The role of Candida sp isolated from bronchoscopic samples in nonneutropenic patients

Candida species in community-acquired pneumonia in patients with chronic aspiration

Background

When Candida species is found in a sputum culture, clinicians generally dismiss it as a contaminant. We sought to identify cases of community-acquired pneumonia (CAP) in which Candida might play a contributory etiologic role.

Methods

In a convenience sample of patients hospitalized for CAP, we screened for “high-quality sputum” by Gram stain (> 20 WBC/epithelial cell) and performed quantitative sputum cultures. Criteria for a potential etiologic role for Candida included the observation of large numbers of yeast forms on Gram stain, intracellular organisms and > 10⁶ CFU/ml Candida in sputum. We gathered clinical information on cases that met these criteria for possible Candida infection.

Results

Sputum from 6 of 154 consecutive CAP patients had large numbers of extra- and intracellular yeast forms on Gram stain, with > 10⁶ CFU/ml Candida albicans, glabrata, or tropicalis on quantitative culture. In all 6 patients, the clinical diagnoses at admission included chronic aspiration. Greater than 10⁵ CFU/ml of a recognized bacterial pathogen (Streptococcus pneumoniae, Staphylococcus aureus, or Pseudomonas) or > 10⁶ CFU/ml of other ‘normal respiratory flora’ (Lactobacillus species) were present together with Candida spp. in every case. Blood cultures yielded Candida in 2 cases, and 1,3-beta-D glucan was > 500 ng/mL in 3 of 3 cases in which it was assayed. Since all patients were treated with anti-bacterial and anti-fungal drugs, no inference about etiology can be derived from therapeutic response.

Conclusions

Candida spp. together with a recognized bacterial pathogen or normal respiratory flora may contribute to the cause of CAP in patients who chronically aspirate.

Fatal Immunodeficiency in a Patient with Thymoma and Good's Syndrome

Thymoma is a rare tumor characterized by an association with autoimmune diseases. Immunological abnormalities are increasingly being recognized in thymoma patients and are the cause of a peculiar susceptibility to infections. The authors present the clinical history of a thymoma patient affected by fatal immunodeficiency.

Impact of bronchial colonization with Candida spp. on the risk of bacterial ventilator-associated pneumonia in the ICU: the FUNGIBACT prospective cohort study

INTRODUCTION

Respiratory tract Candida spp. colonization is associated with more frequent bacterial ventilator-associated pneumonia (VAP). However, this colonization could be causally related to VAP or simply reflect the immune paralysis associated with multiple organ failure.

OBJECTIVE

To prospectively evaluate the relationship between Candida spp. colonization and bacterial VAP in mechanically ventilated patients with multiple organ failure.

INCLUSION

Patients receiving mechanical ventilation for > 4 days and presenting multiple organ failure were included. Tracheal colonization with Candida spp. was evaluated at inclusion (day 0, D0) and every 4 days until extubation. Quantitative proximal and tracheal cultures were performed at each VAP episode. Monocyte human leukocyte antigen-DR isotype (mHLA-DR) expression and the ratio of polymononuclear leukocytes to lymphocytes were used to evaluate immunoparalysis at D0 and D7. The relationship between fungal colonization and VAP was modelled using cause-specific models for repeated events with adjustment for time-dependent confounders and immune factors.

RESULTS

A total of 213 patients, with a median age of 64, simplified acute physiology score II (SAPS II) score 55 and sequential organ failure assessment (SOFA) score 10, mainly admitted for medical reasons (n = 197, 92%), were enrolled in 2012-2015. The median ICU stay was 24 days and the mortality rate was 32% (69 cases). Median mHLA-DR was 5916 Ab-bound/cell [3863-8934]; median lymphocyte count, 0.9Giga/L [0.6-1.3]; neutrophil-to-lymphocyte ratio, 10.9 [6.5-19.7]. Overall, 146 cases (68.5%) had tracheal colonization with Candida spp. An episode of VAP occurred (either for the first or only time) in 62 (29.1%) cases 5.5 days (median) after D0; a second episode occurred in 12 (5.6%) cases, 15.5 days (median) after D0. After adjustment, bronchial colonization with Candida was not associated with VAP [adjusted cause-specific hazard ratio = 0.98 (0.59-1.65), p = 0.95].

CONCLUSION

In patients with mechanical ventilation for more than 4 days and multiple organ failure, bronchial colonization with Candida spp. was not associated with VAP, even after adjustment for immune function.

Measuring (1,3)-β-D-glucan in tracheal aspirate, bronchoalveolar lavage fluid, and serum for detection of suspected Candida pneumonia in immunocompromised and critically ill patients: a prospective observational study

Background

While Candida pneumonia is life-threatening, biomarker measurements to early detect suspected Candida pneumonia are lacking. This study compared the diagnostic values of measuring levels of (1, 3)-β-D-glucan in endotracheal aspirate, bronchoalveolar lavage fluid, and serum to detect suspected Candida pneumonia in immunocompromised and critically ill patients.

Methods

This prospective, observational study enrolled immunocompromised, critically ill, and ventilated patients with suspected fungal pneumonia in mixed intensive care units from November 2010 to October 2011. Patients with D-glucan confounding factors or other fungal infection were excluded. Endotracheal aspirate, bronchoalveolar lavage fluid and serum were collected from each patient to perform a fungal smear, culture, and D-glucan assay.

