Fungal infection in the intensive care unit

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.

Antifungal treatment strategies in patients with haematological diseases or cancer: from prophylaxis to empirical, pre-emptive and targeted therapy

Immunocompromised patients have a high risk for invasive fungal diseases (IFDs). These infections are mostly life-threatening and an early diagnosis and initiation of appropriate antifungal therapy are essential for the clinical outcome. Empirical treatment is regarded as the standard of care for granulocytopenic patients who remain febrile despite broad-spectrum antibiotics. However, this strategy can bear a risk of overtreatment and subsequently induce toxicities and unnecessary treatment costs. Pre-emptive antifungal therapy is now increasingly used to close the time gap between delayed initiation for proven disease and empirical treatment for anticipated infection without further laboratory or radiological evidence of fungal disease. Currently, some new non-invasive microbiological and laboratory methods, like the Aspergillus-galactomannan sandwich-enzyme immunoassay (Aspergillus GM-ELISA), 1,3-β-D-glucan assay or PCR techniques have been developed for a better diagnosis and determination of target patients. The current diagnostic approaches to fungal infections and the role of the revised definitions for invasive fungal infections, now IFDs, will be discussed in this review as well as old and emerging approaches to empirical, pre-emptive and targeted antifungal therapies in patients with haemato-oncological malignancies.

Outcomes of hematopoietic stem cell transplant patients who received continuous renal replacement therapy in a pediatric oncology intensive care unit

OBJECTIVES

To assess the long-term benefits of continuous renal replacement therapy (CRRT) in this patient population and to analyze factors associated with survival. Hematopoietic stem cell transplantation is being utilized as curative therapy for a variety of disorders. However, organ dysfunction is commonly associated with this therapy. Continuous renal replacement therapy (CRRT) is increasingly being used in the treatment of this multiorgan dysfunction.

DESIGN

Retrospective cohort study.

SETTING

A free-standing, tertiary care, pediatric oncology hospital.

PATIENTS

Twenty-nine allogeneic hematopoietic stem cell transplantation patients who underwent 33 courses of CRRT in the intensive care unit between January 2003 and December 2007.

INTERVENTIONS

Cox proportional hazards regressions models were used to examine the relationship between demographic and clinical variables and length of survival.

MEASUREMENTS AND MAIN RESULTS

The median length of survival post CRRT initiation was 31 days; only one patient survived >6 mos. Factors associated with increased risk of death included: higher bilirubin and blood urea nitrogen levels before and at 48 hrs into CRRT, lower Pao2/Fio2 ratios at 48 hrs of CRRT, and higher C-reactive protein levels, as well as lower absolute neutrophil counts at CRRT end.

CONCLUSION

In this single-center study, CRRT was not associated with long-term survival in pediatric allogeneic hematopoietic stem cell transplantation patients. Clinical data exist, both before and during CRRT, that may be associated with length of survival. Lower C-reactive protein levels at CRRT end were associated with longer survival, suggesting that the ability to attenuate inflammation during CRRT may afford a survival advantage. These findings require confirmation in a prospective study.

Prophylactic Fluconazole Does Not Improve Outcome in Patients with Purulent and Fecal Peritonitis due to Lower Gastrointestinal Perforation

The benefit of anticandida treatment in addition to standard antibiotic therapy in the presence of perforation/leakage of the lower gastrointestinal tract (LGIT) is still controversial. We retrospectively assessed the clinical effects of empiric anticandida treatment in patients with LGIT perforation who had undergone exploratory laparotomy due to perforated/leaking bowel or appendix between 1999 and 2004, including generalized fecal/purulent peritonitis. Two groups of patients emerged: those receiving empiric anticandida treatment (fluconazole, n = 24) and those who did not (n = 77). All the fluconazole-treated and 40/77 nonfluconazole-treated patients required intensive care unit care and were the subject of this assessment. Postoperative Candida infection and mortality rates were similar in the critically-ill fluconazole-treated and nontreated patients (4% vs 7%, 21% vs 22.5%, respectively, P = NS); resistant candidiasis rates were also similar. Hospital and intensive care unit stays were longer in the treated group, however not reaching statistical difference (26.5 ± 18 vs 21.4 ± 18.3 days, 14.8 ± 14.2 vs 9.3 ± 14.1 days, respectively). The rates of morbidity, pneumonia, and multiorgan failure were significantly higher ( P < 0.05) in the treated patients (87% vs 63%, 37% vs 7.5%, and 58% vs 35%, respectively). Empiric fluconazole in patients with peritonitis associated with LGIT perforation did not improve patients’ outcome compared with those without empiric treatment.

Isolation of Aspergillus in critically ill patients: a potential marker of poor outcome

OBJECTIVE

Recent reports have suggested a rising incidence of pulmonary aspergillosis in intensive care unit (ICU) patients. The aim of this study was to determine the clinical significance of isolating Aspergillus from respiratory samples of critically ill patients.

