Invasive candidiasis: turning risk into a practical prevention policy?

Vitamin D-supplemented yogurt drink reduces Candida infections in a paediatric intensive care unit: a randomised, placebo-controlled clinical trial

BACKGROUND

The prevalence of Candida infections in paediatric intensive care units (PICUs) has dramatically increased as a result of resistance to conventional anti-fungal treatments. Because vitamin D has been shown to exhibit fungicidal activity against Candida infection in an in vitro antimicrobial screening, we aimed to investigate the effect of vitamin D on Candida infections in the PICU.

METHODS

Four hundred sixteen eligible children aged between 12 months to 5 years old admitted to the PICU, who were on broad-spectrum antibiotic therapy, participated in the study. Patients were randomly assigned to two study groups, receiving a plain yogurt drink (placebo group) or supplemented with 300 IU day^-1 vitamin D (VD group). Primary outcome was defined as the incidences of Candida colonisation (Candida isolated from rectal swab) 14 days after enrollment. Secondary outcome measures were Candida growth in blood (candidaemia) and urine (candiduria).

RESULTS

The prevalence of candiduria as well as candidaemia was significantly lower in the VD-treated group (26 cases) than in the placebo group (62 cases). The mean (SD) length of PICU stay was obviously lowered in the VD group [11.8 (1.2) days] compared to the placebo group [15.2 (2.3 days)], whereas cases of patient death were similar between the two groups.

CONCLUSIONS

Supplementation of vitamin D effectively reduces infections of Candida in children who were critically ill and on broad-spectrum antibiotic treatment.

Zinc supplementation reduces Candida infections in pediatric intensive care unit: a randomized placebo-controlled clinical trial

Resistance to anti-fungal drugs has become the main cause for increasing incidence rate of Candida infections in pediatric intensive care units (PICU). Zinc supplementation has been shown to exhibit beneficial effects on many pediatric illnesses. This study aimed to investigate the efficacy of zinc supplementation on prevalence of candidemia and candiduria infections in PICU. 724 eligible children between 1 to 5 years old admitted in PICU were randomly assigned into either zinc supplementation group or placebo group. Primary endpoints were the number of Candida infections, length of PICU stay and cases of patient death 14 days after enrollment. Secondary endpoints were the incidence rates of candidemia and candiduria. The incidences of candiduria and candidemia were significantly lower in the zinc group than the placebo group. The length of PICU stay and cases of patient death were obviously lowered in the zinc group compared to the placebo group. In conclusion, zinc supplementation shows beneficial clinical efficacy in reducing Candida infections among PICU patients on broad-spectrum antibiotics with critical illnesses.

New echinocandin susceptibility patterns for nosocomial Candida albicans in Bogotá, Colombia, in ten tertiary care centres: an observational study

Background

Candida albicans remains as the first cause of nosocomial fungal infections in hospitals worldwide and its susceptibility pattern should be better described in our tertiary care hospitals.

Methods

This study aimed at identifying the caspofungin susceptibility pattern regarding nosocomial Candida albicans infection in ten tertiary care hospitals using the methodology proposed by CLSI M27-A3 and CLSI M27-S4, and its association with risk factors and clinical outcome. The approach involved descriptive research concerning the diagnosis of nosocomial infection during a 7-month period in 10 hospitals in Bogotá, Colombia. Associations were established using exact non-parametric statistical tests having a high statistical power (>95%), suitable for small samples. The exact Mann Whitney test or Kruskall-Wallis non-parametric ANOVA tests were used for distributions which were different to normal or ordinal variables when comparing three or more groups. Multivariate analysis involved using binomial, multinomial and ordinal exact logistical regression models (hierarchical) and discrimination power was evaluated using area under the ROC curve.

Results

101 nosocomial infections were found in 82,967 discharges, for a Candida spp. infection rate of 12.2 per 10,000 discharges, 30.7% caused by C. albicans, 22.8% by C. tropicalis, 20.8% by C. parapsilosis, 19.8% by other Candida, 3% by C. krusei and 3% by C. glabrata. Statistically significant associations between mortality rate and the absence of parenteral nutrition were found in multivariate analysis (OR = 39.746: 1.794-880.593 95% CI: p = 0.020). The model’s predictive power was 83.9%, having an 85.9% significant prediction area (69.5%-100 95% CI; p = 0.001).

Conclusions

Significant differences were found regarding susceptibility results when comparing CLSI M27-A3 to CLSI M27-S4 when shifting clinical break-point values. However, one nosocomial strain was consistent in having reduced susceptibility when using both guidelines without having been directly exposed to echinocandins beforehand and no mutations were found in the FKS1 gene for hot spot 1 and/or hot spot 2 regions, thereby highlighting selective pressure regarding widespread antifungal use in tertiary healthcare centres. Nutritional conditions and low family income were seen to have a negative effect on survival rates.

Intensive care unit-related fluconazole use in Spain and Germany: patient characteristics and outcomes of a prospective multicenter longitudinal observational study

BACKGROUND

Candida spp. are a frequent cause of nosocomial bloodstream infections worldwide.

OBJECTIVE

To evaluate the use patterns and outcomes associated with intravenous (IV) fluconazole therapy in intensive care units in Spain and Germany.

PATIENTS AND METHODS

The research reported here was a prospective multicenter longitudinal observational study in adult intensive care unit patients receiving IV fluconazole. Demographic, microbiologic, therapy success, length of hospital stay, adverse event, and all-cause mortality data were collected at 14 sites in Spain and five in Germany, from February 2004 to November 2005.

