Systemic Candida infection in burn patients: a case-control study of management patterns and outcomes

The impact of infection on length of stay in adult burns: A scoping review

BACKGROUND

The disruption to the immune system and profound metabolic response to burn injury gives rise to a unique susceptibility to infection. Indeed, infection is one of the most frequently encountered post-burns complications placing significant burden on patients and healthcare system. Advancements in burn care have led to marked improvements in burn-related mortality and morbidity; however, scarce hospital resources hamper adequate burn-related care, and patient length of stay (LOS) in hospital is an important drain on such resources. The aim of this review was to assess and evaluate the existing literature relating to the impact of infections on LOS in hospitalised, adult burn patients.

METHODS

Electronic searches were performed in Medline and Embase. Eligible studies were those reporting on LOS and infection in adult burn populations. Articles published before 2000 were excluded to ensure that the analysis was focused on contemporary literature that reflects current, clinical management of burn patients.

RESULTS

Nineteen studies (54,397 burn patients) were included in the review. All studies were retrospective, with the majority undertaken in North America (14 studies). The mean age range was 38-67 years and the majority of patients were male. Inhalation injury was recorded in eleven studies. The most common types of infection included pneumonia, blood stream infections (BSI) and burn wound infections. Overall, there was a trend towards a positive association between infection and LOS.

CONCLUSION

The results of this scoping review provide an overview of the existing literature on the relationship between infection and LOS in adult burn populations. However, significant gaps remain in knowledge which call for further high-quality research. Standardised definitions for the collection of infection data and the use of burns specific infection control guidelines are also critical to understanding and improving patient outcomes.

Consensus on the treatment of second-degree burn wounds (2024 edition)

Second-degree burns are the most common type of burn in clinical practice and hard to manage. Their treatment requires not only a consideration of the different outcomes that may arise from the dressing changes or surgical therapies themselves but also an evaluation of factors such as the burn site, patient age and burn area. Meanwhile, special attention should be given to the fact that there is no unified standard or specification for the diagnosis, classification, surgical procedure, and infection diagnosis and grading of second-degree burn wounds. This not only poses great challenges to the formulation of clinical treatment plans but also significantly affects the consistency of clinical studies. Moreover, currently, there are relatively few guidelines or expert consensus for the management of second-degree burn wounds, and no comprehensive and systematic guidelines or specifications for the treatment of second-degree burns have been formed. Therefore, we developed the Consensus on the Treatment of Second-Degree Burn Wounds (2024 edition), based on evidence-based medicine and expert opinion. This consensus provides specific recommendations on prehospital first aid, nonsurgical treatment, surgical treatment and infection treatment for second-degree burns. The current consensus generated a total of 58 recommendations, aiming to form a standardized clinical treatment plan.

Candida albicans Infections: a novel porcine wound model to evaluate treatment efficacy

Candida albicans is a common cause of opportunistic mycoses worldwide and a major contributor in wound infections. The purpose of this study was to establish a fungal wound model and analyze the effects of a common antifungal agent against the proliferation of three C. albicans strains. Second degree burns were created, and then inoculated with one of three different C. albicans ATCC strains: 10261 reference strain, 64550 fluconazole resistant and 26310 fluconazole sensitive. After fungal inoculation, every wound was covered with dressings for 4 h to allow fungal colonization on every wound bed. After 4 h, the dressings were removed, and each wound was treated either once or twice daily with a topical terbinafine hydrochloride or left untreated. On days 2, 4 and 7 post inoculation, three wounds from each treatment group were scrub cultured and quantified. On day 2, wounds infected with the sensitive strains 26310 and 10261 and treated twice showed a significant reduction when compared against those infected wounds receiving once daily treatment. On day 4, wounds which were infected with C. albicans fluconazole sensitive (ATCC 26310) showed a significant reduction in fungal cell counts with treatment applied twice daily. A significant reduction in the colony counts was exhibited in all three strains at the seventh day with active as compared to the non-treated wounds. Twice daily treatment resulted in a lower fungal count than once daily treatment. Neither treatment was able to entirely eradicate C. albicans during the duration of this study. Establishing a reliable fungal wound model will help in the translational goal of identifying new antifungal that could be used clinically by wound care providers.

Species Distribution and Antifungal Susceptibility Pattern of Candida Recovered from Intensive Care Unit Patients, Vietnam National Hospital of Burn (2017-2019)

INTRODUCTION

Candida species is the most common cause of invasive fungal infection. With the wide variation in species distribution and antifungal susceptibility of causative agents, local epidemiological profiles are needed to provide effective guidelines for the treatment of invasive candidiasis.