DESIGN

Retrospective review of medical records.

SETTING

Tertiary medical center that has a large cancer center.

PATIENTS

All patients admitted to the ICU between January 1998 and August 2004, in whom Aspergillus was isolated from respiratory samples or lung tissue.

INTERVENTION

None.

RESULTS

The charts of 104 patients were reviewed. Aspergillus was isolated for a mean of 6.6 days after ICU admission. Thirty-three percent of patients had hematological malignancy, 10% had absolute neutropenia, 14% had bone marrow transplant, 11% had HIV infection, and 22% had chronic obstructive pulmonary disease. Upon admission to ICU, 79%, 43%, and 19% were on antibiotics, corticosteroids, or immunosuppressive therapy, respectively. Ninety percent of patients required mechanical ventilation. The mean Acute Physiologic and Chronic Health Evaluation II score on ICU admission was 20.6, with predicted mortality of 35.5%. However, the actual ICU mortality rate for the cohort was 50%. Twenty-eight percent of patients were diagnosed with probable or definite invasive pulmonary aspergillosis, and 72% had Aspergillus colonization. On univariate analysis, the significant clinical differences between the 2 groups were the presence of neutropenia (P < .05), immunosuppressants (P < .05), antibiotics (P < .05), or bone marrow transplant (P < .05). The differences in Acute Physiologic and Chronic Health Evaluation II score, the need for mechanical ventilation, ICU length of stay, and ICU mortality were not statistically significant. On multivariate analysis, the following factors were independently associated with invasive diseases, bone marrow transplantation (P < .01), hematological malignancy (P = .02), and broad-spectrum antibiotics (P = .02).

CONCLUSION

Isolation of Aspergillus in critically ill patients is a poor prognostic marker and is associated with high mortality irrespective of invasion or colonization. Those who are neutropenic, on immunosuppressive therapy, on broad-spectrum antibiotics, or had bone marrow transplantation are more likely to have invasive pulmonary aspergillosis.

Candidosis in the intensive care unit: a 20-year survey

Deep-seated candidosis is a major problem in critically ill patients. Colonization with candida has been identified as an important independent risk factor for the development of candidaemia. Since the 1980s routine surveillance cultures have been performed on patients admitted for six or more days to the 'E. Vecla' intensive care unit (ICU) of the IRCCS Ospedale Maggiore di Milano. Colonization was observed on admission to the ICU in 59 of 117 (50%) patients in 2000 and 10 others developed colonization during their stay on the unit. A similar colonization rate was found in a survey performed 16 years earlier. The incidence of non-albicans Candida species, however, increased in 2000. In particular, 24 patients were culture positive for Candida glabrata at some point during their hospital stay, whereas this species was isolated from only one patient in 1983-1984. Antifungal susceptibility testing performed by Sensititre Yeast One revealed no resistance among 19 C. albicans strains tested. In contrast, fluconazole resistance was observed in two of 39 (5%) C. glabrata isolates from 23 patients. In the period 1983-2002, 28 candida bloodstream infections were identified and 12 were considered to be ICU-acquired (2.6/1000 hospitalized patients; 0.33/1000 patient days). The low rate of ICU-acquired candidaemia despite the inclusion of severely compromised patients in this study confirms the usefulness of routine mycological surveillance in preventing deep-seated candidosis.

Epidemiología de la candidemia en UCI

During the last decades there has been an important increase in the incidence of fungal infections. These infections are common in the setting of Intensive Care Units (ICU), where the prevalence of high-risk patients is important. In this review we discuss the incidence of candidemia in ICUs, as well as the mortality and economic impact. The participation of non-Candida albicans Candida species in the etiology of these infections is currently increasing.

The use of topical nonabsorbable gastrointestinal antifungal prophylaxis to prevent fungal infections in critically ill immunocompetent patients: A meta-analysis

OBJECTIVE

To investigate the preventive effect of topical nonabsorbable gastrointestinal antifungal prophylaxis on the incidence of fungal infection in critically ill immunocompetent patients.

DATA SOURCE

Randomized controlled studies involving critically ill pediatric and adult patients in different languages from the Cochrane Controlled Trial Register (2004, issue 1), EMBASE, and MEDLINE databases (1966 to 30 April 2004) were included. Studies evaluating absorbable antifungal prophylaxis were excluded. Two reviewers assessed the quality of the studies and performed data extraction independently.

