A randomized trial comparing fluconazole with amphotericin B for the treatment of candidemia in patients without neutropenia. Candidemia Study Group and the National Institute

Hazards of inadequate fluconazole dosage to treat deep-seated or systemic Candida albicans infection

We report three cases of deep-seated and systemic Candida albicans infection in which inadequate dosages of fluconazole were used, leading to breakthrough fungaemia, candidal osteomyelitis and endocarditis. The need to modify fluconazole dosage in patients receiving continuous venovenous haemofiltration is discussed.

How to use an article on therapy or prevention: pneumonia prevention using subglottic secretion drainage

Evidence based critical care medicine involves integrating clinical experience, expertise, and patient preferences with explicit, systematic, and judicious use of current best evidence in making medical decisions. Published evidence has many sources: research from the basic sciences of medicine, and from patient-centered clinical research on the accuracy of diagnostic tests, the power of prognostic markers, and the effectiveness and safety of preventive, therapeutic, rehabilitative, and palliative interventions. When critically appraising a clinical article for potential use in intensive care unit (ICU) practice, the first question we ask ourselves is: Is this study valid? If examination of the study methods reveals that the design is rigorous, we can turn to the two other key questions: What are the results? and, Will the results help me care for my patients? This approach may aid in the interpretation of an article on therapy or prevention; in it we discuss a strategy designed to prevent ventilator associated pneumonia in critically ill patients.

Comparison of the in vitro activities of the echinocandin LY303366, the pneumocandin MK-0991, and fluconazole against Candida species and Cryptococcus neoformans

Two new glucan synthesis inhibitors, the echinocandin LY303366 and the pneumocandin MK-0991 (formerly L-743,872), were studied for their antifungal activities in vitro in relation to each other and in relation to the activity of the triazole fluconazole. Systematic analysis of broth macrodilution testing by varying the starting inoculum size, medium composition, medium pH, temperature of incubation, length of incubation, or selection of endpoints failed to identify significant differences in antifungal activity for either LY303366 or MK-0991 in comparison to the activity under standard test conditions specified for other antifungal agents in National Committee for Clinical Laboratory Standards (NCCLS) document M27A. Under standardized conditions, both drugs exhibited prominent activity against Candida species including Candida glabrata and Candida krusei but showed little activity against Cryptococcus neoformans. This spectrum of activity differed from that of fluconazole, which exhibited marginal activity against C. glabrata and C. krusei but prominent activity against other Candida species and C. neoformans. For individual strains, broth microdilution MICs of LY303366 and MK-0991 were similar to but frequently higher than broth macrodilution results. In contrast, fluconazole broth microdilution MICs were often lower than broth microdilution results. We conclude that the test conditions specified in NCCLS document M27A are applicable to these two new glucan synthesis inhibitors and that systematic differences between broth microdilution procedures and the broth macrodilution reference standard will need to be addressed before the two test methods can be used interchangeably.

Treatment of murine Candida krusei or Candida glabrata infection with L-743,872

L-743,872 is a broad-spectrum pneumocandin antifungal drug developed by Merck Research Co., and in the present work it was evaluated in vivo in murine models of Candida krusei and Candida glabrata infection. Mice were infected intravenously with two isolates of C. krusei and treated with fluconazole or L-743,872. Fluconazole was beneficial only in immune-competent mice infected with isolate 94-2696. At > 0.5 mg/kg of body weight/day, L-743,872 was effective against both infecting isolates in immune-competent and immune-suppressed mice. Against C. glabrata, L-743,872 was effective, at doses > or = 0.5 mg/kg, in reducing fungal cell counts in the kidneys but not in the spleen. L-743,872 has significant potential for clinical development.