OBJECTIVE

To find out the species distribution and antifungal susceptibilities of Candida strains isolated from patients in an intensive care unit (ICU) of Vietnam.

METHODS

All patients in ICU of Vietnam National Hospital of Burn with Candida isolation reported from January 2017 to December 2019 were retrospectively studied. Species identification and antifungal susceptibility testing were performed using VITEK 2 Compact. The identification was reconfirmed by sequencing of the internal transcribed spacer regions when needed.

RESULTS

A total of 186 yeasts belonging to ten species were collected. The most common agent was C. tropicalis (45.7%), followed by C. albicans (42.4%), and C. parapsilosis (7.53%). The isolated yeasts showed less susceptibility to fluconazole (resistant rate R 10.7%) than to micafungin, caspofungin, flucytosine and amphotericin B (R 0%, 0.6%, 2.3% and 3.4%, respectively, p < 0.05). C. albicans isolates were more susceptible to fluconazole (R 5.2%) than C. tropicalis (R 15.7%). Resistance to voriconazole was seen only among C. albicans (3.9%) and C. tropicalis isolates (9.9%).

CONCLUSION

Non-albicans species (especially C. tropicalis) is the predominant species, and there is a significant proportion of isolates with reduced susceptibility to azole but not to echinocandin.

Prevalence, species distribution, and risk factors of fungal colonization and infection in patients at a burn intensive care unit in Vietnam

Background and Purpose :

Burn patients are at a higher risk of infections caused by different organisms. This study aimed to address the prevalence, causative species, and factors related to fungal colonization or infection in patients with acute severe injuries admitted to the intensive care unit (ICU) of a burn hospital in northern Vietnam.

Materials and Methods:

This prospective study was conducted on 400 patients in a burn ICU between 2017 and 2019. Clinical samples were weekly collected and screened for fungi, and relevant clinical information was obtained from medical records.

Results:

According to the results, 90% of the patients were colonized with fungi. Out of this group, 12.75% of the cases had invasive fungal infection (IFI). Eleven yeasts and six mold species were isolated from the patients, with the most common species being Candida tropicalis (45.56%) and C. albicans (41.94%). Among the eleven species causing fungal wound infection (FWI), the most common agents were Candida (66.7% of FWI patients) and Aspergillus (38.5%) species. Three Candida species isolated from blood were C. tropicalis (66.7%), C. albicans (20.0%), and C. parapsilosis (14.3%). No factors were found to expose the patients to a higher risk of fungal colonization. However, hyperglycemia, prolonged ICU stay, and heavy Candida species colonization were found to be independently predictive of IFI.

Conclusion:

Burn patients are at the risk of fungal infection with Candida species (especially C. tropicalis) and Aspergillus as the most frequently responsible agents. Continuous surveillance of fungi and appropriate management of pathophysiological consequences are essential to prevent fungal infection in burn patients.

Candidemia in pediatric burn patients: Risk factors and outcomes in a retrospective cohort study

Background and Purpose :

Despite advances in burn care and management, infections are still a major contributor to morbidity and mortality rates in patients with burn injuries. Regarding this, the present study was conducted to investigate the prevalence and importance of candidemia in pediatric burn patients.

Materials and Methods:

Blood samples were collected from the patients and cultured in an automated blood culture system. Candida species were identified using specific culture media. The relationship between candidemia and possible risk factors was evaluated and compared to a control group.

Results:

A total of 71 patients with the mean age of 4.52±3.63 years were included in the study. Blood cultures showed candidemia in 19 (27%) patients. Based on the results, C. albicans was the most common fungus among patients with and without candidemia. The results of statistical analysis also showed that candidemia was significantly correlated with total body surface area (TBSA), mechanical ventilation, duration of total parenteral nutrition, length of intensive care unit (ICU) stay, presence of neutropenia, and R-Baux score (all P≤0.001). In this regard, TBSA, length of ICU stay, R-Baux score, and Candida score were identified as the determinant factors for mortality due to candidemia.

Conclusion:

Candidemia increases the mortality and morbidity rates associated with burn injuries. Prompt diagnostic and prevention measures can reduce the unfortunate outcomes via controlling the possible risk factors.

Outcome and characteristics of invasive fungal infections in critically ill burn patients: A multicenter retrospective study

BACKGROUND

Characteristics and outcome of invasive fungal infection (IFI) in critically ill burn patients have been poorly explored.