DATA

Amphotericin B and nystatin were used as the nonabsorbable antifungal prophylaxis in the 15 studies included in this meta-analysis. Ten studies used a concomitant systemic antibiotic and four more studies used concomitant topical nonabsorbable antibiotics in the treatment group. Only one study compared topical nonabsorbable antifungal prophylaxis alone with placebo. The total incidence of fungal infections (relative risk [RR], 0.30; 95% confidence interval [CI], 0.18-0.48; p < .00001; extent of inconsistency [I(2)] = 0%) and proportion of patients with fungal infection (RR, 0.50; 95% CI, 0.28-0.87; p = .02; I(2) = 0%) were significantly reduced with topical nonabsorbable antifungal prophylaxis. The incidence of fungal urinary tract infection was significantly reduced (RR, 0.27; 95% CI, 0.10-0.74; p = .01; I(2)= 0%) but not fungal pneumonia (RR, 0.57; 95% CI, 0.28-1.16; p = .12; I(2)= 0%). Fungemia and catheter-related fungal sepsis were rare and not significantly reduced with nonabsorbable antifungal prophylaxis. The results remained unchanged in the sensitivity analyses after exclusion of studies with unclear study quality or exclusion of the contribution of fungal urinary tract infections to the total incidence of fungal infections.

CONCLUSIONS

In critically ill immunocompetent patients who are at high risk of fungal infection, topical nonabsorbable gastrointestinal antifungal prophylaxis was associated with a reduced incidence of urinary fungal infections and a trend toward reduction in respiratory fungal infections and fungemia. Limitations in study data are such that many of these infections may have represented superficial infections of uncertain clinical importance; a large, randomized, controlled trial is needed to assess the cost-effectiveness and safety of topical nonabsorbable antifungal prophylaxis in critically ill patients.

Management of invasive candidiasis in critically ill patients

Candida species have become predominant pathogens in critically ill patients. In this population, invasive candidiasis is associated with a poor prognosis but adequate management can limit the attributable mortality. Adequate management, however, is hampered by a problematic diagnosis as the clinical picture of invasive disease is non-specific and blood cultures have a low sensitivity. Moreover, it is often hard to differentiate colonisation from infection and many critically ill patients are heavily colonised with Candida species, especially when receiving broad-spectrum antibacterials. The question of which antifungal agent to choose has become more complex as the development of new drugs raises promising expectations. Until the 1980s therapy for invasive candidiasis was limited to amphotericin B, but with the advent of new antifungal agents, such as azoles and echinocandins, less toxic therapeutic options are possible and doors have opened towards prevention and optimised therapy in the case of documented candidiasis. Through the arrival of these new antifungal agents, a range of therapeutic strategies for the management of invasive candidiasis has been developed: antifungal prophylaxis, pre-emptive therapy, and empirical and definitive antifungal therapy. Each of these strategies has a specific target population, as defined by specific underlying conditions and/or individual risk factors. Antifungal prophylaxis, in order to prevent candidal infection, is based on the type of underlying diseases with a high risk for invasive candidiasis. Individual risk factors are not taken into account. Potential indications are bone marrow transplantation, liver transplantation, recurrent gastrointestinal perforations or leakages, and surgery for acute necrotising pancreatitis. Pre-emptive therapy is also a preventive strategy. It can be recommended on the basis of an individual risk profile including overt candidal colonisation. Empirical therapy is started in patients with a risk profile for invasive candidiasis. It is recommended in the presence of clinical signs of infection, deteriorating clinical parameters, or a clinical picture of infection not responding to antibacterials but in the absence of a clear causative pathogen. Definitive antifungal therapy is defined as therapy in patients with documented invasive infection. The main goal is to maintain a balance between optimal prevention and timely initiation of therapy on one hand, and to minimise selection pressure in order to avoid a shift towards less susceptible Candida species on the other hand.

[Recurrent Candida sepsis with prolonged respiratory failure and severe liver dysfunction]

Systemic mycoses, especially pulmonary diseases and septicemia are observed increasingly at intensive care units. Essential risk factors for development of candidosis are the expanded use of antibiotics and immunocompromised patients, caused either as a result of a severe underlying disease or iatrogenically induced after organ transplantation. Candida albicans is the most frequent pathogen in microbiological findings. Blood cultures are only positive in massive fungemia. We report a 50-year-old patient with recurrent Candida-septicemia: rupture of the distal esophagus after dilatation because of cardiac achalasia with mediastinal emphysema and mediastinitis. Severe acute respiratory distress syndrome after aspiration with septic shock and acute renal failure at the beginning. Long-term mechanical ventilation, continuous renal replacement therapy and multifarious antibiotic therapy. Early microbiological samples of several positive blood cultures and bronchoalveolar lavages revealed the presence of Candida albicans. In the further clinical course, detection of Pseudomonas species in bronchoalveolar lavages and Staphylococci as well as Enterococci in a number of positive blood cultures. Later on development of a severe liver dysfunction with test results that showed an intrahepatic cholestasis. Because of coagulation failure commencement of artificial liver support with the MARS-system (molecule adsorbent recirculating system). Decrease of high bilirubin levels was accompanied by improvement of clinical condition of the patient. In the following course, repeated severe systemic infections with phases of septicemia or rather septic shock and detection of Candida in several positive blood cultures and bronchoalveolar lavages. In each case increasing bilirubin levels with signs of intrahepatic cholestasis and each time improvement with antimycotic therapy (voriconazol, caspofungin and fluconazol). The patient showed more and more signs of immunodeficiency in the sequel. The clinical appearance of candidosis is manifold. Systemic Candida infections are frequent in patients with immunodeficiency. A recurrent Candida septicemia with prolonged respiratory failure and severe liver dysfunction in form of cholestatic hepatosis, that improved several times with antimycotic therapy in combination with evidence based intensive care measures and artificial organ support is a comparatively rare event.