Treatment of murine disseminated candidiasis with L-743,872

L-743,872 (M991), which is a pneumocandin derivative, was evaluated in a mouse model of disseminated candidiasis caused by a fluconazole-resistant isolate of Candida albicans. In immunocompetent mice M991 prolonged survival at doses as low as 0.0125 mg/kg of body weight per day. In neutropenic mice 0.05 mg/kg was the lowest effective dose. M991 is a very potent drug for treatment of disseminated candidiasis.

Mixed Candida glabrata and Candida albicans disseminated candidiasis in a heroin addict

The case of a white-heroin addict who developed disseminated candidiasis following coinfection by Candida glabrata and Candida albicans is reported. Genomic random amplified polymorphic DNA typing suggested that the Candida glabrata blood isolates originated in the oral cavity of the patient. This case strengthens the evidence that Candida species other than Candida albicans can be involved in the pathogenesis of disseminated candidiasis in heroin addicts.

Toxicity and efficacy of conventional amphotericin B deoxycholate versus escalating doses of amphotericin B deoxycholate---fat emulsion in HIV-infected patients with oral candidosis

BACKGROUND: Amphotericin B deoxycholate remains the treatment of choice for most systemic fungal infections; however, its clinical use can be limited by infusion-related side effects and nephrotoxicity. New formulations of amphotericin in lipid compounds have been shown to decrease toxicity. We previously showed that a lipid emulsion preparation of amphotericin B deoxycholate was better tolerated than the conventional preparation in dextrose. Therefore, we have now studied the clinical tolerance, renal toxicity and efficacy of higher doses of amphotericin B deoxycholate prepared and infused in a fat emulsion (Intralipid 20%). Thus, this report adds information to the previous publication. METHODS: Forty-two patients infected with HIV and suffering oral candidosis entered the study. The patients received either amphotericin B deoxycholate---glucose 1 mg/kg/day or amphotericin B deoxycholate---lipid emulsion 1 mg/kg/day for 4 days (randomized phase), or amphotericin B deoxycholate---lipid emulsion 2 mg/kg/day or 3 mg/kg/day (escalating-dose phase) for 5 days. Clinical (immediate) side effects and renal (creatinine) tolerance were assessed daily; efficacy against oral candidosis was measured by using a simple clinical score. Serum levels of amphotericin B were also measured. RESULTS: None of the patients receiving amphotericin B deoxycholate---lipid emulsion had treatment interrupted, as compared to four (36%) in the amphotericin B deoxycholate---glucose group (pless-than-or-equal0.01); chills during or after the infusions were significantly less frequent in the amphotericin B deoxycholate---lipid emulsion groups than in the amphotericin B deoxycholate-glucose group (p=0.03). The increase of creatininemia during treatment was significantly higher for patients receiving amphotericin B deoxycholate---glucose than for those receiving amphotericin B deoxycholate---lipid emulsion (p=0.001). The number of patients who had a creatininemia greater-than-or-equal18 mg/L during treatment was significantly higher in both the amphotericin B deoxycholate---glucose group (36%) and in the group receiving the highest dose of amphotericin B deoxycholate---lipid emulsion than in other groups (pless-than-or-equal0.06). The serum concentrations of amphotericin B were lower for the amphotericin B deoxycholate---lipid emulsion regimen than for the amphotericin B deoxycholate---glucose regimen at the same dose of 1 mg/kg/day, but increased with the dose. The change of the oral candidosis score was similar for the same dose of 1 mg/kg/day of amphotericin B deoxycholate infused in either glucose or lipid emulsion; higher doses of amphotericin B deoxycholate---lipid emulsion were more efficacious (p=0.009) and this efficacy seemed to increase with the dose (p=0.06). CONCLUSIONS: The clinical and renal tolerance of amphotericin B deoxycholate are improved when the drug is directly prepared and infused in lipid emulsion (Intrapid) and this preparation allows for greater dosage, up to 3 mg/kg/day, with resultant greater efficacy. This preparation is simple and cost-effective (approximately 7 US $ per 50 mg of amphotercin B) and could be clinically compared to other formulations of amphotericin B.