Results

After screening 166 patients, 31 patients completed the study and were categorized into non-Candida pneumonia/non-candidemia (n = 18), suspected Candida pneumonia (n = 9), and non-Candida pneumonia/candidemia groups (n = 4). D-glucan levels in endotracheal aspirate or bronchoalveolar lavage were highest in suspected Candida pneumonia, while the serum D-glucan level was highest in non-Candida pneumonia/candidemia. In all patients, the D-glucan value in endotracheal aspirate was positively correlated with that in bronchoalveolar lavage fluid. For the detection of suspected Candida pneumonia, the predictive performance (sensitivity/specificity/D-glucan cutoff [pg/ml]) of D-glucan in endotracheal aspirate and bronchoalveolar lavage fluid was 67%/82%/120 and 89%/86%/130, respectively, accounting for areas under the receiver operating characteristic curve of 0.833 and 0.939 (both P < 0.05), respectively. Measuring serum D-glucan was of no diagnostic value (area under curve =0.510, P = 0.931) for the detection of suspected Candida pneumonia in the absence of concurrent candidemia.

Conclusions

D-glucan levels in both endotracheal aspirate and bronchoalveolar lavage, but not in serum, provide good diagnostic values to detect suspected Candida pneumonia and to serve as potential biomarkers for early detection in this patient population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2364-2) contains supplementary material, which is available to authorized users.

Antifungal use in immunocompetent, critically ill patients with pneumonia does not improve clinical outcomes

PURPOSE

To determine if treating bronchoalveolar lavage (BAL) culture-positive patients with antifungal therapy impacted mortality compared to not treating due to presumed colonization.

METHODS

We conducted a retrospective study of immunocompetent, critically ill adult patients from 2010 to 2014. Patients with a BAL culture-positive for Candida or unspeciated yeast and a clinical suspicion of pneumonia were included. The treatment group received an antifungal agent for at least 5 days, and the control group received either no antifungal therapy or an antifungal agent for less than 48 h. Recruitment occurred in a 2:1 ratio of untreated versus treated patients.

RESULTS

Seventy-five patients were included. In-hospital mortality was similar between treated and untreated groups (24% vs. 26%, P = 0.85). Length of stay and duration of mechanical ventilation also did not differ between the two groups.

CONCLUSION

We did not observe a difference in mortality or clinical outcomes in patients treated with antifungal agents. Presumptive antifungal therapy for BAL-positive Candida or yeast in immunocompetent patients did not result in improved clinical outcomes.

Characterisation of Candida within the Mycobiome/Microbiome of the Lower Respiratory Tract of ICU Patients

Whether the presence of Candida spp. in lower respiratory tract (LRT) secretions is a marker of underlying disease, intensive care unit (ICU) treatment and antibiotic therapy or contributes to poor clinical outcome is unclear. We investigated healthy controls, patients with proposed risk factors for Candida growth in LRT (antibiotic therapy, ICU treatment with and without antibiotic therapy), ICU patients with pneumonia and antibiotic therapy and candidemic patients (for comparison of truly invasive and colonizing Candida spp.). Fungal patterns were determined by conventional culture based microbiology combined with molecular approaches (next generation sequencing, multilocus sequence typing) for description of fungal and concommitant bacterial microbiota in LRT, and host and fungal biomarkes were investigated. Admission to and treatment on ICUs shifted LRT fungal microbiota to Candida spp. dominated fungal profiles but antibiotic therapy did not. Compared to controls, Candida was part of fungal microbiota in LRT of ICU patients without pneumonia with and without antibiotic therapy (63% and 50% of total fungal genera) and of ICU patients with pneumonia with antibiotic therapy (73%) (p<0.05). No case of invasive candidiasis originating from Candida in the LRT was detected. There was no common bacterial microbiota profile associated or dissociated with Candida spp. in LRT. Colonizing and invasive Candida strains (from candidemic patients) did not match to certain clades withdrawing the presence of a particular pathogenic and invasive clade. The presence of Candida spp. in the LRT rather reflected rapidly occurring LRT dysbiosis driven by ICU related factors than was associated with invasive candidiasis.

Impact of selective digestive decontamination on respiratory tract Candida among patients with suspected ventilator-associated pneumonia. A meta-analysis

The purpose here is to establish the incidence of respiratory tract colonization with Candida (RT Candida) among ICU patients receiving mechanical ventilation within studies in the literature. Also of interest is its relationship with candidemia and the relative importance of topical antibiotic (TA) use as within studies of selective digestive decontamination (SDD) versus other candidate risk factors towards it. The incidence of RT Candida was extracted from component (control and intervention) groups decanted from studies of various TA and non-TA ICU infection prevention methods with summary estimates derived using random effects. A benchmark RT Candida incidence to provide overarching calibration was derived using (observational) groups from studies without any prevention method under study. A multi-level regression model of group level data was undertaken using generalized estimating equation (GEE) methods. RT Candida data were sourced from 113 studies. The benchmark RT Candida incidence is 1.3; 0.9-1.8 % (mean and 95 % confidence intervals). Membership of a concurrent control group of a study of SDD (p = 0.02), the group-wide presence of candidemia risk factors (p < 0.001), and proportion of trauma admissions (p = 0.004), but neither the year of study publication, nor membership of any other component group, nor the mode of respiratory sampling are predictive of the RT Candida incidence. RT Candida and candidemia incidences are correlated. RT Candida incidence can serve as a basis for benchmarking. Several relationships have been identified. The increased incidence among concurrent control groups of SDD studies cannot be appreciated in any single study examined in isolation.