[Pulmonary zygomycosis--a rare angioinvasive fungal infection]

Zygomycosis caused by Rhizopus species is an aggressive and rapidly progressive opportunistic fungal infection in immunocompromised patients. It comprises mucocutaneous, rhinocerebral, pulmonary, urological and disseminated infections. Predisposing factors are immunosuppression owing to severe diseases, immunological defects or metabolic disturbances like diabetic ketoacidosis. Rhizopus infections are characterized by angioinvasive growth, necroses of infected tissue and perineural invasion. The histopathologic demonstrable invasion of blood vessels is remarkable for a fungal infection. The mortality of zygomycosis is very high, especially for disseminated disease and when immunosuppression cannot be corrected. We report about two cases of pulmonary zygomycosis, caused by Rhizopus spp.: patient 1, female 73 years old: Delayed clinical course according to hip arthroplasty infection and infection of a femoropopliteal bypass of the right leg, eventually exarticulation of the right hip joint, Pseudomonas pneumonia, severe sepsis caused by staphylococci, acute respiratory distress syndrome (ARDs), acute renal failure and multiple use of antibiotics. Subsequently detection of Rhizopus spp. in the bronchoalveolar lavage and treatment with amphotericin B for this reason. Patient 2, male 68 years old: transplantation of kidney in past medical history, presenting with acute renal failure and with quite a few infections before. In the sequel development of abscessing pneumonia on the right side with a pleural empyema. Rhizopus spp. were detected by microbiological testing in the empyema fluid. These findings required surgical intervention, resection of the lower lobe of the right lung and within the same operation of the renal graft because of rejection. The patient was treated with caspofungin. The further course was delayed by several septic phases. Both patients died later on in spite of all efforts. The very rarely seen pulmonary zygomycosis caused by infection with Rhizopus spp. developed in both patients owing to immunosuppression, in one patient iatrogenically induced by immunosuppressive drugs after organ transplantation, in the other as a result of prolonged severe sepsis. In comparison with other mycoses treatment of Rhizopus infections remains difficult. The affinity to blood vessels, where the fungi multiply, and their feature of vascular invasion with thrombosis and infarction complicate therapeutic efforts.

Prospective audit of bacteraemia management in a university hospital ICU using a general strategy of short-course monotherapy

OBJECTIVE

As optimal antibiotic therapy for bacteraemia remains unknown, different strategies have evolved. Routine practice in the University College London Hospitals intensive care unit (ICU) is to use short-course (5-6 days) monotherapy, unless specifically indicated (e.g. endocarditis, osteomyelitis). We decided to assess this approach for treating community-, hospital-, and ICU-acquired bacteraemia by monitoring clinical response, relapse rate and patient outcome.

DESIGN

Six-month prospective observational study from February to July 2000.

SETTING

Mixed medical-surgical tertiary referral ICU.

PATIENTS

All 713 patients admitted to the ICU over the study period.

MEASUREMENTS AND RESULTS

In total, 102 bacteraemic episodes occurred in 84 patients. Eight (57%) of 14 community-acquired bacteraemias, 22 (79%) of 28 hospital-acquired bacteraemias, and 48 (80%) of 60 ICU-acquired bacteraemias (in 49 patients) were treated with short-course monotherapy. Compared with previous reported studies, these patients had a low rate (23.8%) of death directly attributable to the bacteraemia and a satisfactory clinical response in 72%. Of six relapses (all Gram-negative), four had received combination therapy for severe deep-seated infections. ICU-acquired multidrug-resistant Gram-negative bacteraemias (6.5%) and fungaemias (3%) were also uncommon. No patient discharged from ICU subsequently developed a new bacteraemia relapse, or any long-term complication such as osteomyelitis.

CONCLUSIONS

Our general strategy of short-course antibiotic monotherapy for treating bacteraemia in the critically ill appears to provide a satisfactory clinical response, low relapse rate and no long-term complications in a well-defined group of patients. Multicentre studies are warranted to compare short versus long course therapy, and monotherapy versus combination therapy.