RESULTS

Patients (n = 303) received prophylaxis (n = 29), empiric therapy (n = 140), preemptive therapy (n = 85), or definitive therapy (n = 49). A total of 298 patients (98.4%) were treated with IV fluconazole as first-line therapy. The treating physicians judged therapy successful in 66% of prophylactic, 55% of empiric, 45% of preemptive, and 43% of definitive group patients. In the subgroup of 152 patients with proven and specified Candida infection only, 32% suffered from Candida specified as potentially resistant to IV fluconazole. The overall mortality rate was 42%.

CONCLUSION

Our study informs treatment decision makers that approximately 32% of the patients with microbiological results available suffered from Candida specified as potentially resistant to IV fluconazole, highlighting the importance of appropriate therapy.

Prevention, diagnosis, therapy and follow-up care of sepsis: 1st revision of S-2k guidelines of the German Sepsis Society (Deutsche Sepsis-Gesellschaft e.V. (DSG)) and the German Interdisciplinary Association of Intensive Care and Emergency Medicine (Deutsche Interdisziplinäre Vereinigung für Intensiv- und Notfallmedizin (DIVI))

Practice guidelines are systematically developed statements and recommendations that assist the physicians and patients in making decisions about appropriate health care measures for specific clinical circumstances taking into account specific national health care structures. The 1^st revision of the S-2k guideline of the German Sepsis Society in collaboration with 17 German medical scientific societies and one self-help group provides state-of-the-art information (results of controlled clinical trials and expert knowledge) on the effective and appropriate medical care (prevention, diagnosis, therapy and follow-up care) of critically ill patients with severe sepsis or septic shock. The guideline had been developed according to the “German Instrument for Methodological Guideline Appraisal” of the Association of the Scientific Medical Societies (AWMF). In view of the inevitable advancements in scientific knowledge and technical expertise, revisions, updates and amendments must be periodically initiated. The guideline recommendations may not be applied under all circumstances. It rests with the clinician to decide whether a certain recommendation should be adopted or not, taking into consideration the unique set of clinical facts presented in connection with each individual patient as well as the available resources.

Epidemiology of invasive mycoses in North America

The incidence of invasive mycoses is increasing, especially among patients who are immunocompromised or hospitalized with serious underlying diseases. Such infections may be broken into two broad categories: opportunistic and endemic. The most important agents of the opportunistic mycoses are Candida spp., Cryptococcus neoformans, Pneumocystis jirovecii, and Aspergillus spp. (although the list of potential pathogens is ever expanding); while the most commonly encountered endemic mycoses are due to Histoplasma capsulatum, Coccidioides immitis/posadasii, and Blastomyces dermatitidis. This review discusses the epidemiologic profiles of these invasive mycoses in North America, as well as risk factors for infection, and the pathogens' antifungal susceptibility.

Epidemiology, incidence and risk factors for invasive candidiasis in high-risk patients

Candida spp. are an increasing cause of bloodstream infections, and are associated with high morbidity and mortality in both neutropenic and non-neutropenic critically ill patients. Risk factors associated with candidaemia are diverse and include exposure to broad spectrum antimicrobial agents, mucosal colonization by Candida spp., indwelling vascular catheters, prior surgery and cancer chemotherapy. During the last 20 years, there has been an increasing incidence worldwide in invasive candidiasis, but differences in geographical epidemiology are emerging, in particular regarding a shift towards non-albicans species. This shift has been correlated with routine fluconazole prophylaxis adopted in some patients, and the intrinsic/acquired azole resistance of Candida spp., which represents a very real problem, in terms of both selecting the appropriate empirical therapeutic approach and making prophylactic choices.

Recent experience with fungaemia: change in species distribution and azole resistance

Owing to a rise in frequency and change in pattern of cases with fungaemia at our tertiary care centre, we conducted a prospective study for 4 months to understand the epidemiology and outcome of this infection. Detailed case histories including management protocol and outcomes were noted. Records of 140 cases with fungaemia (27.1% adult and 72.9% paediatric patients) were analysed. Although C. tropicalis was the most common yeast isolated, significantly higher isolation of C. guilliermondii (30.4%) and C. pelliculosa (17.6%) was noted in paediatric patients; and C. albicans (26.3%) and C. glabrata (10.5%) in adult patients. Rare species isolated included C. ustus (0.7%) and Trichosporon asahii (2.1%). Mortality was high (56.9% and 47.4%, respectively), in both groups of patients. Resistance to azoles (fluconazole, itraconazole, voriconazole) emerged in C. albicans (12.5-18.8%) and C. tropicalis (10.2-13.6%). Antifungal susceptibility testing report modified the therapy from fluconazole to amphotericin B in 8 patients; 5 survived. In conclusion, the study highlighted the rise of non-albicans Candida species in our hospital with differential distribution in paediatric and adult wards and emergence of azole resistance.

Risk factors for albicans and non-albicans candidemia in the intensive care unit

OBJECTIVE

To determine risk factors for bloodstream infections (BSI) with Candida non-albicans (C-NA) species and Candida albicans (CA) among critically ill patients.

DESIGN

Case-control study.

SETTING

Adult medical and surgical intensive care units (ICUs) at two university hospitals.

PATIENTS

Consecutive patients with C-NA and CA BSIs from 1995-2005 formed the two case groups. Controls were patients without candidemia who were randomly selected in a ratio of 5:1 and matched by study hospital, ICU type (medical vs. surgical) and by ICU admission date within a 3-month period.

INTERVENTIONS

Data collected included demographics, comorbidities, exposure to antibiotics and antifungals, and ICU factors such as total parenteral nutrition (TPN), blood product transfusions, invasive procedures, central venous catheters, hemodialysis, and mechanical ventilation. We built multivariable logistic regression models, which identified risk factors for C-NA or CA BSIs compared with controls. Variables were adjusted for time-at-risk.