Candida spp. airway colonization: A potential risk factor for Acinetobacter baumannii ventilator-associated pneumonia

This retrospective study was conducted to identify potential risk factors for Acinetobacter baumannii (A. baumannii) ventilator-associated pneumonia (VAP) and evaluate the association between Candida spp. airway colonization and A. baumannii VAP. Intensive care unit (ICU) patients who were on mechanical ventilation (MV) for ≥48 hours were divided into the following groups: patients with and without Candida spp. airway colonization; colonized patients receiving antifungal treatment or not; patients with A. baumannii VAP and those without VAP. Logistic regression analysis and propensity score matching were used to identify factors independently associated with A. baumannii VAP. Among 618 eligible patients, 264 (43%) had Candida spp. airway colonization and 114 (18%) developed A. baumannii VAP. Along with MV for ≥7 days (adjusted odds ratio [aOR] 8.9, 95% confidence intervals [95% CI] 4.9-15.8) and presence of a central venous catheter (aOR 3.2, 95% CI 1.1-9), Candida spp. airway colonization (aOR 2.6, 95% CI 1.6-4.3) was identified as an independent risk factor for A. baumannii VAP. Patients with Candida spp. airway colonization were more likely to develop A. baumannii VAP than non-colonized patients (23% vs 15%, P=.01 and 34% vs. 15%, P<.001 in propensity score-matched subgroups). Administration of antifungal agents was not associated with A. baumannii VAP (29% vs. 21%, P=.153) but with higher in-hospital mortality (53% vs. 39%, P=.037). Candida spp. airway colonization (43%) and A. baumannii VAP (18%) were common in ICU patients who were on mechanical ventilation for at least 48 hours. Candida spp. airway colonization was an independent risk factor for subsequent A. baumannii VAP.

Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

The isolation of Candida rugosa and Candida mesorugosa from clinical samples in Ghana

Members of the Candida rugosa species complex have been described as emerging fungal pathogens and are responsible for a growing number of Candida infections. In this communication we report the isolation of Candida rugosa and Candida mesorugosa in Ghana. To the best of our knowledge this is the first description of this species complex from a clinical setting in Africa.The isolates were identified on the basis of their rRNA gene internal transcribed spacer (ITS) sequences. For one isolate, obtained from sputum, the sequence grouped well with that of C. rugosa. Two other isolates from urine had sequences that grouped with Candida mesorugosa. Morphologically, C. rugosa formed white, wrinkled, and flat colonies on Sabouraud Dextrose Agar (SDA), whereas C. mesorugosa formed white, smooth colonies. On chromogenic medium, the isolates formed small, dry greenish-blue colonies with a pale or white border, similar to C. albicans. The C. rugosa isolate produced pseudohyphae in human serum and on CMA-Tween 80 agar. In contrast, the C. mesorugosa isolates did not generate pseudohyphae in human serum, but generated a few pseudohyphae with abundant blastoconidia on CMA-Tween 80 agar. Growth was observed at 37 °C and 42 °C but not at 45 °C.The two C. mesorugosa isolates had Minimum Inhibitory Concentrations (MICs) of 6 and 48 μg ml(-1) for fluconazole and are thus resistant. The C. rugosa isolate had an MIC of 24 μg ml(-1), indicative of resistance. All three isolates were susceptible to itraconazole and voriconazole (with respective MICs of < 0.125 μg ml(-1)).

Impact of Candida spp. isolation in the respiratory tract in patients with intensive care unit-acquired pneumonia

In immunocompetent patients with nosocomial pneumonia, the relationship between Candida spp. isolation in respiratory samples and outcomes or association with other pathogens is controversial. We therefore compared the characteristics and outcomes of patients with intensive care unit-acquired pneumonia (ICUAP), with or without Candida spp. isolation in the respiratory tract. In this prospective non-interventional study, we assessed 385 consecutive immunocompetent patients with ICUAP, according to the presence or absence of Candida spp. in lower respiratory tract samples. Candida spp. was isolated in at least one sample in 82 (21%) patients. Patients with Candida spp. had higher severity scores and organ dysfunction at admission and at onset of pneumonia. In multivariate analysis, previous surgery, diabetes mellitus and higher Simplified Acute Physiology Score II at ICU admission independently predicted isolation of Candida spp. There were no significant differences in the rate of specific aetiological pathogens, the systemic inflammatory response, and length of stay between patients with and without Candida spp. Mortality was also similar, even adjusted for potential confounders in propensity-adjusted multivariate analyses (adjusted hazard ratio 1.08, 95% CI 0.57-2.05, p 0.80 for 28-day mortality and adjusted hazard ratio 1.38, 95% CI 0.81-2.35, p 0.24 for 90-day mortality). Antifungal therapy was more frequently prescribed in patients with Candida spp. in respiratory samples but did not influence outcomes. Candida spp. airway isolation in patients with ICUAP is associated with more initial disease severity but does not influence outcomes in these patients, regardless of the use or not of antifungal therapy.

Animal models of polymicrobial pneumonia

Pneumonia is one of the leading causes of severe and occasionally life-threatening infections. The physiopathology of pneumonia has been extensively studied, providing information for the development of new treatments for this condition. In addition to in vitro research, animal models have been largely used in the field of pneumonia. Several models have been described and have provided a better understanding of pneumonia under different settings and with various pathogens. However, the concept of one pathogen leading to one infection has been challenged, and recent flu epidemics suggest that some pathogens exhibit highly virulent potential. Although "two hits" animal models have been used to study infectious diseases, few of these models have been described in pneumonia. Therefore the aims of this review were to provide an overview of the available literature in this field, to describe well-studied and uncommon pathogen associations, and to summarize the major insights obtained from this information.