Potential risk factors for infection with Candida spp. in critically ill patients

The incidence, risk factors and prognostic factors for candidal infection were determined in a prospective study of 280 infected patients. Thirty-one (11%) patients were infected with Candida spp., sub-divided into 18 (58%) with C. albicans, and 13 (42%) with non-albicans spp. (six C. glabrata, three C. parapsilosis, and one each of C. krusei, C. tropicalis, C. guilliermondii and C. lusitaniae). Infection with Candida spp. was always associated with concurrent bacterial infection. By univariate logistic regression analysis, the degree of morbidity and the duration of mechanical ventilation were independent predictive factors for death, but infection with Candida spp., was not. Factors associated with Candida spp. infection were the degree of morbidity, intensive care unit length of stay, alterations of immune response, and the number of medical devices involved. By multivariate logistic regression analysis, the only independent risk factor for candidal infection was intensive care unit length of stay.

Invasive aspergillosis in critically ill patients: attributable mortality and excesses in length of ICU stay and ventilator dependence

Invasive aspergillosis is a rare disease in intensive care unit (ICU) patients and carries a poor prognosis. The aim of the present study was to determine the attributable mortality due to invasive aspergillosis in critically ill patients. In a retrospective, matched cohort study (July 1997-December 1999), 37 ICU patients with invasive aspergillosis were identified together with 74 control patients. Matching of control (1:2) patients was based on the acute physiology and chronic health evaluation (APACHE) II classification: an equal APACHE II score (+/-1 point) and diagnostic category. This matching procedure results in an equal expected in-hospital mortality for cases and controls. Additionally, control patients were required to have an ICU stay equivalent to or longer than the case before the first culture positive for Aspergillus spp. Patients with invasive aspergillosis were more likely to experience acute renal failure (43.2% versus 20.5%; P = 0.020). They also had a longer ICU stay (median: 13 days versus seven days; P < 0.001) as well as a more extended period of mechanical ventilator dependency (median: 13 days versus four days; P < 0.001). Hospital mortalities for cases and controls were 75.7% versus 56.8%, respectively (P=0.051). The attributable mortality was 18.9% (95% CI: 1.1-36.7). A multivariate survival analysis showed invasive aspergillosis [hazard ratio (HR): 1.9, 95% CI: 1.2-3.0; P = 0.004] and acute respiratory failure (HR: 6.5, 95%: 1.4-29.3; P < 0.016) to be independently associated with in-hospital mortality. In conclusion, it was found that invasive aspergillosis in ICU patients carries a significant attributable mortality of 18.9%. In a multivariate analysis, adjusting for other co-morbidity factors, invasive aspergillosis was recognized as an independent predictor of mortality.

Fungal infections in patients with severe acute pancreatitis and the use of prophylactic therapy

Data from an 8-year period for 46 patients with severe acute pancreatitis and infected pancreatic necrosis were analyzed to determine the incidence of fungal infection, to identify risk factors for the development of fungal infection, and to assess the use of early fluconazole treatment. Intraabdominal fungal infection was found in 17 (37%) of 46 patients. Candida albicans was isolated most frequently (15 patients); Candida tropicalis and Candida krusei were found in 1 patient each. Characteristics of patients with fungal infection were not different from patients without fungal infection. The difference in mortality was not statistically significant between patients with fungal infection and patients without fungal infection. Early antifungal therapy (prophylactic or preemptive antifungal therapy) was administered to 18 patients, and only 3 of them developed fungal infection. In this cohort of critically ill patients, no risk factors for fungal infection could be demonstrated, and mortality among patients who received early antifungal therapy was not different. Early treatment with fluconazole seems to prevent fungal infection in these high-risk patients.

Fluconazole: optimized antifungal therapy based on pharmacokinetics

Fluconazole, a triazole, inhibits synthesis of ergosterol. The key enzyme of antifungal activity is C-14-Demethylase, which itself depends on Cytochrom-P-450. So drugs that inhibit or induce this enzyme lead to interactions that have to be considered when dosing fluconazole. Oral bioavailability is more than 90% after a 50 mg dose, peak levels are reached after 0.5-1.5 h (empty stomach) or 4 h (with nutrition). A loading dose on the first day leads to steady state levels on the second day. Because of the hydrophilic properties fluconazole penetrates very well into body fluids and tissues. With the M27 method conditions regarding susceptibility testing have been standardized and minimal inhibitory concentrations (MICs) have been established for fluconazole. The linear relation between dose and concentration offers the possibility to treat less susceptible fungi with higher doses, but only when MICs correlate with efficacy and higher doses are tolerated as well. Prospectively randomized studies are rare. With the limited data indications as consensus recommendations are demonstrated. Data regarding high dose therapy with fluconazole in surgical or intensive care patients demonstrate efficacy and tolerability. In addition dosage has to be adjusted in case of haemofiltration or haemodialysis. At last future options for high dose fluconazole are discussed.

[Candida pneumonia in patients without definitive immunodeficiency]

The occurrence of community-acquired pneumonia due to yeast-like fungi of the genus Candida in patients without manifest immunodeficiency has previously been discounted. However, such pneumonias may indeed occur in patients with chronic parenchymal lung damage, e.g. from nicotine. Candida pneumonia can be triggered in these patients for example by trivial viral infections. Three corresponding cases are discussed.