MEASUREMENTS AND MAIN RESULTS

There were 67 patients with C-NA BSIs, 79 patients with CA BSIs, and 780 controls. In multivariable models, factors associated with an increased risk of C-NA compared with controls included major pre-ICU operations [odds ratio; (95% confidence interval)] [2.12; (1.14-3.97)], gastrointestinal procedures [2.24; (1.49-3.38)], enteric bacteremia [3.43; (1.39-8.48)], number of hemodialysis days [6.20; (2.67-14.4)], TPN duration [2.87; (1.40-5.90)], and mean number of red blood cell transfusions [2.72; (1.33-5.58)]. Factors associated with an increased risk of CA BSIs compared to controls were very similar and included major ICU operations [1.26; (1.14-3.97)], enteric bacteremia [3.45; (1.38-8.63)], number of hemodialysis days [3.84; (1.75-8.40)], TPN duration [11.0; (5.52-21.7)] and mean number of red blood cell transfusions [1.97; (0.98-3.99)].

CONCLUSIONS

We found multiple common risk factors for both non-C. albicans and C. albicans BSIs, however we could not differentiate between these two groups based on clinical characteristics alone.

Management of Candida infections in the adult intensive care unit

The epidemiology of Candida infection in intensive care units (ICUs) and the management strategies for such infections in non-neutropenic intensive care patients are discussed in this review. Candida species are one of the leading causes of nosocomial bloodstream infections and a significant cause of morbidity in patients admitted to the ICU. Prophylactic, pre-emptive and empiric treatment strategies for Candida infections have been explored in ICU patients. Routine prophylaxis should not be administered to the whole population of ICU patients, because the concerns about the selection of azole-resistant Candida strains or the induction of resistance are justified. Treatment of fungal infections is now possible with newer antifungal agents, including newer azoles (e.g., voriconazole, posaconazole) and echinocandins (e.g., micafungin, anidulafungin). However, there is a critical need for improvement in diagnosis of invasive Candida infection in order to provide clinicians the opportunity to intervene earlier in the diseases course.

[Traditional microbiological diagnosis for invasive candidiasis in critical non-neutropenic patients]

Invasive candidiasis is the most prevalent fungal infection in the critical non neutropenic patient (80%) and is associated with high morbidity-mortality. Microbiological diagnosis is difficult and the positivity of traditional tests appears late in the course of infection. We herein discuss the utility of direct examination and cultures from different sites and the value of surveillance cultures for establishing the likelihood of invasive candidiasis.

[Diagnosis and therapy of sepsis]

A recent survey conducted by the publicly funded Competence Network Sepsis (Sep- Net) reveals that severe sepsis and/or septic shock occurs in 75,000 inhabitants (110 out of 100,000) and sepsis in 79,000 inhabitants (116 out of 100,000) in Germany annually. This illness is responsible for approx. 60,000 deaths and ranges as the third most frequent cause of death after acute myocardial infarction. Direct costs for the intensive care of patients with severe sepsis alone amount to approx. 1.77 billion euros, which means that about 30% of the budget in intensive care is used to treat severe sepsis. However, until now German guidelines for the diagnosis and therapy of severe sepsis did not exist. Therefore, the German Sepsis Society initiated the development of guidelines which are based on international recommendations by the International Sepsis Forum (ISF) and the Surviving Sepsis Campaign (SSC) and take into account the structure and organisation of the German health care system. Priority was given to the following guideline topics: a) diagnosis, b) prevention, c) causative therapy, d) supportive therapy, e) adjunctive therapy. The guidelines development process was carefully planned and strictly adhered to according to the requirements of the Working Group of Scientific Medical Societies (AWMF).

Epidemiology of invasive candidiasis: a persistent public health problem

Invasive candidiasis (IC) is a leading cause of mycosis-associated mortality in the United States. We examined data from the National Center for Health Statistics and reviewed recent literature in order to update the epidemiology of IC. IC-associated mortality has remained stable, at approximately 0.4 deaths per 100,000 population, since 1997, while mortality associated with invasive aspergillosis has continued to decline. Candida albicans remains the predominant cause of IC, accounting for over half of all cases, but Candida glabrata has emerged as the second most common cause of IC in the United States, and several less common Candida species may be emerging, some of which can exhibit resistance to triazoles and/or amphotericin B. Crude and attributable rates of mortality due to IC remain unacceptably high and unchanged for the past 2 decades. Nonpharmacologic preventive strategies should be emphasized, including hand hygiene; appropriate use, placement, and care of central venous catheters; and prudent use of antimicrobial therapy. Given that delays in appropriate antifungal therapy are associated with increased mortality, improved use of early empirical, preemptive, and prophylactic therapies should also help reduce IC-associated mortality. Several studies have now identified important variables that can be used to predict risk of IC and to help guide preventive strategies such as antifungal prophylaxis and early empirical therapy. However, improved non-culture-based diagnostics are needed to expand the potential for preemptive (or early directed) therapy. Further research to improve diagnostic, preventive, and therapeutic strategies is necessary to reduce the considerable morbidity and mortality associated with IC.