The serum glucan level and pathological changes of antifungal treatment for lower respiratory tract infection of Candida albicans

Due to the fact that Candida albicans colonizes in the upper respiratory tracts of healthy people, whether or not its isolation from airway secretions is sufficient to warrant treatment remains controversial. The animal models of immunosuppressive rats with pulmonary candidiasis were established by the intratracheal inoculating suspensions of C. albicans, and the animals were divided into the following three groups: (1) antifungal treatment group, (2) saline control group, and (3) blank control group. We noted the following in our studies: (1) The fungal load of the saline control group gradually increased such that it was higher than those of the antifungal treated group and was significant from the fourth day of treatment (P < 0.01). (2) The serum (1,3)-β-D-glucan (BG) in the saline control group also gradually increased so that it was significantly higher than found with the treated group by the sixth day of treatment (P < 0.05), and in fact, the rank of pulmonary colony count and BG in the two groups at different time points showed an almost perfect linear correlation. (3) The median survival period of the rats in the antifungal treated group and saline control group was 15 and 8 days respectively, no rats died in the blank control group. (4) The lung lesions from the saline control group gradually became more aggravated than those in the antifungal treated group; no significant pathological changes were found in the blank control group. Antifungal treatment (micafungin) is capable of efficaciously decreasing the lung fungal burden, and continuous monitoring of BG is useful for the evaluation of therapeutic effect of antifungals. Infection of C. albicans with associated pathological damage implies the need for antifungal therapy.

Safety and efficacy of amphotericin-B deoxycholate inhalation in critically ill patients with respiratory Candida spp. colonization: a retrospective analysis

Background

Candida spp. are frequently cultured from the respiratory tract in critically ill patients. Most intensivists start amphotericin-B deoxycholate (ABDC) inhalation therapy to eradicate Candida spp. from the respiratory tract. However, the safety and efficacy of this treatment are not well established. The purpose of this study was to assess the safety and efficacy of ABDC inhalation for the treatment of respiratory Candida spp. colonization in critically ill patients.

Methods

All non-neutropenic patients admitted into the intensive care unit (ICU) of a university hospital from December 2010–2011, who had positive Candida spp. cultures of the respiratory tract for more than 1 day and required mechanical ventilation >48 h were retrospectively included. The decision to start ABDC inhalation had been made by attending intensivists on clinical grounds in the context of selective decontamination of the digestive tract. Infection characteristics and patient courses were assessed.

Results

Hundred and thirteen consecutive patients were studied. Fifty-one of them received ABDC inhalation and their characteristics at baseline and day 1 of respiratory colonization did not differ from those of colonized patients not receiving treatment (n = 62). The ABDC-treated group had a similar Candida spp. load but did not decolonize more rapidly as compared to untreated patients. The clinical pulmonary infection and lung injury scores did not decrease as in the untreated group. In a Cox proportional hazard model, the duration of mechanical ventilation was increased (P < 0.003) by ABDC treatment independently of other potential determinants and Candida spp. colonization. No differences in ventilator-associated pneumonia or in overall mortality (up to day 90) were observed.

Conclusion

Treatment of respiratory Candida spp. colonization in non-neutropenic critically ill patients by inhaled ABDC may not affect respiratory colonization but may increase duration of mechanical ventilation, because of direct toxicity of the drug on the lung.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0575-3) contains supplementary material, which is available to authorized users.

Epidemiology and outcomes of ventilator-associated pneumonia in northern Brazil: an analytical descriptive prospective cohort study

BACKGROUND

Ventilator-associated pneumonia (VAP) is considered the most common nosocomial infection in the intensive care unit (ICU), but its features are not fully known in many hospitals in Brazil. We identified clinical and epidemiological aspects associated with VAP in an intensive care unit (ICU) in a general public hospital in northern Brazil and performed an analytical descriptive prospective cohort study.

METHODS

We analyzed data from thirty-three patients who developed VAP while in the ICU. Clinical and epidemiological data of patients were obtained and tracheal secretions were submitted to culture. Microbial isolates were identified and evaluated for resistance against antimicrobial agents by using the automated Vitek 2 system.

RESULTS

The frequency of VAP was 26.2% in patients submitted to invasive mechanical ventilation for at least 48 hours, and death occurred in 78.8% of cases. Only the presence of comorbidity showed a significant association (P = 0.029) with death. The most commonly found bacteria were Pseudomonas aeruginosa, Acinetobacter spp., and Enterobacteriaceae. We also found a frequency of 54.5% of multiresistant bacteria associated with VAP, and previous antibiotic therapy was used in 97% of patients.

CONCLUSIONS

VAP in our ICU presented with a high frequency and was mainly caused by multiresistant bacteria. Implementation of rational protocols for the use of antibacterial agents and rapid delivery of culture and susceptibility test results are essential. This may help decrease VAP-related mortality rates by multiresistant bacteria in the ICU.

Impact of Candida species on clinical outcomes in patients with suspected ventilator-associated pneumonia

BACKGROUND

The significance of Candida species in respiratory tract (RT) secretions in critically ill patients is unclear.

METHODS

A retrospective analysis of the Canadian ventilator-associated pneumonia (VAP) trial was conducted. Only patients with suspected VAP whose initial cultures failed to grow any known pathogens were included. Using two fundamentally different statistical techniques that adjusted for important confounding variables, the clinical outcomes of patients with Candida species recovered from RT cultures were compared with patients whose RT cultures were not positive for Candida species.

RESULTS

RT cultures yielded no identifiable bacterial pathogens in 274 patients; 68 patients had Candida species in the RT alone, while 206 patients did not have Candida species recovered from any site. The unadjusted OR of hospital mortality for patients with Candida species was 2.9 (95% CI 1.6 to 5.2; P<0.001). The hazard ratio of time to hospital discharge was 0.54 (95% CI 0.38 to 0.77; P=0.001). Logistic regression analysis demonstrated that age, Acute Physiology score and Chronic Health Evaluation (APACHE) II score, primary diagnosis of respiratory failure, two or more comorbidities and Candida species were independently associated with increased hospital mortality. Similar trends were observed with time to hospital discharge. The association between Candida species and increased mortality remained after controlling for potential confounders using both propensity score stratification and multivariable modelling approaches.