OBJECTIVES

We report the factors associated with 90-day mortality in a multicentre retrospective European study.

PATIENTS/METHODS

All burn patients with confirmed IFI admitted between 1 January 2010 to 31 December 2015 in 10 centres in France and Belgium were included.

RESULTS

Ninety-four patients were enrolled with 110 cases of IFIs: 79 (71.8%) were yeasts IFI and 31 (28.2%) filamentous IFI. Incidence was 1% among admitted patients. The 90-day mortality was 37.2% for all IFIs combined, 52% for filamentous infection and 31.9% for yeast infection. Patients with more than one IFI had a higher 90-day mortality than patients with only one episode (61.5% vs 33.5% (P = .006)). In multivariate analysis, higher Simplified Acute Physiology Score II (OR = 1.05 (95% CI: 1.02-1.09) P = .003), bacterial co-infection (OR = 3.85 (95% CI: 1.23-12.01), P = .014) and use of skin allografts at the time of IFI diagnosis (OR = 3.87 (95% CI: 1.31-11.42), P = .021) were associated with 90-day mortality.

CONCLUSIONS

Although rare, invasive fungal infections remain associated with poor outcome in burn patients. Bacterial co-infection and presence of allograft were potentially modifiable factors independently associated with outcome.

Herbal Products for Treatment of Burn Wounds

The purpose of this review is to summarize the current knowledge acquired during preclinical and clinical studies regarding topically used herbal products with burn wound-healing activity. Moreover, antimicrobial, anti-inflammatory, and antioxidant mechanisms of their action as well as adverse effects of herbal therapy will be also described.

Candidemia in major burn patients and its possible risk factors: A 6-year period retrospective study at a burn ICU

OBJECTIVE

The aims of this study were to evaluate the epidemiological and clinical characteristics of candidemia in a typical burn ICU, and to determine the risk factors associated with candidemia among major burn patients.

METHOD

This retrospective observational study of candidemia from 2012 to 2017 in a burn ICU was conducted in the Department of Burn, Southwest hospital, Chongqing, China.

RESULTS

The study included 410 major burn patients (≥40% total body surface area), 39 (9.51%) of which were diagnosed with candidemia. The annual incidences of candidemia varied from 6.06% to 17.54%, and increased gradually in the 6 years. Candida parapsilosis was the dominant pathogen (28.21% strains). The overall resistance rate of Candida spp. to fluconazole was 35.89%. Candidemia cases most frequently occurred in the 2nd (30.77%) and 3rd (23.08%) weeks after burn, and intravascular catheters were the most common sources of bloodstream Candida infections (31.58%). The crude mortality of candidemia was 23.08%, and the mortality attributable to candidemia was 14.99%. Risk factors of candidemia included inhalation injury, renal dysfunction with replacement therapy, severe gastrointestinal complications, T-cell lymphopenia and prior Candida colonization.

CONCLUSION

Candidemia has a high incidence and mortality in major burn patients. The changes in etiology and drug sensitivity may make new challenges for the management of candidemia in burn ICUs.

Outcome and potentially modifiable risk factors for candidemia in critically ill burns patients: A matched cohort study

BACKGROUND

Patients with extensive burns are at risk of developing candidemia.

OBJECTIVES

To identify potentially modifiable risk factors and outcomes of candidemia in critically ill burns patients.

PATIENTS AND METHODS

Retrospective matched cohort study including adult burns patients. Patients who developed candidemia were matched with burns patients with Candida spp colonisation and sepsis or septic shock without candidemia in a ratio of 1:3 (same severity scores and colonisation index). Univariate and multiple regression analyses were performed.

RESULTS

Of 130 severely burned patients with Candida spp colonisation and at least one episode of sepsis or septic shock, 14 were diagnosed with candidemia. In the candidemia group, patients had a median (IQR) total burns surface area (TBSA) of 57 (38-68)%, SAPSII of 43 (36-58) and ABSI of 11 (8-13). Multiple regression analysis showed that only duration of prior antibiotic therapy was independently associated with candidemia. ICU mortality was higher in the candidemia group (71% vs 35% [P = 0.02]). The log-rank test for 28-day mortality comparing patients with candidemia treated with an empirical strategy vs a curative strategy did not reach significance (P = 0.056).

CONCLUSIONS

Burns patients having received recent antibiotherapy have a higher risk of candidemia. Antifungal strategies did not influence outcome in this series.