[Diagnosis and therapy of sepsis. Guidelines of the German Sepsis Society Inc. and the German Interdisciplinary Society for Intensive and Emergency Medicine]

A recent survey conducted by the publicly funded Competence Network Sepsis (SepNet) reveals that severe sepsis and/or septic shock occurs in 75,000 inhabitants (110 out of 100,000) and sepsis in 79,000 inhabitants (116 out of 100,000) in Germany annually. This illness is responsible for approximately 60,000 deaths and ranges as the third most frequent cause of death after acute myocardial infarction. Direct costs for the intensive care of patients with severe sepsis alone amount to approximately 1.77 billion euros, which means that about 30% of the budget in intensive care is used to treat severe sepsis. However, until now German guidelines for the diagnosis and therapy of severe sepsis did not exist. Therefore, the German Sepsis Society initiated the development of guidelines which are based on international recommendations by the International Sepsis Forum (ISF) and the Surviving Sepsis Campaign (SSC) and take into account the structure and organization of the German health care system. Priority was given to the following guideline topics: a) diagnosis, b) prevention, c) causative therapy, d) supportive therapy, e) adjunctive therapy. The guidelines development process was carefully planned and strictly adhered to the requirements of the Working Group of Scientific Medical Societies (AWMF).

Systematic review and meta-analysis of antifungal agents for preventing fungal infections in liver transplant recipients

A systematic review and meta-analysis was performed to evaluate the benefits and harms of antifungal prophylaxis in liver transplant recipients. Ten randomised trials comparing any prophylactic antifungal regimen with no antifungal agent or with another antifungal regimen were identified from Medline, EMBASE, the Cochrane Library, and other sources. Together, the studies included a total of 1,106 patients. In general, results were consistent across trials despite clinical and methodological heterogeneity. Antifungal prophylaxis did not reduce total mortality (RR 0.84, 95% CI: 0.54-1.3). Fluconazole prophylaxis reduced invasive fungal infections by about 75% (RR 0.28, 95% CI: 0.13-0.57). Although fewer data on prophylactic itraconazole and liposomal amphotericin B were available, indirect comparisons and three direct comparative trials suggested similar efficacy. Fluconazole prophylaxis did not significantly increase colonisation or infection with azole-resistant fungi, although data were limited. A subgroup analysis suggested a dose and duration effect. In conclusion, fluconazole prophylaxis significantly reduces invasive fungal infections in liver transplant recipients and should be instituted in patients at increased risk in the early postoperative period.

Factores de riesgo de la candidiasis invasora: estratificación

Risk factors of invasive candidiasis in the setting of non neutropenic critical patients are well known, although currently there is a need to define and validate in prospective multicenter studies risk assessment strategies that would predict accurately the likelihood of invasive candidiasis. The clinical application in order to define which patients should be treated with antifungal prophylaxis and which groups or subgroups of patients should be assessed prospectively during the risk period in order to validate the new diagnostic microbiological indirect techniques for invasive candidiasis and preemptive treatment should be based in these strategies.

Oral amphotericin B for the prevention of Candida bloodstream infection in critically ill children

OBJECTIVES

To determine the efficacy of oral amphotericin B for the prevention of Candida bloodstream infection in the pediatric intensive care unit.

DESIGN

Retrospective, nonrandomized, historic-control study.

SETTING

Multidisciplinary pediatric intensive care unit at a university-affiliated children's medical center.

PATIENTS

Study group included all patients admitted to the pediatric intensive care unit from January 1, 1998, to December 31, 1999, who required mechanical ventilation and who were admitted for >7 days. The control group included all patients admitted for >7 days who needed mechanical ventilation from January 1, 1994, to December 31, 1997.

INTERVENTIONS

Oral amphotericin B suspension, 50 mg every 8 hrs, administered to all study group patients soon after initiation of mechanical ventilation and terminating after weaning.

MEASUREMENTS

The rates of Candida bloodstream infection were compared between the study and control groups.

MAIN RESULTS

Candida species were isolated from blood cultures in 5 of 185 (2.1%) and 21 of 196 (10.7%) patients in the study and control groups, respectively (p= .0038). There was also a statistically significant (p= .017) decrease in Candida bloodstream infection rate in all patients admitted to the pediatric intensive care unit for >7 days during the study period compared with the Candida bloodstream infection rate during the control period.

CONCLUSION

Prophylactic administration of oral amphotericin B may lead to a significant decrease in the rate of Candida bloodstream infection in ventilated pediatric intensive care unit patients.

Invasive candidiasis in the intensive care unit

OBJECTIVE

To review epidemiologic trends, advances in diagnosis and susceptibility testing, therapeutic options and guidelines, and management strategies for invasive candidiasis as relevant to the intensive care unit physician.

DATA SOURCES, STUDY SELECTION, DATA EXTRACTION, DATA SYNTHESIS

Nonstructured review of peer-reviewed original articles, review articles, abstracts, guidelines, and consensus statements appearing in Medline, major scientific journals, and conference proceedings.

CONCLUSIONS

Invasive candidiasis is a problem associated with substantial morbidity and mortality that is highly prevalent in the intensive care unit setting. Recent epidemiologic studies have shown a trend toward increasing numbers of infections and a shift toward infections caused by non-albicans Candida species. Guidelines for the management of these diseases have been published and recommend amphotericin B, fluconazole, or caspofungin as the primary therapeutic option. The choice of agent should depend on local epidemiology and patient factors. The role of newer antifungal agents for this population, such as the new azoles and echinocandins, remains to be determined. Priority areas of research include diagnostics, risk identification, and management strategy assessment such as prophylactic, preemptive, and empirical therapy.

Antifungal agents for preventing fungal infections in non-neutropenic critically ill and surgical patients: systematic review and meta-analysis of randomized clinical trials

OBJECTIVES

This study aims to systematically identify and summarize the effects of antifungal prophylaxis in non-neutropenic critically ill adult patients on all-cause mortality and the incidence of invasive fungal infections.