The search for new triazole antifungal agents

The first generation antifungal agent triazoles, fluconazole and itraconazole, have revolutionised the treatment of serious fungal infections such as mucosal and invasive candidiasis and cryptococcal meningitis. However, the treatment of some fungal infections, particularly aspergillosis, is still far from satisfactory and thus there is an important requirement for new broad-spectrum antifungal agents. The new second generation triazoles voriconazole and SCH-56592 show considerable promise in achieving this goal in the near future.

Sequential treatment of deep fungal infections with amphotericin B deoxycholate and amphotericin B colloidal dispersion

Amphotericin B colloidal dispersion (ABCD) is a novel lipid formulation of amphotericin B designed to diminish toxic effects of the drug. In the following report, nine cases of suspected (n = 4) and proven (n = 5) deep Candida infection, treated sequentially with amphotericin B deoxycholate and ABCD, are presented. The treatment was successful in seven cases. During treatment with amphotericin B deoxycholate, a rise in serum creatinine was observed in seven patients, hypokalemia in five, and metabolic acidosis in four. After replacing amphotericin B deoxycholate with ABCD, laboratory parameters improved in four of the seven patients with increased creatinine, in four of the five patients with hypokalemia, and in two of the four patients with metabolic acidosis. Infusion-related rigors were observed in four patients receiving amphotericin B deoxycholate and in one patient treated with ABCD. Reversible elevation of liver enzymes was found in one patient receiving ABCD. In this study ABCD proved less toxic than amphotericin B deoxycholate. The efficacy of ABCD alone cannot be assessed because of previous treatment with amphotericin B deoxycholate, but sequential treatment of deep Candida infections with amphotericin B deoxycholate and ABCD seems to be an effective therapeutic modality, especially in patients requiring prolonged administration of amphotericin B.

Antifungal prophylaxis during neutropenia and immunodeficiency

Fungal infections represent a major source of morbidity and mortality in patients with almost all types of immunodeficiencies. These infections may be nosocomial (aspergillosis) or community acquired (cryptococcosis), or both (candidiasis). Endemic mycoses such as histoplasmosis, coccidioidomycosis, and penicilliosis may infect many immunocompromised hosts in some geographic areas and thereby create major public health problems. With the wide availability of oral azoles, antifungal prophylactic strategies have been extensively developed. However, only a few well-designed studies involving strict criteria have been performed, mostly in patients with hematological malignancies or AIDS. In these situations, the best dose and duration of administration of the antifungal drug often remain to be determined. In high-risk neutropenic or bone marrow transplant patients, fluconazole is effective for the prevention of superficial and/or systemic candidal infections but is not always able to prolong overall survival and potentially selects less susceptible or resistant Candida spp. Primary prophylaxis against aspergillosis remains investigative. At present, no standard general recommendation for primary antifungal prophylaxis can be proposed for AIDS patients or transplant recipients. However, for persistently immunocompromised patients who previously experienced a noncandidal systemic fungal infection, prolonged suppressive antifungal therapy is often indicated to prevent a relapse. Better strategies for controlling immune deficiencies should also help to avoid some potentially life-threatening deep mycoses. When prescribing antifungal prophylaxis, physicians should be aware of the potential emergence of resistant strains, drug-drug interactions, and the cost. Well-designed, randomized, multicenter clinical trials in high-risk immunocompromised hosts are urgently needed to better define how to prevent severe invasive mycoses.

Nosocomial Candida. Epidemiology, transmission, and prevention

The NNIS and the newly established SCOPE data indicate that the relative proportion of organisms causing nosocomial bloodstream infections has changed over the last decade, with Candida species now being firmly established as one of the most frequent agents. The epidemiology of nosocomial candidemia is continually being refined, but established predisposing factors including immunosuppression and malignancies, use of broad spectrum antibiotics, and use of indwelling central catheters remain as significant risk factors. The high cost of health care and greater attention to continuous quality improvement will stimulate better and more effective ways of diagnosing and treating candida infections using combined clinical and microbiologic acumen. There is room for optimism as newer antifungal agents with reduced toxicities have impact on therapy of candidal infections. Aggressive development of still more agents and reformulations of older agents continue in earnest. Even greater consolation comes from the increased awareness of lay and medical personnel alike regarding the appropriate and judicious use of antimicrobial agents.