[Invasive candidosis in intensive care unit patients]

The incidence of invasive candidosis is increasing worldwide and the mortality is high. In the intensive care unit diagnostic measurements, correct evaluation of the findings and the right indication for antifungal treatment remain problematic. So determination of potential risk factors is very important. The therapeutic use of antifungal drugs is often limited by important disadvantages like inadequate spectrum, application form or side effects. New antifungals give hope for the near future.

Immunoglobulins G could prevent adherence of Candida albicans to polystyrene and extracellular matrix components

Immunocompromised patients are at high risk of developing Candida infections. Although cell-mediated immunity is generally believed to play the main role in defence against fungi, antibodies could also be effective in immune defence by different mechanisms of action. The adherence capacity of four strains of Candida albicans to polystyrene and to some extracellular matrix components was investigated after incubation of the yeasts with non-specific and specific anti-C. albicans IgG. Experiments were carried out using a colorimetric method based upon the reduction of XTT tetrazolium (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) by mitochondrially active blastospores in the presence of menadione. Incubation of the yeasts with IgG, specific or not, caused a decrease in the capacity for adherence to the surfaces studied. There was no significant effect of the specificity of the tested antibodies on the reduction of adherence capacity. In conclusion, total IgG could play a role in blocking the binding of C. albicans to host and medical device surfaces. These results suggest that regular survey of levels of total IgG in patients suffering from severe hypogammaglobulinaemia could be of interest for the prevention of systemic candidiasis.

Effects of nosocomial candidemia on outcomes of critically ill patients

PURPOSE

To determine whether nosocomial candidemia is associated with increased mortality in intensive care unit (ICU) patients.

SUBJECTS AND METHODS

We performed a retrospective (1992 to 2000) cohort study of 73 ICU patients with candidemia and 146 matched controls. Controls were matched based on disease severity as measured by the Acute Physiology and Chronic Health Evaluation (APACHE) II score (+/- 1 point), diagnostic category, and length of ICU stay before onset of candidemia.

RESULTS

In comparison with the control group, patients with candidemia developed more acute respiratory failure (97% [n = 71] vs. 88% [n = 129], P = 0.03) during their ICU stay. They were mechanically ventilated for a longer period (29 +/- 26 days vs. 19 +/- 19 days, P<0.01) and had a longer stay in the ICU (36 +/- 33 days vs. 25 +/- 23 days, P = 0.02) as well as in the hospital (77 +/- 81 days vs. 64 +/- 69 days, P = 0.04). There was no difference in in-hospital mortality between the groups (48% [n = 35] vs. 43% [n = 62], P = 0.44), a difference of 5% (95% confidence interval [CI]: -8% to 19%). In a multivariate analysis, older age (hazard ratio [HR] = 1.13 per 10 years; 95% CI: 1.04 to 1.23; P = 0.004), acute renal failure (HR = 1.4; 95% CI: 1.1 to 2.0; P = 0.02), and unfavorable APACHE II scores (HR = 1.10 per 5 points; 95% CI: 1.00 to 1.20; P = 0.05) were independent predictors of mortality. Candidemia was not associated with mortality in a model that adjusted for these factors (HR = 0.9; 95% CI: 0.7 to 1.2; P = 0.53).

CONCLUSION

Nosocomial candidemia does not adversely affect the outcome in ICU patients in whom mortality is attributable to age, the severity of underlying disease, and acute illness.

A quantitative study of the survival of two species of Candida on porous and non-porous environmental surfaces and hands

AIMS

In spite of the importance of many species of Candida as human pathogens, little is known about their ability to survive on animate and inanimate surfaces. Such information is essential in understanding the vehicles and modes of their spread, and in designing proper infection control strategies against them. The aim of this study was to generate comparative quantitative data in this regard.

METHODS AND RESULTS

The survival of one clinical isolate each of Candida albicans and C. parapsilosis on two types of hard inanimate surfaces (glass and stainless steel) and two types of fabrics (100% cotton and a blend of 50% cotton and 50% polyester) was evaluated under ambient conditions (air temperature 22 +/- 2 degrees C; relative humidity 45-62%) using quantitative test protocols. The survival of C. albicans was also assessed on human skin, using the fingerpads of adult volunteers as carriers. Each carrier surface received 10 microl of the test suspension containing a soil load to simulate body fluids. When dried on glass and stainless steel carriers, C. albicans and C. parapsilosis remained viable for at least three and 14 days, respectively. Both species could survive for at least 14 days on both types of fabric. On the skin, 20% of the viable C. albicans remained detectable one hour post-inoculation.