Animal Models for Pseudomonas aeruginosa Quorum Sensing Studies

Quorum sensing (QS) systems play global regulatory roles in bacterial virulence. They synchronize the expression of multiple virulence factors and they control and modulate bacterial antibiotic tolerance systems and host defense mechanisms. Therefore, it is important to obtain knowledge about QS modes of action and to test putative therapeutics that may interrupt QS actions in the context of infections. This chapter describes methods to study bacterial pathogenesis in murine acute and persistent/relapsing infection models, using the Gram-negative bacterial pathogen Pseudomonas aeruginosa as an example. These infection models can be used to probe bacterial virulence functions and in mechanistic studies, as well as for the assessment of the therapeutic potential of antibacterials, including anti-virulence agents.

Fungal Infection in Thermal Burns: A Prospective Study in a Tertiary Care Centre

INTRODUCTION

Burn Wound Infection (BWI) is primarily caused by aerobic bacteria followed by fungi, anaerobes and viruses. There has been a worldwide decrease in incidence of bacterial infections in burns due to better patient care and availability of effective antibiotics. Consequently, the fungal burn wound infection has shown an increasing trend.

AIM

The aim of study was to assess the frequency of fungal infections in thermal burn wounds with respect to age of wounds, total body surface involved, depth of burns and to assess common fungal pathogens.

MATERIALS AND METHODS

The study was conducted on 50 patients admitted with thermal burn wounds having 20-60% burns in the surgical unit. Pus swab and scrapings were taken under local anaesthesia from each burn patient. Scrapings were put in a sterile container and sent to Mycology section of Microbiology department and were examined by direct microscopy and culture studies on Sabouraud's Dextrose Agar medium in the Mycology section of Microbiology department.

RESULTS

In our study, the incidence of fungal infection in burn wound patients came out to be 26%. The incidence of fungal infection increased with increase in Total Body Surface Area, (TBSA) increase in depth and age of burn. In our study, the maximum positive fungal cultures were seen in the third week of post-burn period. No positive culture was seen in the first week and 30.76% positive fugal cultures were seen in second post-burn week. Candida albicans was found to be the most common organism followed by Non-albicans Candida and Aspergillus.

CONCLUSION

It was concluded from the study that incidence of fungal infections in thermal burns increased with increase in post-burn period and with increasing depth and TBSA of burns. Candida albicans was found to be the most common fungus.

Surveillance of antibiotic susceptibility in a Swedish Burn Center 1994-2012

Patients with burn trauma are at risk for infections caused by antibiotic resistant bacteria (ABR) with subsequent increase in morbidity and mortality. As part of the Swedish strategic program against antibiotic resistance in intensive care (ICU-Strama), we have surveyed the distribution of species and ABR in isolates from patients admitted to a Swedish burn center at Linköping University Hospital from 1994 through 2012. In an international comparison Strama has been successful in reducing the antibiotic consumption among animals and humans in primary care. The aim of this study was to investigate the antibiotic consumption pressure and resistance rates in a Swedish burn unit.

METHODS

Microbiology data, total body surface area (TBSA), patient days, and mortality were collected from a hospital database for all patients admitted to the Burn Center at the University Hospital of Linköping from April 1994 through December 2012.

RESULTS

A total of 1570 patients were admitted with a mean annual admission rate of 83 patients (range: 57-152). 15,006 microbiology cultures (approximately 10 per patient) were collected during the study period and of these 4531 were positive (approximately 3 per patient). The annual mean total body surface area (TBSA) was 13.4% (range 9.5-18.5) with an annual mortality rate of 5.4% (range 1-8%). The MRSA incidence was 1.7% (15/866) which corresponds to an MRSA incidence of 0.34/1000 admission days (TAD). Corresponding figures were for Escherichia coli resistant to 3(rd) generation cephalosporins (ESBL phenotype) 8% (13/170) and 0.3/TAD, Klebsiella spp. ESBL phenotype 5% (6/134) and 0.14/TAD, carbapenem resistant Pseudomonas aeruginosa 26% (56/209) and 1.28/TAD, and carbapenem resistant Acinetobacter spp. 3% (2/64) and 0.04/TAD.

CONCLUSIONS

Our results show a sustained low risk for MRSA and high, although not increasing, risk for carbapenem resistant P. aeruginosa.