In vitro activity of a new echinocandin, LY303366, compared with those of amphotericin B and fluconazole against clinical yeast isolates

The in vitro activity of LY303366, a new echinocandin derivative, was evaluated with 191 yeast isolates by a broth microdilution method. The MICs at which 50% of the isolates were inhibited were 0.125 microg/ml for Candida albicans and C. tropicalis, 0.25 microg/ml for C. krusei, C. kefyr, and C. glabrata, and 2.0 microg/ml for C. parapsilosis.

Reduction in the nephrotoxicity of amphotericin B when administered in 20% intralipid

The administration of amphotericin B (AmB) is often limited by the development of nephrotoxicity. In a pilot crossover trial, aqueous AmB followed by a new preparation of a mixture of AmB with 20% intralipid (AmB-IL) was administered to 10 immunocompromised patients for systemic fungal infections caused by Candida species. Mean total dose and duration of therapy with AmB-IL exceeded that of aqueous AmB (649±165 mg versus 394±105 mg, P=0.061 and 13.2±2.5 days versus 9±2.1 days, P=0.31). However, mean creatinine clearance of the patients rose during AmB-IL therapy by 10.7±7.7 mL/min (P=0.03). AmB-IL warrants further investigation to assess its stability and efficacy for treating serious fungal infections.

Fluconazole concentrations in pulmonary tissue and pericardial fluid

In order to investigate the clinical efficacy of the triazole antifungal agent fluconazole (FCA) in the treatment of pulmonary mycosis, in the present study the concentrations of fluconazole in human pulmonary tissue, pericardial fluid and serum were determined at 1, 2, 12 and 13 h after intravenous administration of fluconazole 200 mg. The mean FCA concentrations in the serum were 4.04 mg/l (1 h), 3.82 mg/l (2 h), 2.35 mg/l (12 h) and 2.13 mg/l (13 h). The respective FCA levels in the pulmonary tissue were 4.64 mg/kg, 4.54 mg/kg; 3.50 mg/kg and 3.40 mg/kg and the concentrations in the pericardial fluid were 3.86 mg/l, 3.57 mg/l, 2.35 mg/l and 2.13 mg/l. The FCA concentrations in the pulmonary tissue that were statistically significant higher than the serum concentrations were found at 2 h, 12 h and 13 h after intravenous administration (p < 0.05).

Multicenter randomized trial of fluconazole versus amphotericin B for treatment of candidemia in non-neutropenic patients. Canadian Candidemia Study Group

A randomized trial was conducted to compare the efficacy and safety of fluconazole versus that of amphotericin B in the treatment of candidemia in non-neutropenic adults. Enrollment was stratified by disease severity (APACHE II score). Patients were randomized (1:1) to receive amphotericin B 0.6 mg/kg/day (cumulative dose 8 mg/kg) or fluconazole 800 mg intravenous loading dose, then 400 mg daily for four weeks (intravenous for at least 10 days). Patients were monitored for six months. A total of 106 patients were enrolled. A protocol amendment implemented midway through the trial required patients to be removed from the study and treated with amphotericin B if species identification indicated candidemia due to Candida glabrata or Candida krusei. Baseline characteristics were similar for the two groups; 103 patients (fluconazole, 50; amphotericin B, 53) met the major enrollment criteria. The intention-to-treat analysis indicated successful therapy in 50% of fluconazole recipients compared to 58% of the amphotericin B group (p = 0.39; one-sided 95% CI, -8 to 24%). The efficacy analysis included 84 patients (fluconazole, 42; amphotericin B, 42); successful outcomes were observed in 57% and 62% of cases in the fluconazole and amphotericin B groups, respectively (p = 0.66: one-sided 95% CI, -12 to 22%). The mortality at day 14 for the fluconazole group was 26% and for the amphotericin B group 21% (p = 0.52; chi-square test) and remained similar throughout the course of follow-up, Drug-related adverse events were more frequent with amphotericin B than with fluconazole and prompted switching of therapy for two (4%) and zero cases, respectively. Fluconazole and amphotericin B were associated with similar clinical response rates and survival in the treatment of candidemia among non-neutropenic patients; however, drug-related adverse events were more frequent with amphotericin B.