SIGNIFICANCE AND IMPACT OF THE STUDY

This quantitative and comparative study demonstrated the potential for, and differences in the ability of clinically significant species of Candida to remain viable on porous and non-porous inanimate surfaces as well as on human hands. These results should help in understanding the epidemiology of nosocomial infections due to Candida, and in designing better prevention and control strategies against them.

Significance of Candida recovered from intraoperative specimens in patients with intra-abdominal perforations

OBJECTIVE

Determine the significance of recovering yeasts from intraoperative specimens from the abdominal cavity and to evaluate the effect of a single intraoperative dose of fluconazole on clinical outcome in patients with intra-abdominal perforations.

DESIGN

Prospective, randomized, double-blind study.

SETTING

Multicenter study from 13 hospitals in Norway.

PATIENTS

One hundred nine patients with intra-abdominal perforations.

INTERVENTIONS

Patients were randomized to receive either a single 400-mg fluconazole dose or placebo during the operation.

MEASUREMENTS AND MAIN RESULTS

An intra-abdominal specimen for microbiological culture was obtained at the time of the operation. The primary response variable in the study was death. Secondary response variables were three parameters indicating a complicated postoperative period: mechanical ventilation for > or = 5 days, intensive care treatment for > or = 10 days, and use of a central venous catheter for > or = 10 days. Yeasts were recovered from a intraoperative intra-abdominal specimen from only 1 (3.5%) of 28 patients with perforated appendicitis and from 32 (39.5%) of 81 nonappendicitis patients. Excluding the appendicitis patients, the yeast recovery rate was high both for patients hospitalized at the time of the perforation (45%) and for nonhospitalized patients (32%). The overall mortality was 11% (12 patients). Single-dose intraoperative fluconazole prophylaxis did not reach a statistically significant effect on mortality (4 of 53 patients in the fluconazole group and 8 of 56 patients in the placebo group died [p = .059]). The only two explanatory variables significantly related to death were a intraoperative finding of yeast from an intra-abdominal specimen and the occurrence of a spontaneous perforation in a patient already hospitalized for nonsurgical cancer treatment. Detection of yeast was also a significant explanatory variable for a prolonged period of mechanical ventilation, intensive care treatment, and prolonged use of a central venous catheter.

CONCLUSIONS

Single-dose intraoperative fluconazole prophylaxis did not have a statistically significant effect on overall mortality (odds ratio = 0.21; 95% confidence interval, 0.04-1.06; p = .059) in patients with intra-abdominal perforation. The recovery rate of yeast from intraoperative specimens from the abdominal cavity was high (>30%) and was associated with death and a complicated postoperative course.

Diagnosis of systemic Candida infections in patients of the intensive care unit. Significance of serum antigens and antibodies

The combined detection of Candida antigen and antibody for the determination of systemic Candida infections (SCI) was investigated. One hundred and four patients from the intensive care unit (ICU) were analysed. Seventeen of the patients were suspected of having SCI, based on clinical and laboratory criteria. In these patients, Candida antigens and antibodies were analysed extensively. Ten patients had a positive Candida antigen (titre >1:16) determined by the latex agglutination assay Cand-Tec(R) and their median antibody titre was 1:160 in the indirect haemagglutination test (HAT). Seven antigen-negative patients had a median titre of 1:1280 (HAT). Forty-one of 42 colonized control patients had negative antigen titres and a median antibody titre of 1:160. The sensitivities and specificities were 58.8% and 97.6% for antigenemia, and 52.9% and 85.7% for antibody detection. These values reached 100.0% and 83.3%, respectively, when the results of both tests were combined. This indicates a high degree of concordance between serological results (Candida antigen and/or antibodies) and clinical presentation. We conclude, that the combined investigation of antigen and antibody titres might be a helpful tool in the characterization of SCI in ICU patients, if antigen titres are >or=1:16 or antibody titres (HAT) are >or=1:640.

Testing chemical germicides against Candida species using quantitative carrier and fingerpad methods

Six disinfectants were tested against Candida albicans, C. parapsilosis and C. tropicalis using quantitative carrier tests based on glass (QCT-1) and metal (QCT-2) surfaces. C. albicans was also used to test four topical agents by a fingerpad method. Hard water (200 ppm as CaCO(3)) was the product diluent. In preliminary tests with QCT-1 and QCT-2, the testing was with or without a soil load; subsequent tests and fingerpad tests included soil. In QCT-1 and QCT-2, each carrier received 10 microL (5.0 x 10(6) - 1.0 x 10(7)colony forming units) of Candida, and was air dried for 1 h, then exposed to 1 mL or 50 microL of test product at 22 +/- 2 degrees C for up to 10 min. Controls received an equivalent volume of saline. For fingerpad tests, each digit received 10 microL of inoculum, which was allowed to dry and exposed to 1 mL of test product for 20 s. Inoculated plates of Sabouraud's dextrose agar were held for 48 h at 30 degrees C and colonies counted to determine reductions in colony forming units. In tests on both hard surfaces and fingerpads, ethanol and products based on ethanol reliably and rapidly inactivated all the Candida species tested. Products with sufficient potency to have tuberculocidal claims produced substantial reductions in the titre of C. albicans, although some showed a lesser reduction in titre of C. tropicalis and C. parapsilosis. This may reflect differences in cell hydrophobicity between Candida species, and highlights the need for care in selecting a suitable surrogate for disinfectant tests. The quantitative carrier and fingerpad protocols are suitable for assessing the activity of disinfectants and topical antiseptics against candida.