Candidemia in major burns patients

Major burn patients have characteristics that make them especially susceptible to candidemia, but few studies focused on this have been published. The objectives were to evaluate the epidemiological, microbiological and clinical aspects of candidemia in major burn patients, determining factors associated with a poorer prognosis and mortality. We conducted a retrospective observational study of candidemia between 1996 and 2012 in major burn patients admitted to the La Fe University Hospital, Valencia, Spain. The study included 36 episodes of candidemia in the same number of patients, 55.6% men, mean age 37.33 years and low associated comorbidity. The incidence of candidemia varied between 0.26 and 6.09 episodes/1000 days stay in the different years studied. Candida albicans was the most common species (61.1%) followed by Candida parapsilosis (27.8%). Candidemia by C. krusei, C. glabrata or C. tropicalis were all identified after 2004. Central vascular catheter (CVC) was established as a potential source of candidemia in 36.1%, followed by skin and soft tissues of thermal injury (22.2%) and urinary tract (8.3%). Fluconazole was used in 19 patients (52.7%) and its in vitro resistance rate was 13.9%. The overall mortality was 47.2%, and mortality related to candidemia was 30.6%. Factors associated with increased mortality were those related to severe infection and shock. CVC was the most usual focus of candidemia. Fluconazole was the most common antifungal drug administered. The management of candidemia in major burn patients is still a challenge.

High Recovery Rate of Non-albicans Candida Species Isolated From Burn Patients With Candidemia in Iran

Background:

Blood stream infections (BSIs) are major causes of morbidity and mortality in burn patients. Microorganisms responsible for BSI are generally bacteria; however, Candida spp. are the infection agents in as many as 8% of all cases. Burn wound colonization and infections are generally the first steps to systemic infection. Candidemia in burn patients has been associated with high mortality and a prolonged hospital stay.

Objectives:

Candidemia in burn patients has been defined as a preterminal event, leading to high morbidity and mortality rates among these patients. The aim of this study was to establish the incidence of candidemia in burn patients in Iran.

Patients and Methods:

We consecutively collected 405 blood samples from 113 burn patients. The yeast isolates were identified to the species level using conventional procedures. In vitro antifungal susceptibility of the Candida isolates to amphotericin B, fluconazole, voriconazole and caspofungin was performed using the Etest.

Results:

Twenty-seven samples (6.7%) of the blood cultures from 13 patients (12%) were positive for Candida species. Candidaparapsilosis (38%) and C. tropicalis (38%) were the most commonly found Candida species, followed by C. albicans (15%) and C. guilliermondii (15%) in the patients. The incidence of candidemia was significantly correlated with increased duration of hospitalization, increased time of stay in the intensive care unit, and higher mortality. The antifungal susceptibility tests demonstrated that amphotericin B and voriconazole had the lowest minimum inhibitory concentrations (MICs) against Candida spp.

Conclusions:

Non-albicans Candida should be considered as significant pathogens in burned patients with candidemia.

Green silver nanoparticles of Phyllanthus amarus: as an antibacterial agent against multi drug resistant clinical isolates of Pseudomonas aeruginosa

BACKGROUND

Pseudomonas aeruginosa infection is a leading cause of morbidity and mortality in burn and immune-compromised patients. In recent studies, researchers have drawn their attention towards ecofriendly synthesis of nanoparticles and their activity against multidrug resistant microbes. In this study, silver nanoparticles were synthesized from aqueous extract of Phyllanthus amarus. The synthesized nanoparticles were explored as a potent source of nanomedicine against MDR burn isolates of P. aeruginosa.

RESULTS

Silver nanoparticles were successfully synthesized using P. amarus extract and the nature of synthesized nanoparticles was analyzed by UV-Vis spectroscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, dynamic light scattering, zeta potential, X- ray diffraction and fourier transform infra-red spectroscopy. The average size of synthesized nanoparticles was 15.7, 24 ± 8 and 29.78 nm by XRD, TEM and DLS respectively. The antibacterial activity of AgNPs was investigated against fifteen MDR strains of P. aeruginosa tested at different concentration. The zone of inhibition was measured in the range of 10 ± 0.53 to 21 ± 0.11mm with silver nanoparticles concentration of 12.5 to 100 μg/ml. The zone of inhibition increased with increase in the concentration of silver nanoparticles. The MIC values of synthesized silver nanoparticles were found in the range of 6.25 to12.5 μg/ml. The MIC values are comparable to the standard antibiotics.

CONCLUSION

The present study suggests that silver nanoparticles from P. amarus extract exhibited excellent antibacterial potential against multidrug resistant strains of P. aeruginosa from burn patients and gives insight of their potential applicability as an alternative antibacterial in the health care system to reduce the burden of multidrug resistance.