Assessment of detection of Candida mannoproteinemia as a method to differentiate central venous catheter-related candidemia from invasive disease

The proper management of candidemic patients is controversial because of the difficulties of an early differentiation of central venous catheter (CVC)-related candidemia from deep-seated invasive Candida infection. In particular, more information on possible markers of invasive disease is needed. We performed a retrospective, pilot investigation to assess the diagnostic potential of a dot immunobinding assay for Candida mannoprotein antigen in serial serum samples from 31 candidemic patients in the setting of hematologic malignancy. Mannoproteinemia (antigenemia) was detected in 1 of 14 (7.1%) patients with transient or CVC-related candidemia and in 13 of 17 (76.5%) patients with non-CVC-related persistent candidemia. Of the 11 subjects of this latter group with documented tissue invasion, 10 (91%) were antigenemic. The patients belonging to the different categories did not significantly differ in the duration of candidemia, nor was there any significant difference among the different groups of subjects either in the number of serum samples examined or in their collection time during candidemia. The day of the first antigenemic sample during candidemia greatly varied among subjects with invasive infection, although on average mannoproteinemia was detectable by the first week of candidemia. In summary, our data demonstrate a correlation between mannoproteinemia and tissue invasion by Candida spp. in candidemic patients and suggest that mannoprotein detection by our method has a potential for the diagnosis of invasive candidiasis in these subjects.

Azole resistance in Candida

Resistance of Candida to azoles is an increasing problem. Susceptibility testing of Candida against fluconazole and ketoconazole is now feasible and desirable. Good correlation of resistance in vitro with clinical failure of fluconazole therapy has now been shown in mucosal candidiasis. The relationship, if any, between resistance and clinical failure in the context of invasive candidiasis is not clear at present and additional correlative work needs to be done. Monitoring of resistance trends in Candida is clearly important now.

Large-scale multicentre study of fluconazole in the treatment of hospitalised patients with fungal infections. Multicentre European Study Group

The purpose of this prospective, open-label, noncomparative, multicentre study was to evaluate the efficacy and safety of fluconazole in the treatment of hospitalised patients with mycoses. A total of 587 patients with diagnosed fungal infections were enrolled. Fluconazole was given orally or intravenously in a 200 or 400 mg loading dose, followed by 100 or 200 mg once daily. The most common candidal infections were fungemia, esophageal candidiasis, bronchopulmonary candidiasis, peritonitis, oropharyngeal candidiasis, urinary tract infection and deep wound infection. Meningitis was the most common cryptococcal infection. Of the 291 evaluable patients with candidiasis, 96% (70/73) of AIDS patients and 79% (171/218) of non-AIDS patients were clinically cured or improved. Of the 36 evaluable patients with cryptococcosis, 69% (20/29) of AIDS patients and 100% (7/7) of non-AIDS patients responded clinically. The overall mycological eradication rate was 85%; eradication was similar in patients with and without AIDS. Most adverse events during fluconazole therapy were mild to moderate in severity. This investigation confirms the results of previous studies demonstrating high response rates to fluconazole therapy in AIDS and non-AIDS patients with fungal infections. Even during long-term therapy treatment-limiting adverse events were uncommon with fluconazole.