CONCLUSIONS

Patients with suspected VAP, in whom no bacterial pathogen was identified and in whom Candida species were isolated from RT cultures, exhibited a greater burden of illness compared with similar patients without Candida. Whether Candida species colonization of RT secretions is a marker of disease severity or actually contributes to poorer clinical outcomes remains unclear.

[Invasive fungal infection in critically ill patients]

The most common organism implicated in fungal infections in the critically ill patients is Candida spp. C. albicans continues to be the species that causes the largest number of invasive candidiasis. In critically ill patients, Candida spp. are frequently isolated in non-sterile sites. Candida colonization is documented in nearly 60% of non-neutropenic critically ill patients staying more than one week in the ICU. However, only 5% of colonized patients will develop invasive candidiasis. The diagnosis of invasive non-candidemic candidiasis remains elusive in the majority of the patients. Candida in a blood culture should never be viewed as a contaminant and should always prompt treatment initiation. Patients with multifocal colonization with a Candida score >3 should also receive antifungal therapy. Fluconazole is reserved for non-severely ill patients without recent exposure to azoles. The use of an echinocandin is recommended for hemodynamically unstable patients or with a history of recent fluconazole exposure.

Ventilator-associated pneumonia: a comprehensive review

Ventilator-associated pneumonia (VAP) is the most frequent and severe infection acquired in the intensive care unit, leading to prolonged mechanical ventilation and excess mortality. This article reviews the different aspects of VAP, such as risk factors, causative agents, and approaches to diagnosis, treatment, and prevention. Several aspects of VAP are still considered controversial.

Diagnosis and therapy of Candida infections: joint recommendations of the German Speaking Mycological Society and the Paul-Ehrlich-Society for Chemotherapy

Invasive Candida infections are important causes of morbidity and mortality in immunocompromised and hospitalised patients. This article provides the joint recommendations of the German-speaking Mycological Society (Deutschsprachige Mykologische Gesellschaft, DMyKG) and the Paul-Ehrlich-Society for Chemotherapy (PEG) for diagnosis and treatment of invasive and superficial Candida infections. The recommendations are based on published results of clinical trials, case-series and expert opinion using the evidence criteria set forth by the Infectious Diseases Society of America (IDSA). Key recommendations are summarised here: The cornerstone of diagnosis remains the detection of the organism by culture with identification of the isolate at the species level; in vitro susceptibility testing is mandatory for invasive isolates. Options for initial therapy of candidaemia and other invasive Candida infections in non-granulocytopenic patients include fluconazole or one of the three approved echinocandin compounds; liposomal amphotericin B and voriconazole are secondary alternatives because of their less favourable pharmacological properties. In granulocytopenic patients, an echinocandin or liposomal amphotericin B is recommended as initial therapy based on the fungicidal mode of action. Indwelling central venous catheters serve as a main source of infection independent of the pathogenesis of candidaemia in the individual patients and should be removed whenever feasible. Pre-existing immunosuppressive treatment, particularly by glucocorticosteroids, ought to be discontinued, if feasible, or reduced. The duration of treatment for uncomplicated candidaemia is 14 days following the first negative blood culture and resolution of all associated symptoms and findings. Ophthalmoscopy is recommended prior to the discontinuation of antifungal chemotherapy to rule out endophthalmitis or chorioretinitis. Beyond these key recommendations, this article provides detailed recommendations for specific disease entities, for antifungal treatment in paediatric patients as well as a comprehensive discussion of epidemiology, clinical presentation and emerging diagnostic options of invasive and superficial Candida infections.

Genetic relationships between Candida albicans strains isolated from dental plaque, trachea, and bronchoalveolar lavage fluid from mechanically ventilated intensive care unit patients

Candida albicans often resides in the oral cavity of healthy humans as a harmless commensal organism. This opportunistic fungus can cause significant disease in critically ill patients, such as those undergoing mechanical ventilation in the intensive care unit (ICU) having compromised local airway defense mechanisms. The goal of this study was to determine the intra- and inter-patient genetic relationship between strains of C. albicans recovered from dental plaque, tracheal secretions, and the lower airway by bronchoalveolar lavage of patients undergoing mechanical ventilation. Three pulsed-field gel electrophoresis (PFGE) typing methods were used to determine the genetic relatedness of the C. albicans strains, including electrophoretic karyotyping (EK) and restriction endonuclease analysis of the genome using SfiI (REAG-S) and BssHII (REAG-B). The C. albicans isolates from dental plaque and tracheo-bronchial sites from the same patient were genetically indistinguishable and retained over time, whereas strains from different patients usually separated into different genotypes. Among the three methods, REAG-B proved to be the most discriminatory method to differentiate isolates. The finding of genetically similar strains from the oral and tracheo-bronchial sites from the same patient supports the notion that the oral cavity may serve as an important source for C. albicans spread to the trachea and lung of mechanically ventilated patients.

Viral colonization in intubated patients: initial pathogen pattern and follow-up

INTRODUCTION

Colonization of the lower respiratory tract is an independent risk factor for ventilator-associated pneumonia. Little is known about the frequency of viral colonization on intubation and during mechanical ventilation.