METHODS

Systematic review and meta-analysis of randomized controlled trials in all languages comparing the prophylactic use of any antifungal agent or regimen with placebo, no antifungal or another antifungal agent or regimen in non-neutropenic critically ill adult patients. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2005), MEDLINE (1966 to 2 September 2005) and EMBASE (1980 to week 36, 2005). We also hand-searched reference lists, abstracts of conference proceedings and scientific meetings (1998-2004) and contacted authors of included studies and pharmaceutical manufacturers. The primary outcomes assessed were all-cause mortality and proven invasive fungal infections. Two reviewers independently applied selection criteria, performed quality assessment and extracted data using an intention-to-treat approach. Data were synthesized using the random effects model and expressed as relative risk with 95% confidence intervals.

RESULTS

Twelve unique trials (eight comparing fluconazole and four ketoconazole with no antifungal or a non-absorbable agent) involving 1606 randomized patients were included. For both outcomes of total mortality and invasive fungal infections, almost all trials of fluconazole and ketoconazole separately showed a non-significant risk reduction with prophylaxis. When combined, fluconazole/ketoconazole reduced total mortality by one-quarter (relative risk 0.76, 95% confidence interval 0.59-0.97) and invasive fungal infections by about one-half (relative risk 0.46, 95% confidence interval 0.31-0.68). No significant increase in the incidence of infection or colonization with the azole-resistant fungal pathogens Candida glabrata or Candida krusei was demonstrated, although the confidence intervals of the summary effect measures were wide. Adverse effects requiring treatment discontinuation were not more common amongst patients receiving prophylaxis. Results across all trials were homogeneous despite considerable heterogeneity in clinical and methodological characteristics.

CONCLUSIONS

Prophylaxis with fluconazole or ketoconazole in critically ill patients reduces invasive fungal infections by one-half and total mortality by one-quarter. Although no significant increase in azole-resistant Candida species associated with prophylaxis was demonstrated, trials were not powered to exclude such an effect. In patients at increased risk of invasive fungal infections, antifungal prophylaxis with fluconazole should be considered.

Antifungal agents for preventing fungal infections in non-neutropenic critically ill patients

BACKGROUND

Invasive fungal infections, important causes of morbidity and mortality in critically ill patients, may be preventable with the prophylactic administration of antifungal agents.

OBJECTIVES

This study aims to systematically identify and summarize the effects of antifungal prophylaxis in non-neutropenic critically ill adult patients on all-cause mortality and the incidence of invasive fungal infections.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), (The Cochrane Library, Issue 3, 2005), MEDLINE (1966 to 2 September 2005), and EMBASE (1980 to week 36, 2005). We also handsearched reference lists, abstracts of conference proceedings and scientific meetings (1998 to 2004), and contacted authors of included studies and pharmaceutical manufacturers.

SELECTION CRITERIA

We included randomized controlled trials in all languages comparing the prophylactic use of any antifungal agent or regimen with placebo, no antifungal, or another antifungal agent or regimen in non-neutropenic critically ill adult patients.

DATA COLLECTION AND ANALYSIS

Two authors independently applied selection criteria, performed quality assessment, and extracted data using an intention-to-treat approach. We resolved differences by discussion. We synthesized data using the random effects model and expressed results as relative risk with 95% confidence intervals.

MAIN RESULTS

We included 12 unique trials (eight comparing fluconazole and four ketoconazole with no antifungal or a nonabsorbable agent) involving 1606 randomized patients. For both outcomes of total mortality and invasive fungal infections, almost all trials of fluconazole and ketoconazole separately showed a non-significant risk reduction with prophylaxis. When combined, fluconazole/ketoconazole reduced total mortality by about 25% (relative risk 0.76, 95% confidence interval 0.59 to 0.97) and invasive fungal infections by about 50% (relative risk 0.46, 95% confidence interval 0.31 to 0.68). We identified no significant increase in the incidence of infection or colonization with the azole-resistant fungal pathogens Candida glabrata or C. krusei, although the confidence intervals of the summary effect measures were wide. Adverse effects were not more common amongst patients receiving prophylaxis. Results across all trials were homogeneous despite considerable heterogeneity in clinical and methodological characteristics.

AUTHORS' CONCLUSIONS

Prophylaxis with fluconazole or ketoconazole in critically ill patients reduces invasive fungal infections by one half and total mortality by one quarter. Although no significant increase in azole-resistant Candida species associated with prophylaxis was demonstrated, trials were not powered to exclude such an effect. In patients at increased risk of invasive fungal infections, antifungal prophylaxis with fluconazole should be considered.

Prophylaxis of Candida infections in adult trauma and surgical intensive care patients: a systematic review and meta-analysis

OBJECTIVE

To determine whether systemic antifungal prophylaxis decreases infectious morbidity and mortality in nonneutropenic, critically ill, trauma and surgical intensive care unit (ICU) adult patients.

DESIGN

Systematic review and meta-analysis of randomized clinical trials. We used a fixed effect model, with risk ratio (RR) and 95% confidence intervals (CI).

PARTICIPANTS

Patients admitted to ICU after surgery or trauma, with multiple risk factors for fungal infections.

INTERVENTIONS

Nine studies (seven double blind) with a total of 1,226 patients compared ketoconazole (three) or fluconazole (six) to placebo (eight) or no treatment (one).

RESULTS

Prophylaxis with azole was associated with reduced rates of candidemia (RR 0.30, 95% CI 0.10-0.82), mortality attributable to Candida infection (RR 0.25, 95% CI 0.08-0.80), and overall mortality (RR 0.60, 95% CI 0.45-0.81). Time to event analysis showed a significantly lower probability of fungal infections in treated patients. There was no evidence of statistical heterogeneity between studies, and publication bias assessment gave a negative results. There was, however, wide variability in the definition and reporting of some relevant clinical outcomes (e.g., confirmed or suspected infections, colonization) and pooling of these outcome measures was not feasible.