Guideline for diagnosis, prophylaxis and treatment of invasive fungal infection post burn injury in China 2013

Invasive fungal infection is one of the major complication of severe burns which can induce local or systemic inflammatory response and cause serious substantial damage to the patient. The incidence of fungal infection for burn victims is increasing dramatically during recent years. This guideline, organized by Chinese Society of Burn Surgeons, aims to standardize the diagnosis, prevention and treatment of burn invasive fungal infection. It can be used as one of the tools for treatment of major burn patients.

Candida identification: a journey from conventional to molecular methods in medical mycology

The incidence of Candida infections have increased substantially in recent years due to aggressive use of immunosuppressants among patients. Use of broad-spectrum antibiotics and intravascular catheters in the intensive care unit have also attributed with high risks of candidiasis among immunocompromised patients. Among Candida species, C. albicans accounts for the majority of superficial and systemic infections, usually associated with high morbidity and mortality often caused due to increase in antimicrobial resistance and restricted number of antifungal drugs. Therefore, early detection of candidemia and correct identification of Candida species are indispensable pre-requisites for appropriate therapeutic intervention. Since blood culture based methods lack sensitivity, and species-specific identification by conventional method is time-consuming and often leads to misdiagnosis within closely related species, hence, molecular methods may provide alternative for accurate and rapid identification of Candida species. Although, several molecular approaches have been developed for accurate identification of Candida species but the internal transcribed spacer 1 and 2 (ITS1 and ITS2) regions of the rRNA gene are being used extensively in a variety of formats. Of note, ITS sequencing and PCR-RFLP analysis of ITS region seems to be promising as a rapid, easy, and cost-effective method for identification of Candida species. Here, we review a number of existing techniques ranging from conventional to molecular approaches currently in use for the identification of Candida species. Further, advantages and limitations of these methods are also discussed with respect to their discriminatory power, reproducibility, and ease of performance.

Changing pattern of fungal infection in burn patients

Invasive fungal burn wound infection is an important emerging cause of late onset morbidity and high mortality in patients with major burns. Following a pilot study done in our unit in 1 year, i.e. January 2008-March 2009 in 71 patients where 28% (20 patients) of the burn wound biopsies from suspected cases showed fungal wound invasion (FWI), a detailed study was planned in order to study the epidemiology of fungal infection in burns in our unit wherein routine wound biopsies in 100 patients were sent on 7th, 14th and 21st postburn day over a one year period (July 2009-June 2010). 12 patients (12%) were diagnosed with FWI on culture. This was then followed by another study in a 9 month period (July 2010-March 2011) when wound samples for only 36 patients in whom there was clinical suspicion of fungal infection were sent. 16 of these patients were diagnosed with fungal wound invasion (FWI) thus establishing an incidence of 44% from suspected cases. These studies showing the increase in fungal infection in our unit have therefore made us wiser, increased our awareness and our accuracy in diagnosing this uncommon infection in extensive burns where patient is not only severely immunocompromised but also has many other risk factors making them more vulnerable to fungal invasion. Another glaring fact which emerged from these studies was the rising incidence of nonalbicans Candida infection compared to Candida albicans, especially C. tropicalis and C. krusei which are more severe in nature and associated with a higher mortality. This signifies that there is a shift of FWI in burns from commensal organism, i.e. C. albicans to pathogenic nosocomial organisms, i.e. C. nonalbicans.

Fungal infections in burns: Diagnosis and management

Burn wound infection (BWI) is a major public health problem and the most devastating form of trauma worldwide. Fungi cause BWI as part of monomicrobial or polymicrobial infection, fungaemia, rare aggressive soft tissue infection and as opportunistic infections. The risk factors for acquiring fungal infection in burns include age of burns, total burn size, body surface area (BSA) (30-60%), full thickness burns, inhalational injury, prolonged hospital stay, late surgical excision, open dressing, artificial dermis, central venous catheters, antibiotics, steroid treatment, long-term artificial ventilation, fungal wound colonisation (FWC), hyperglycaemic episodes and other immunosuppressive disorders. Most of the fungal infections are missed owing to lack of clinical awareness and similar presentation as bacterial infection coupled with paucity of mycology laboratories. Expedient diagnosis and treatment of these mycoses can be life-saving as the mortality is otherwise very high. Emergence of resistance in non-albicans Candida spp., unusual yeasts and moulds in fungal BWI, leaves very few fungi susceptible to antifungal drugs, leaving many patients susceptible. There is a need to speciate fungi as far as the topical and systemic antifungal is concerned. Deep tissue biopsy and other relevant samples are processed by standard mycological procedures using direct microscopy, culture and histopathological examination. Patients with FWC should be treated by aggressive surgical debridement and, in the case of fungal wound infection (FWI), in addition to surgical debridement, an intravenous antifungal drug, most commonly amphotericin B or caspofungin, is prescribed followed by de-escalating with voriconazole or itraconazole, or fluconazole depending upon the species or antifungal susceptibility, if available. The propensity for fungal infection increases, the longer the wound is present. Therefore, the development of products to close the wound more rapidly, improvement in topical antifungal therapy with mould activity and implementation of appropriate systemic antifungal therapy guided by antifungal susceptibility may improve the outcome for severely injured burn victims.