METHODS

Overall, 65 eligible intubated patients with no initial signs of pulmonary infection were studied over a period of up to 7 days. Tracheobronchial aspirates were taken: (i) within 48 h after intubation; and (ii) when clinical signs of nosocomial tracheobronchitis were present, before extubation, or after 7 days. Presence of respiratory viruses was investigated using quantitative polymerase chain reaction.

RESULTS

Patients were 67 +/- 11 years old and had been in hospital for 5.1 +/- 8.4 days when intubated (major cause for intubation: cardio-pulmonary resuscitation 25/65, 38%). The average Acute Physiology and Chronic Evaluation II score was 27.3 +/- 4.9. Microbiology detected Candida spp. (17/65; 26%) and Staphylococcus aureus (methicillin sensitive: 11/65; 17%; methicillin resistant: 3/65; 5%) and only few respiratory viruses (4/65, 6%). Thirty-eight percent of the samples (25/65) were sterile. At the given endpoints, 27/65 (42%) patients were available for follow-up and only one aspirate became positive for respiratory syncytial virus (RSV).

CONCLUSIONS

After endotracheal intubation, fungi, but not viruses were most frequently isolated. Only one patient acquired RSV, therefore colonization with respiratory viruses does not seem to play a major role early after intubation.

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.

Candida and the paediatric lung

Although systemic candidosis is common in hospitalised children, Candida involvement of lung parenchyma is rare and usually perceived only at autopsy. The purpose of this article was to review the evidence regarding lung involvement in Candida infections, with special attention to paediatric patients. Primary Candida pneumonia is rare and usually associated with aspiration of oropharyngeal contents. The majority of cases of Candida pneumonia are secondary to haematological dissemination of Candida organisms from a distant site, usually the gastrointestinal tract or the skin. The diagnosis of pulmonary candidosis is difficult because there is no specific clinical or radiological presentation. In addition, the presence of Candida in sputum or other respiratory specimens mostly represents contamination. A definitive diagnosis of Candida pneumonia requires histopathologic proof of lung invasion in association with inflammation. Children can also be affected by pulmonary allergic reactions caused by Candida species. Treatment of Candida pneumonia is essentially the same as for candidaemia. Preliminary evidence suggests that patients with severe asthma sensitised to Candida species may also benefit from antifungal drugs.

Clinical practice guidelines for the management of candidiasis: 2009 update by the Infectious Diseases Society of America

Guidelines for the management of patients with invasive candidiasis and mucosal candidiasis were prepared by an Expert Panel of the Infectious Diseases Society of America. These updated guidelines replace the previous guidelines published in the 15 January 2004 issue of Clinical Infectious Diseases and are intended for use by health care providers who care for patients who either have or are at risk of these infections. Since 2004, several new antifungal agents have become available, and several new studies have been published relating to the treatment of candidemia, other forms of invasive candidiasis, and mucosal disease, including oropharyngeal and esophageal candidiasis. There are also recent prospective data on the prevention of invasive candidiasis in high-risk neonates and adults and on the empiric treatment of suspected invasive candidiasis in adults. This new information is incorporated into this revised document.

Saline instillation before tracheal suctioning decreases the incidence of ventilator-associated pneumonia

OBJECTIVES

To compare the incidence of ventilator-associated pneumonia (VAP) with or without isotonic saline instillation before tracheal suctioning. As a secondary objective, we compared the incidence of endotracheal tube occlusion and atelectasis.

DESIGN

Randomized clinical trial.

SETTING AND PATIENTS

The study was conducted in a medical surgical intensive care unit of an oncologic hospital. We selected consecutive patients needing mechanical ventilation for >72 hrs. Patients were allocated into two groups: a saline group that received instillation of 8 mL of saline before tracheal suctioning and a control group which did not. VAP was diagnosed based on clinical suspicion and confirmed by bronchoalveolar lavage quantitative culture. The incidence of atelectasis on daily chest radiography and endotracheal tube occlusions were recorded. The sample size was calculated to a power of 80% and a type I error probability of 5%.

MEASUREMENTS AND MAIN RESULTS

One hundred thirty patients were assigned to the saline group and 132 to the control group. The baseline demographic variables were similar between groups. The rate of clinically suspected VAP was similar in both groups. The incidence of microbiological proven VAP was significantly lower in the saline group (23.5% x 10.8%; p = 0.008) (incidence density/1.000 days of ventilation 21.22 x 9.62; p < 0.01). Using the Kaplan-Meier curve analysis, the proportion of patients remaining without VAP was higher in the saline group (p = 0.02, log-rank test). The relative risk reduction of VAP in the saline instillation group was 54% (95% confidence interval, 18%-74%) and the number needed to treat was eight (95% confidence interval, 5-27). The incidence of atelectases and endotracheal tube occlusion were similar between groups.

CONCLUSIONS

Instillation of isotonic saline before tracheal suctioning decreases the incidence of microbiological proven VAP.

Is Candida really a threat in the ICU?

PURPOSE OF REVIEW

The epidemiological and clinical relevance of Candida in the ICU is reviewed. Three issues were appraised. First is the prevalence of Candida. Second is the relevance of nonblood cultures positive for Candida and multisite colonization. Third is the importance of invasive candidiasis in terms of mortality.

RECENT FINDINGS

The diagnosis of invasive candidiasis remains problematic in nonblood cultures. Consequently, the true prevalence of invasive candidiasis is difficult to assess. Another result of the complicated diagnosis is the risk for delayed antifungal therapy in case of systemic Candida infection. Therefore, pre-emptive therapy has become increasingly popular in high-risk patients.