CONCLUSIONS

Prophylaxis of candidal infection among critically ill ICU patients has beneficial effect on certain outcome measures, but additional data from well designed clinical trials and long-term epidemiological observations are needed to provide firm recommendations for the selection of subgroups of patients who would most benefit from prophylaxis and to determine the effect of prophylaxis on fungal resistance patterns.

Candida species distribution in bloodstream cultures in Lyon, France, 1998–2001

In order to determine the types of Candida spp. isolated from bloodstream cultures in Lyon, France, a retrospective study of isolates collected at five different bacteriology laboratories from 1998 to 2001 was conducted. During this period Candida spp. were isolated from 190 patients hospitalized in the internal medicine (32%), hematology (23%) and surgery (23%) wards, and in intensive care units (22%). C. albicans was the leading cause of Candida infection (49.5%), followed by C. glabrata (12.6%) and C. parapsilosis (12.1%). Among the onco-hematology patients, the major cause of candidemia was C. krusei (34%), followed by C. albicans (19%), while these two species were identified in 4% and 59% of patients in the other wards, respectively. In the single onco-hematology ward that was specialized in treating acute myeloid leukemia, 14 C. krusei isolates were identified in this study, which contrasts with the single C. krusei isolate recorded between 1992 and 1996. Since C. krusei has inherent resistance to the antifungal agent fluconazole, prophylactic use of fluconazole in these patients was investigated, but no relationship between these two parameters was found.

Genetic relatedness among Candida tropicalis isolates from sporadic cases of fungemia in two university hospitals in Korea

OBJECTIVE

To compare the epidemiology and genetic relatedness of Candida tropicalis isolates causing bloodstream infection (BSI) in two hospitals.

SETTING

Two tertiary-care hospitals in Korea.

METHODS

A retrospective molecular epidemiologic analysis using pulsed-field gel electrophoresis (PFGE) was performed with 49 C. tropicalis isolates from sporadic cases of BSI. The isolates were collected from 27 patients at Chonnam National University Hospital (CUH) during a 6-year period and 22 patients at Asan Medical Center (AMC) during a 2-year period.

RESULTS

Based on the PFGE patterns, the average similarity value (S AB) for the 27 isolates from CUH was 0.84 +/- 0.08, which was significantly higher than that for the 22 isolates from AMC (0.78 +/- 0.06; P < .001). Of the 49 strains from patients at the 2 hospitals, 9 isolates were placed into 3 subtypes with S AB values of 1.0, which indicated that they were identical. All 9 of these strains were isolated from CUH patients, and each type strain was isolated sporadically during a period ranging from 4 months to 3 years. On comparison of the clinical characteristics of the patients of the 2 hospitals, the CUH strains were isolated more frequently from non-neutropenic patients and patients with central venous catheter-related fungemia; cases from CUH had a better outcome than those from AMC (P < .05).

CONCLUSIONS

These data show that the clinical and epidemiologic characteristics of C. tropicalis fungemia may differ markedly among hospitals and that some cases of C. tropicalis fungemia may be caused by endemic strains within a hospital.

Prophylaxis and treatment of invasive candidiasis in the intensive care setting

The term "invasive candidiasis" encompasses a group of infections of increasing relevance in the intensive care setting. Prophylaxis is an attractive strategy when dealing with diseases of high prevalence, morbidity, and mortality. The success of prophylaxis is determined by the selection of a population at high risk and the use of the safest and most effective drug. Although risk factors for this disease are known, risk assessment strategies need to be developed to predict a high likelihood of disease so that targeted prophylaxis can be offered. Recent advances in antifungal therapy, such as development of the azoles and echinocandins, have resulted in excellent prophylactic and therapeutic choices for the management of this problem.

Molecular cloning and biochemical characterization of Candida albicans acyl-CoA:sterol acyltransferase, a potential target of antifungal agents

To determine whether Candida albicans acyl CoA:sterol acyltransferase (ASAT) can be a potential target enzyme for the protoberberine derivative (HWY-289), we have isolated a gene encoding Ca-ASAT and examined inhibitory effects of HWY-289 on the overexpressed Ca-ASAT. HWY-289 specifically inhibits Ca-ASAT in a non-competitive manner in vitro (IC(50) [9.2microM], K(i) [5.15microM]). The cloned CaARE2 gene (1830 nucleotides [nt]) encodes active Ca-ASAT protein that exhibits a calculated molecular mass of 71.3kDa. The amino acid sequence of CaAre2p is 33.4% and 35.1% identical to those of Saccharomyces cerevisiae ScAre1p and ScAre2p homologues, respectively. Recombinant and endogenous Ca-ASAT displayed identical patterns of inhibition upon exposure to HWY-289 and a preference for cholesterol and oleoyl-CoA as substrates. Northern blot analysis showed that CaARE2 was activated by HWY-289, but not by CI-976 (a human acyl-coenzyme A:cholesterol acyltransferase inhibitor), in a dose-dependent manner (up to 5mg/L), suggesting different selectivities of action between HWY-289 and CI-976 on Ca-ASAT activity.