Epidemiological and clinico-mycological profile of fungal wound infection from largest burn centre in Asia

The current study was conducted to know the incidence, predisposing factors, spectrum, clinical profile and antifungal susceptibility (AFS) of fungal wound infection (FWI) in burn patients. Of a total of 71 patients, 20 (28.2%) emerged with the diagnosis of FWI. Fungal pathogens in this study were Candida tropicalis (14%), Candida parapsilosis (5.6%), Aspergillus niger (2.8%) and one each of Candida albicans (1.4%), Candida glabrata (1.4%), Syncephalestrum (1.4%) and Fusarium solani (1.4%). All patients with mould infections expired before the mycological culture results could be conveyed to clinicians. Of the yeasts isolated in the study, one each of C. tropicalis and C. albicans showed cross-resistance to azoles. All the moulds were susceptible to amphotericin B. This study depicted that fungal invasion is associated with a high mortality, burn size 30-60% and high incidence of inhalational injury. Fungal invasion was detected on an average of 14 days after injury. Association of use of four classes of drugs - aminoglycosides, imipenem, vancomycin and third generation cephalosporins and use of total parenteral nutrition was observed. Expedient laboratory diagnosis of FWI and appropriate systemic antifungal therapy guided by AFS may improve outcome for severely injured burn victims.

Candidemia and invasive candidiasis: a review of the literature for the burns surgeon

Advances in critical care, operative techniques, early fluid resuscitation, antimicrobials to control bacterial infections, nutritional support to manage the hypermetabolic response and early wound excision and coverage has improved survival rates in major burns patients. These advances in management have been associated with increased recognition of invasive infections caused by Candida species in critically ill burns patients. Candida albicans is the most common species to cause invasive Candida infections, however, non-albicans Candida species appear to becoming more frequent. These later species may be less fluconazole susceptible than Candida albicans. High crude and attributable mortality rates from invasive Candida sepsis are multi-factorial. Diagnosis of invasive candidiasis and candidemia remains difficult. Prophylactic and pre-emptive therapies appear promising strategies, but there is no specific approach which is well-studied and clearly efficacious in high-risk burns patients. Treatment options for invasive candidiasis include several amphotericin B formulations and newer less toxic antifungal agents, such as azoles and echinocandins. We review the currently available data on diagnostic and management strategies for invasive candidiasis and candidemia; whenever possible providing reference to the high-risk burn patients. We also present an algorithm for the management of candidemia and invasive candidiasis in burn patients.

Fungal colonisation in burn wounds: An Indian scenerio

Burn patients are susceptible hosts for fungal colonisation.

AIM

To study incidence and profile of fungal colonisation of burn wounds.

MATERIALS AND METHODS

This prospective study was conducted in 201 consecutive adult patients (39 male and 162 female) with burn wounds, admitted from October 2005 to September 2006. Wounds with clinical suspicion of fungal colonisation were biopsied and examined by wet smear, Potassium hydroxide (KOH) mount, nigrosin stain, 1% Acid fast bacilli (AFB) stain, Gomori methenamine silver (GMS) stain, histopathological examination and fungal culture. All wounds with suspicion of fungal colonisation were treated with topical application of miconazole ointment mixed with povidone-iodine/silver sulphadiazine topically and itraconazole (oral) systemically.