SUMMARY

Candida spp. cause a minority of nosocomial bloodstream infections ( approximately 4-9%). Yet, delayed initiation of appropriate antifungal therapy results in significant attributable mortality. Given the inability to efficiently discriminate colonization from invasive candidiasis, this is a problematic issue. The presence of Candida in tracheal aspirates, urine cultures or wound swabs frequently reflects colonization. Yet, multisite colonization frequently precedes systemic invasion. As such, multisite Candida colonization is a crucial element in the decision to start pre-emptive therapy. However, the predictive value of multisite colonization in the absence of an overt risk profile for invasive candidiasis appears to be low.

Evidence-based algorithms for diagnosing and treating ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is widely recognized as a serious and common complication associated with high morbidity and high costs. Given the complexity of caring for heterogeneous populations in the intensive care unit (ICU), however, there is still uncertainty regarding how to diagnose and manage VAP.

OBJECTIVE

We recently conducted a national collaborative aimed at reducing health care-associated infections in ICUs of hospitals operated by the Hospital Corporation of America (HCA). As part of this collaborative, we developed algorithms for diagnosing and treating VAP in mechanically ventilated patients. In the current article, we (1) review the current evidence for diagnosing VAP, (2) describe our approach for developing these algorithms, and (3) illustrate the utility of the diagnostic algorithms using clinical teaching cases.

DESIGN

This was a descriptive study, using data from a national collaborative focused on reducing VAP and catheter-related bloodstream infections.

SETTING

The setting of the study was 110 ICUs at 61 HCA hospitals.

INTERVENTION

None.

MEASUREMENTS AND RESULTS

We assembled an interdisciplinary team that included infectious disease specialists, intensivists, hospitalists, statisticians, critical care nurses, and pharmacists. After reviewing published studies and the Centers for Disease Control and Prevention VAP guidelines, the team iteratively discussed the evidence, achieved consensus, and ultimately developed these practical algorithms. The diagnostic algorithms address infant, pediatric, immunocompromised, and adult ICU patients.

CONCLUSIONS

We present practical algorithms for diagnosing and managing VAP in mechanically ventilated patients. These algorithms may provide evidence-based real-time guidance to clinicians seeking a standardized approach to diagnosing and managing this challenging problem.

Interaction de Pseudomonas aeruginosa avec Candida albicans dans les voies respiratoires: de la physiopathologie à une perspective thérapeutique

Several studies evidenced a pathogenic interaction between P. aeruginosa and C. albicans. P. aeruginosa is one of the most frequent microorganisms responsible for ventilator-associated pneumonia (VAP) and C. albicans usually colonize tracheo-bronchial tract of patients undergoing mechanical ventilation in the intensive care unit. In vitro, P. aeruginosa exploits filamentous fungi resulting in fungal killing and limitation of C. albicans growth in the host. Biofilm also play an important role as a persistent source of infectious material for recurrent episodes of VAP. Indeed, Candida spp and P. aeruginosa are the most common pathogens retrieved from endotracheal tube biofilm and tracheal secretions in patients with VAP. Finally, it has been demonstrated that previous tracheo-bronchial C. albicans colonization enhanced the incidence of P. aeruginosa pneumonia in a murine model. A recent study performed in patients requiring intubation and mechanical ventilation identified Candida spp tracheo-bronchial colonization as a risk factor for P. aeruginosa VAP. In addition, a retrospective study suggested that antifungal treatment might reduce P. aeruginosa VAP or tracheo-bronchial colonization in intubated patients with Candida spp tracheo-bronchial colonization. These interactions have major environmental and medical consequences. Experimental studies providing a better understanding of the mechanisms of interaction and clinical studies evaluating the necessity of a antifungal treatment might improve the management of these opportunistic infections.

Guidelines for evaluation of new fever in critically ill adult patients: 2008 update from the American College of Critical Care Medicine and the Infectious Diseases Society of America

OBJECTIVE

To update the practice parameters for the evaluation of adult patients who develop a new fever in the intensive care unit, for the purpose of guiding clinical practice.

PARTICIPANTS

A task force of 11 experts in the disciplines related to critical care medicine and infectious diseases was convened from the membership of the Society of Critical Care Medicine and the Infectious Diseases Society of America. Specialties represented included critical care medicine, surgery, internal medicine, infectious diseases, neurology, and laboratory medicine/microbiology.

EVIDENCE

The task force members provided personal experience and determined the published literature (MEDLINE articles, textbooks, etc.) from which consensus was obtained. Published literature was reviewed and classified into one of four categories, according to study design and scientific value.

CONSENSUS PROCESS

The task force met twice in person, several times by teleconference, and held multiple e-mail discussions during a 2-yr period to identify the pertinent literature and arrive at consensus recommendations. Consideration was given to the relationship between the weight of scientific evidence and the strength of the recommendation. Draft documents were composed and debated by the task force until consensus was reached by nominal group process.

CONCLUSIONS

The panel concluded that, because fever can have many infectious and noninfectious etiologies, a new fever in a patient in the intensive care unit should trigger a careful clinical assessment rather than automatic orders for laboratory and radiologic tests. A cost-conscious approach to obtaining cultures and imaging studies should be undertaken if indicated after a clinical evaluation. The goal of such an approach is to determine, in a directed manner, whether infection is present so that additional testing can be avoided and therapeutic decisions can be made.

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.

[Invasive candidiasis in the critically ill, patient non-neutropenic]

Invasive candidiasis can occur in immunosuppressed patients as well as in critically ill, non-immunocompromised patients and is associated with high mortality (20-40 %). Intestinal Candida colonisation is an important source for invasive candidiasis. Risk factors for the development of invasive candidiasis include presence of an intravascular device, organ dysfunction, impaired mucosal or skin barrier function, therapy with antacids or corticosteroids, prolonged stay at the ICU, total parenteral nutrition and prolonged antibiotic therapy. Among patients with invasive candidiasis, antifungal treatment should be started without delay. Antifungal prophylaxis is currently not recommended in critically ill, non-immunocompromised patients.

