in our burn unit (BU1, Hôpital Saint-Louis, Paris, France) together with nonoutbreak isolates from Burn Unit 2 (BU2, Paris area) and from France over a 2-year period (2013 to 2015). A total of 21 isolates, including 14 isolates from six BU1 patients, were analyzed by whole-genome sequencing (WGS). Phylogenetic classification based on de novo assembly and assembly free approaches showed that the clinical isolates clustered in four highly divergent clades. Clade 1 contained at least one of the strains from the six epidemiologically linked BU1 patients. The clinical isolates were specific to each patient. Two patients were infected with more than two strains from different clades, suggesting that an environmental reservoir of clonally unrelated isolates was the source of contamination. Only two patients from BU1 shared one strain, which could correspond to direct transmission or contamination with the same environmental source. In conclusion, WGS of several isolates per patients coupled with precise epidemiological data revealed a complex situation combining potential cross-transmission between patients and multiple contaminations with a heterogeneous pool of strains from a cryptic environmental reservoir.

Invasive wound mucormycosis (IWM) is a severe infection due to environmental molds belonging to the order Mucorales. Severely burned patients are particularly at risk for IWM. Here, we used whole-genome sequencing (WGS) analysis to resolve an outbreak of IWM due to Mucor circinelloides that occurred in our hospital (BU1). We sequenced 21 clinical isolates, including 14 from BU1 and 7 unrelated isolates, and compared them to the reference genome (1006PhL). This analysis revealed that the outbreak was mainly due to multiple strains that seemed patient specific, suggesting that the patients were more likely infected from a pool of diverse strains from the environment rather than from direct transmission among them. This study revealed the complexity of a Mucorales outbreak in the settings of IWM in burn patients, which has been highlighted based on WGS combined with careful sampling.