RESULTS

Fungal infection of burn wound was suspected in 77 patients (38.31%) with 20-70% total body surface area (TBSA) burns. Ninety-two biopsy samples were collected from 77 patients. On investigations, fungal colonisation was confirmed in 35 patients. Culture was positive in 23 patients with Candida in 12 and Aspergillus in 4. GMS stain and KOH stain showed sensitivity and specificity of 70.8% and 86.5%, respectively for detecting fungi in burn wound. Nigrosin stain was negative in all patients. Duration of hospitalisation was more in patients having fungal colonisation without any significant effect on the mortality

DISCUSSION

In 38.31% of patients fungal colonisation was clinically suspected and it was confirmed in 17.41% of 201 patients. GMS stain and KOH stain were observed to have acceptable sensitivity and specificity. With increasing prevalence of Aspergillus, flucanazole cannot be relied upon in controlling fungal colonisation and drugs like itraconazole may have to be used as empirical therapy.

CONCLUSION

Fungal colonisation of burn wound is not uncommon and should be suspected. Fungi detected most commonly were Candida and Aspergillus. KOH and GMS stain were identified as reliable, simple and inexpensive methods for confirming fungal colonisation.

Positive fungal cultures in burn patients: a multicenter review

Fungal infections are increasingly common in burn patients. We performed this study to determine the incidence and outcomes of fungal cultures in acutely burned patients. Members of the American Burn Association's Multicenter Trials Group were asked to review patients admitted during 2002-2003 who developed one or more cultures positive for fungal organisms. Data on demographics, site(s), species and number of cultures, and presence of risk factors for fungal infections were collected. Patients were categorized as untreated (including prophylactic topical antifungals therapy), nonsystemic treatment (nonprophylactic topical antifungal therapy, surgery, removal of foreign bodies), or systemic treatment (enteral or parenteral therapy). Fifteen institutions reviewed 6918 patients, of whom 435 (6.3%) had positive fungal cultures. These patients had mean age of 33.2 +/- 23.6 years, burn size of 34.8 +/- 22.7%TBSA, and 38% had inhalation injuries. Organisms included Candida species (371 patients; 85%), yeast non-Candida (93 patients, 21%), Aspergillus (60 patients, 14%), other mold (39 patients, 9.0%), and others (6 patients, 1.4%). Systemically treated patients were older, had larger burns, more inhalation injuries, more risk factors, a higher incidence of multiple positive cultures, and significantly increased mortality (21.2%), compared with nonsystemic (mortality 5.0%) or untreated patients (mortality 7.8%). In multivariate analysis, increasing age and burn size, number of culture sites, and cultures positive for Aspergillus or other mold correlated with mortality. Positive fungal cultures occur frequently in patients with large burns. The low mortality for untreated patients suggests that appropriate clinical judgment was used in most treatment decisions. Nonetheless, indications for treatment of fungal isolates in burn patients remain unclear, and should be developed.

Topical silver for treating infected wounds

BACKGROUND

Topical silver treatments and silver dressings are increasingly used for the local treatment of contaminated or infected wounds, however, there is a lack of clarity regarding the evidence for their effectiveness.

OBJECTIVES

To evaluate the effects on wound healing of topical silver and silver dressings in the treatment of contaminated and infected acute or chronic wounds.

SEARCH STRATEGY

We sought relevant trials from the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Wounds Group Specialised Register in March 2006 and in MEDLINE, EMBASE, CINAHL, and digital dissertations databases up to September 2006. In addition, we contacted companies, manufacturers and distributors for information to identify relevant trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing the effectiveness of topical silver in the treatment of contaminated and infected acute or chronic wounds.

DATA COLLECTION AND ANALYSIS

Eligibility of trials, assessment of trial quality and data extraction were undertaken by two authors independently. Disagreements were referred to a third author.

MAIN RESULTS

Three RCTs were identified, comprising a total of 847 participants. One trial compared silver-containing foam (Contreet) with hydrocellular foam (Allevyn) in patients with leg ulcers. The second trial compared a silver-containing alginate (Silvercel) with an alginate alone (Algosteril). The third trial compared a silver-containing foam dressing (Contreet)) with best local practice in patients with chronic wounds.The data from these trials show that silver-containing foam dressings did not significantly increase complete ulcer healing as compared with standard foam dressings or best local practice after up to four weeks of follow-up, although a greater reduction of ulcer size was observed with the silver-containing foam. The use of antibiotics was assessed in two trials, but no significant differences were found. Data on pain, patient satisfaction, length of hospital stay, and costs were limited and showed no differences. Leakage occurred significantly less frequently in patients with leg ulcers and chronic wounds treated with a silver dressing than with a standard foam dressing or best local practice in one trial.

AUTHORS' CONCLUSIONS

Only three trials with a short follow-up duration were found. There is insufficient evidence to recommend the use of silver-containing dressings or topical agents for treatment of infected or contaminated chronic wounds.