[Clinical spectrum of invasive candidiasis in critically ill non-neutropenic patients]

Invasive Candida spp. infections in non-neutropenic critically ill patients admitted to intensive care units can be classified as focal and systemic. Both types of infection usually occur after episodes of candidemia, although some focal infections may be of exogenous development, like those occurring after trauma or be device-related.The clinical spectrum of invasive Candida spp. infections includes focal urinary tract, abdominal, ocular, respiratory tract, renal and hepato-biliary infections, as well as systemic infections like candidemia and acute systemic candidiasis with multiorgan involvement after hematogenous seeding. Candida spp. isolates in "significant" samples, like synovial fluid, cerebrospinal fluid and blood cultures, represent true infection. However, the diagnosis of invasive infection based on "non-significant" samples, like surgical drains and digestive tract exudates, requires additional criteria. The total number of isolates from different sites, the presence of risk factors, the clinical host response, as well as severity of illness need to be taken into account for the diagnosis of invasive candidiasis. The clinical signs of systemic infection due to Candida spp. are completely non-specific and cannot be differentiated from bacterial peritonitis, urinary tract infection or bacteremia. These infections may be associated with signs of sepsis,severe sepsis, septic shock or multiorgan dysfunction. In the future clinical multicentre observational and interventional studies are necessary to reach agreement on clinical definitions and classification of invasive Candida spp. infections in critically ill non-immunocompromised patients.

Ventilator-associated pneumonia: diagnosis, treatment, and prevention

While critically ill patients experience a life-threatening illness, they commonly contract ventilator-associated pneumonia. This nosocomial infection increases morbidity and likely mortality as well as the cost of health care. This article reviews the literature with regard to diagnosis, treatment, and prevention. It provides conclusions that can be implemented in practice as well as an algorithm for the bedside clinician and also focuses on the controversies with regard to diagnostic tools and approaches, treatment plans, and prevention strategies.

Candida colonization of the respiratory tract and subsequent pseudomonas ventilator-associated pneumonia

BACKGROUND

Recovery of Candida from the respiratory tract of a critically ill patient receiving mechanical ventilation (MV) usually indicates colonization rather than infection of the respiratory tract. However, interactions between Candida and bacteria, particularly Pseudomonas, have been reported. Thus, Candida colonization of the respiratory tract may predispose to bacterial ventilator-associated pneumonia (VAP).

METHODS

In a multicenter study of immunocompetent critically ill patients receiving MV for > 2 days, we compared the incidence of pneumonia in patients with and without (exposed/unexposed) respiratory-tract Candida colonization, matched on study center, admission year, and MV duration.

RESULTS

Over the 4-year study period, of the 803 patients meeting study inclusion criteria in the six study centers, 214 patients (26.6%) had respiratory tract Candida colonization. Candida albicans was the most common species (68.7%), followed by Candida glabrata (20.1%) and Candida tropicalis (13.1%). Extrapulmonary Candida colonization was more common in exposed patients (39.7% vs 8.3%, p = 0.01). Exposed patients had longer ICU and hospital stays but similar mortality to unexposed patients. The matched exposed/unexposed nested cohort study identified bronchial Candida colonization as an independent risk factor for pneumonia (24.1% vs 17.6%; adjusted odds ratio [OR], 1.58; 95% confidence interval [CI], 0.94 to 2.68; p = 0.0860); the risk increase was greatest for Pseudomonas pneumonia (9% vs 4.8%; adjusted OR, 2.22; 95% CI, 1.00 to 4.92; p = 0.049).

CONCLUSIONS

Candida colonization of the respiratory tract is common in patients receiving MV for > 2 days and is associated with prolonged ICU and hospital stays, and with an increased risk of Pseudomonas VAP.

Candida sp. isolated from bronchoalveolar lavage: clinical significance in critically ill trauma patients

OBJECTIVE

Based on limited data, Candida sp. isolates from bronchoalveolar lavage (BAL) cultures in immunocompetent patients are thought to be contaminants rather than pathogens. The objective of this study was to determine the clinical significance of Candida sp. isolated from BAL cultures in critically ill trauma patients.

DESIGN AND SETTING

Retrospective study in a level 1 trauma intensive care unit.

PATIENTS AND PARTICIPANTS

All patients with Candida sp. isolated from BAL cultures over a 3-year period; 85 Candida positive BAL cultures from 62 patients were studied.

MEASUREMENTS AND RESULTS

The primary outcomes were the incidence of Candida sp. in BAL, antifungal use, course of the possible infection, and mortality. Of 1077 BAL cultures 85 (8%) grew Candida sp., representing 64 episodes of possible Candida sp. ventilator-associated pneumonia. No colony counts exceeded the diagnostic threshold for bacterial VAP (>or=10(5) cfu/ml). Only 2 of 64 episodes (3%) were treated with systemic antifungals. Three other episodes (5%) were treated because of concomitant therapy for Candida sp. at other sites. The majority of episodes were not treated with antifungals and were considered contaminants (59/64, 92%). No patients developed subsequent candidemia, and most follow-up BALs (74%) were negative for Candida sp. Overall mortality (17%) was similar to previous patients with similar severity of injury at the study center (18%).

CONCLUSIONS

The results of this study suggest that isolation of Candida sp. from BAL in quantities below the diagnostic threshold for VAP in this population does not require antifungal therapy.