Rate of transmission and endogenous origin of Candida albicans and Candida glabrata on adult intensive care units studied by pulsed field gel electrophoresis

We determined the relative roles of endogenous origin and patient-to-patient transmission in Candida colonization of patients on adult intensive care units (ICU). A total of 48 Candida albicans and 18 Candida glabrata strains from various clinical samples of 28 long-term patients, hospitalized in two neurological ICUs between April and June 1999, were typed using pulsed field gel electrophoresis (PFGE). Three patients were co-colonized by both C. albicans and C. glabrata strains. Twenty-four C. albicans and 17 C. glabrata karyotypes were defined. The colonization was found to be polyclonal in six C. albicans and five C. glabrata patients. Twenty-six patients (93%) carried strains, which were not detected in other patients hospitalized at the same time, i.e. they were colonized by unique C. albicans and C. glabrata strains. Only two patients, who were hospitalized during the same period of time, although in different rooms of the same ICU, shared strains with an identical PFGE type, indicating possible patient-to-patient transmission. Patient-to-patient transmission of yeasts played a minor role on these ICUs.

Approaches to antifungal therapy in the intensive care unit

The risk of fungal infection is increasing in intensive care unit patients and the spectrum of pathogens is changing. A number of new antifungal agents are becoming available, but their use in critically ill patients has not been assessed in randomized controlled trials. Furthermore, distinguishing colonization from infection is problematic in intensive care unit patients. Clinicians who are involved in the management of intensive care unit patients must remain vigilant and devise a risk-based antifungal strategy that is based on local experience and susceptibility patterns.

Fungi, mycological disease and pathogenic determinants

The rapid evolution of human fungal infections is providing a strong impetus for understanding pathogenesis and host-fungus interactions and hence new diagnostics.

Epidemiology

Invasive fungal infections have emerged as important causes of hospital related morbidity and mortality. They are increasingly seen in patients not previously considered at risk, e.g. patients on an intensive care unit. Candida albicans and Aspergillus spp. are the most common pathogens, posing challenges in epidemiology, control and treatment.

Intensive care unit design and environmental factors in the acquisition of infection

The incidence of infection in the intensive care unit (ICU) is one of the highest in the hospital and yet facilities to prevent infection are often inadequate in this important clinical area. Many antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), Serratia marcescens and vancomycin-resistant enterococci (VRE), may survive and persist in the environment leading to recurrent outbreaks. A number of professional and scientific bodies in the UK, the USA and Europe have published guidelines on the design and layout of ICUs. All emphasize the importance of adequate isolation facilities (at least one cubicle for every six beds), sufficient space around each bed (20 m2), wash hand basins between every other bed, ventilation including positive and negative pressure ventilation for high risk patients and sufficient storage and utility space. Common sense and considerations of safety and comfort should guide decisions on floors, walls etc. Appropriate cleaning and disinfection programmes are essential to render the ICU relatively pathogen free and compliance with handwashing is imperative in minimizing infection in this high-risk area. Infection control teams should support ICU personnel in their efforts to upgrade facilities and help ensure that this is a priority when resources are limited.

High level of recovery of fungi from water and dialysate in haemodialysis units

The counts of yeasts and filamentous fungi were investigated in the municipal water supplies of haemodialysis centres, in the treated water and the dialysate from all 85 haemodialysis units in Greece, in order to estimate their occurrence, their correlation with contamination indicator bacteria and other influencing factors. Filamentous fungi and yeasts were isolated from 69 (81.2%) and from three (3.5%) feed water samples, from 74 (87.1%) and seven (8.2%) treated water samples and from 66 (77.7%) and 11 (12.9%) dialysate samples respectively. Aspergillus spp and Penicillium spp were the most frequent moulds, while Candida spp were the prevailing yeasts. The occurrence of yeasts was significantly higher in dialysate than in tap water samples. Counts of filamentous fungi in all 255 samples were significantly correlated with the counts of total heterotrophic bacteria and enterococci, whereas the counts of yeasts were correlated with faecal coliforms, total heterotrophic bacteria, as well as enterococci, Pseudomonas spp and total coliforms, while no correlation was detected with the age of either haemodialysis units, the age of water treatment system, the number of artificial kidney machines or the components of the water purification system. High recovery of fungi from haemodialysis aqueous environments implies a potential risk for haemodialysis patients and indicates the need for continuous maintenance and monitoring.