Incidence of bloodstream infections due to Candida species and in vitro susceptibilities of isolates collected from 1998 to 2000 in a population-based active surveillance program

To determine the incidence of Candida bloodstream infections (BSI) and antifungal drug resistance, population-based active laboratory surveillance was conducted from October 1998 through September 2000 in two areas of the United States (Baltimore, Md., and the state of Connecticut; combined population, 4.7 million). A total of 1,143 cases were detected, for an average adjusted annual incidence of 10 per 100,000 population or 1.5 per 10,000 hospital days. In 28% of patients, Candida BSI developed prior to or on the day of admission; only 36% of patients were in an intensive care unit at the time of diagnosis. No fewer than 78% of patients had a central catheter in place at the time of diagnosis, and 50% had undergone surgery within the previous 3 months. Candida albicans comprised 45% of the isolates, followed by C. glabrata (24%), C. parapsilosis (13%), and C. tropicalis (12%). Only 1.2% of C. albicans isolates were resistant to fluconazole (MIC, > or = 64 microg/ml), compared to 7% of C. glabrata isolates and 6% of C. tropicalis isolates. Only 0.9% of C. albicans isolates were resistant to itraconazole (MIC, > or = 1 micro g/ml), compared to 19.5% of C. glabrata isolates and 6% of C. tropicalis isolates. Only 4.3% of C. albicans isolates were resistant to flucytosine (MIC, > or = 32 microg/ml), compared to < 1% of C. parapsilosis and C. tropicalis isolates and no C. glabrata isolates. As determined by E-test, the MICs of amphotericin B were > or = 0.38 microg/ml for 10% of Candida isolates, > or =1 microg/ml for 1.7% of isolates, and > or = 2 microg/ml for 0.4% of isolates. Our findings highlight changes in the epidemiology of Candida BSI in the 1990s and provide a basis upon which to conduct further studies of selected high-risk subpopulations.

Burden of hospitalization of patients with Candida and Aspergillus infections in Australia

OBJECTIVES

This study examined the burden of hospitalization of patients with Aspergillus and Candida infections in Australia from 1995 to 1999.

METHODS

Data were extracted from the National Hospital Morbidity Database. A hospitalization with an aspergillosis diagnosis was defined as any discharge with a diagnosis of aspergillosis. A hospitalization with a candidiasis diagnosis was defined as any discharge with a diagnosis of disseminated, invasive, or non-invasive candidiasis. Outcome measures included number of hospitalizations, length of stay (LOS), cost (AUS$), and mortality.

RESULTS

4583 hospitalizations with an aspergillosis diagnosis and 57,758 hospitalizations with a candidiasis diagnosis were identified. These hospitalizations were associated with a total of 813,398 hospital days, AUS$563 million in cost, and 4967 in-hospital deaths during the study period. The mean LOS for a hospitalization with an aspergillosis diagnosis was 12 days, cost AUS$9,334, and was associated with 8% mortality. For disseminated, invasive, and non-invasive candidiasis, the respective mean LOS were 31, 17, and 12 days; costs were AUS$33,274, AUS$12,954, and AUS$7,694; and mortality was 26%, 9%, and 8%.

CONCLUSIONS

Hospitalizations with diagnoses for fungal infections were associated with lengthy hospital stays, high costs, and high mortality.

Antifungal agents for preventing fungal infections in solid organ transplant recipients

BACKGROUND

Invasive fungal infections (IFIs) are important causes of morbidity and mortality in solid organ transplant recipients.

OBJECTIVES

This study aims to systematically identify and summarise the effects of antifungal prophylaxis in solid organ transplant recipients.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (Issue 3, 2003), MEDLINE (1966-June 2003), and EMBASE (1980-June 2003) were searched. Reference lists, abstracts of conference proceedings and scientific meetings (1998-2003) were handsearched. Authors of included studies and pharmaceutical manufacturers were contacted.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in all languages comparing the prophylactic use of any antifungal agent or regimen with placebo, no antifungal, or another antifungal agent or regimen.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied selection criteria, performed quality assessment, and extracted data using an intention-to-treat approach. Differences were resolved by discussion. Data were synthesised using the random effects model and expressed as relative risk (RR) with 95% confidence intervals (95% CI).

MAIN RESULTS

Fourteen unique trials with 1497 randomised participants were included. Antifungal prophylaxis did not reduce mortality (RR 0.90, 95% CI 0.57 to 1.44). In liver transplant recipients, a significant reduction in IFIs was demonstrated for fluconazole (RR 0.28, 95% CI 0.13 to 0.57). Although less data were available for itraconazole and liposomal amphotericin B, indirect comparisons and one direct comparative trial suggested similar efficacy. Fluconazole prophylaxis did not significantly increase invasive infections or colonisation with fluconazole-resistant fungi. In renal and cardiac transplant recipients, neither ketoconazole nor clotrimazole significantly reduced invasive infections. Overall, the strength and precision of comparisons however were limited by a paucity of data.

REVIEWERS' CONCLUSIONS

For liver transplant recipients, antifungal prophylaxis with fluconazole significantly reduces the incidence of IFIs with no definite mortality benefit. Given a 10% incidence of IFI, 14 liver transplant recipients would require fluconazole prophylaxis to prevent one infection. In transplant centres where the incidence of IFIs is high, or in situations where the individual risk is great, antifungal prophylaxis should be considered.

New approaches to the risk of Candida in the intensive care unit

PURPOSE OF REVIEW

Candidemia is the fourth most common bloodstream infection in the United States with similar trends reported worldwide. This infection is particularly relevant in the intensive care setting, and is independently associated with increased morbidity and mortality. Identification of patients at risk and developing new prophylactic strategies is a priority area of research. This review focuses on recent advances in risk identification and the groundwork for prophylaxis of invasive candidiasis in the intensive care setting.

RECENT FINDINGS

Although risk factors for invasive candidiasis have been clearly identified (such as colonization, length of stay, use of parenteral nutrition, antibiotics, central lines, and abdominal surgery), there are few risk assessment strategies that clearly define or predict a population at high risk of getting this disease. Currently available risk assessment strategies are yet to be validated in multiple centers and settings. Geographically limited or population specific clinical trials (such as surgical patients) have shown early indications that antifungal prophylaxis is useful in reducing the incidence of invasive candidiasis by more than 50% in units with high incidence of infection, or in carefully selected high-risk patients. Interesting advances in non-culture diagnostic methods and surrogate markers of infection may also have an impact in early identification of infection and preemptive treatment.

SUMMARY

Invasive candidiasis is a relevant problem in the intensive care setting. Better risk assessment strategies will permit identification of the subpopulations of patients that would benefit from prophylactic antifungal therapy the most, having the potential to save millions of lives and dollars.

Attributable Mortality of Nosocomial Candidemia, Revisited

We reexamined the attributable mortality of nosocomial candidemia 15 years after a retrospective cohort study performed at our hospital demonstrated an attributable mortality of 38%. For all episodes of nosocomial candidemia between 1 July 1997 and 30 June 2001, we matched control patients with case patients by age, sex, date of hospital admission, underlying disease(s), length of time at risk, and surgical procedure(s). We analyzed 108 matched pairs. There were no statistically significant differences in age, sex, underlying disease(s), time at risk, surgical procedure, or vital signs at admission between cases and controls. The crude mortality among case patients was 61% (66 of 108 patients), compared with 12% (13 of 108) among control patients, for an attributable mortality of 49% (95% CI, 38%-60%). Nosocomial candidemia is still associated with an extremely high crude and attributable mortality--much higher than that expected from underlying disease alone.

Comparison of glucan detection and galactomannan enzyme immunoassay in gastrointestinal and systemic murine candidiasis

Mouse models of systemic and gastrointestinal infection with the yeast Candida albicans were used to investigate the ability of a commercial mannan antigen enzyme immunoassay and a commercial (1-->3) beta-D-glucan limulus assay to detect systemic infection and to differentiate between colonization and infection. Both assays were positive in all i.v. infected mice and negative in all uninfected control mice. In gastrointestinal infection both tests were positive whenever organ cultures were positive. In colonized mice with no detectable dissemination, there were mostly negative results with the glucan assay whereas the mannan assay was positive or intermediate in all colonized mice. Therefore, in the mouse model used, glucan detection appeared to be superior for differentiation between colonization and dissemination.

Recent trends in the epidemiology of invasive mycoses

PURPOSE OF REVIEW

Invasive mycoses are emerging as an important public health problem. This development has occurred in large measure due to the increasing numbers of persons at risk. In addition, advances in therapeutic technologies and in particular the development of novel immunosuppressive therapies have prolonged the period of risk for many individuals.

RECENT FINDINGS

Although rates of candida bloodstream infections have been increasing over the past several decades, recent evidence suggests this trend may be reversing. The emergence of non-albicans Candida species, and in particular C. glabrata, has been documented. Invasive aspergillosis and other mold infections have become a significant and increasing problem in hematopoietic stem cell transplant recipients and certain high-risk groups of solid organ transplant recipients. These infections are associated with high mortality rates. Despite marked reductions in the rates of AIDS-associated fungal infections in the USA and other developed countries, the burden of these mycoses in developing countries is large and increasing.

SUMMARY

While gains have been made in the treatment and prevention of invasive mycoses, changes in the epidemiology of these infections and in healthcare practices have resulted in the emergence of new at-risk populations. A better understanding of specific risk factors will be needed if prevention strategies, such as chemoprophylaxis and environmental control measures, are to become more widely applicable and cost-effective.

Biofilm production by isolates of Candida species recovered from nonneutropenic patients: comparison of bloodstream isolates with isolates from other sources

Biofilm production has been implicated as a potential virulence factor of some Candida species responsible for catheter-related fungemia in patients receiving parenteral nutrition. We therefore compared clinical bloodstream isolates representing seven different Candida species to each other and to those from other anatomical sites for the capacity to form biofilms in glucose-containing medium. Potential associations between the capacity to form biofilms and the clinical characteristics of fungemia were also analyzed. Isolates included the following from nonneutropenic patients: 101 bloodstream isolates (35 C. parapsilosis, 30 C. albicans, 18 C. tropicalis, 8 C. glabrata, and 10 other Candida species isolates) and 259 clinical isolates from other body sites (116 C. albicans, 53 C. glabrata, 43 C. tropicalis, 17 C. parapsilosis, and 30 other Candida species isolates). Organisms were grown in Sabouraud dextrose broth (SDB) containing a final concentration of 8% glucose to induce biofilm formation, as published previously. Biofilm production was determined by both visual and spectrophotometric methods. In this medium, biofilm production by C. albicans isolates was significantly less frequent (8%) than that by non-C. albicans Candida species (61%; P < 0.0001). The overall proportion of non-C. albicans Candida species isolates from the blood that produced biofilms was significantly higher than that of non-C. albicans Candida isolates obtained from other sites (79% versus 52%; P = 0.0001). Bloodstream isolates of C. parapsilosis alone were significantly more likely to be biofilm positive than were C. parapsilosis isolates from other sites (86% versus 47%; P = 0.0032). Non-C. albicans Candida species, including C. parapsilosis, were more likely to be biofilm positive if isolates were derived from patients whose candidemia was central venous catheter (CVC) related (95%; P < 0.0001) and was associated with the use of total parenteral nutrition (TPN) (94%; P < 0.005). These data suggest that the capacity of Candida species isolates to produce biofilms in vitro in glucose-containing SDB may be a reflection of the pathogenic potential of these isolates to cause CVC-related fungemia in patients receiving TPN.