Candida tropicalis arthritis in a patient with acute myeloid leukemia successfully treated with fluconazole: case report and review of the literature

The case of a 77-year-old woman with acute myeloid leukemia who developed Candida tropicalis septic arthritis of the knee after remission-inducing chemotherapy is reported. A literature review of C. tropicalis non-prosthetic arthritis is included. The isolate was susceptible to fluconazole (MIC 0.25 mg/l). She was treated with fluconazole (400 mg orally) and frequent relieving synovial aspirations. After 1 month of antifungal therapy the synovial fluid became culture negative. Fluconazole concentration in the synovial fluid and serum were 20 mg/l and 19.4 mg/l, respectively. The patient was treated for a total of 7 months and made a full recovery. This is the first report of the successful use of fluconazole in the treatment of septic arthritis due to C. tropicalis.

Lipopeptide inhibitors of fungal glucan synthase

The echinocandins and pneumocandins are lipopeptide antifungal agents that inhibit the synthesis of 1,3-beta-D-glucan, an essential cell wall homopolysaccharide found in many pathogenic fungi. Compounds with this fungal-specific target have several attractive features: lack of mechanism-based toxicity, potential for fungicidal activity and activity against strains with intrinsic or acquired resistance mechanisms for existing antimycotics. Semi-synthetic analogues of naturally occurring lipopeptides are currently in clinical trials with the aim of treating systemic candidiasis and aspergillosis. Thus a fuller understanding of the target enzyme and its inhibition by these compounds should be useful for epidemiological and other clinical studies. Although it has been long known that lipopeptides inhibit fungal glucan synthase activity both in cell extracts and in whole cells, the genetic and biochemical identification of the proteins involved has been accomplished only recently. We now know that in Saccharomyces cerevisiae, glucan synthase is a heteromeric enzyme complex comprising one large integral membrane protein (specified by either FKS1 or by FKS2) and one small subunit more loosely associated with the membrane (specified by RHO1). Additional components may also be involved. The heteromeric enzyme complex containing Fks1p constitutes the majority of the activity found in vegetatively growing cells in this organism. The FKS2 gene product is needed for sporulation. Lipopeptides affect the function of the Fksp component from either FKS gene. The current model for interaction and regulation of these components in S. cerevisiae and the application to Candida albicans and other pathogenic fungi are discussed in this review.

Lot-to-lot variability of antibiotic medium 3 used for testing susceptibility of Candida isolates to amphotericin B

We have previously shown that use of antibiotic medium 3 in the microdilution variant of the M27-T test method permits detection of amphotericin B-resistant Candida isolates. As this medium is not standardized and our initial work used only a single lot of antibiotic medium 3, we studied the lot-to-lot variability of three commercial lots of antibiotic medium 3 obtained from two sources. The MICs obtained with the new lots were lower than those of with the original lot, but the new lots still consistently separated putatively resistant and putatively susceptible isolates and this permits proposal of possible breakpoints for this assay system.

In vitro studies of activities of the antifungal triazoles SCH56592 and itraconazole against Candida albicans, Cryptococcus neoformans, and other pathogenic yeasts

We investigated the effects of various assay conditions on the activities of two antifungal drugs, SCH56592 and itraconazole, against seven species of fungi by the broth macrodilution testing procedure proposed by the National Committee for Clinical Laboratory Standards (NCCLS). For both drugs, which are insoluble in water, the concentration and type of solubilizing agent produced differences in drug activity. Starting inoculum size differences from 10(2) to 10(5) yeast cells per ml resulted in approximately a fourfold effect on the MIC of both drugs, but other significant differences were not observed with variations in synthetic medium composition, pH, buffering reagent, or incubation temperature. Under standardized conditions of reference method M27-T with 1% polyethylene glycol as the solubilizing agent, median MICs of SCH56592 and itraconazole of 60 and 125 mg/ml, respectively, were demonstrated for 110 strains (12 to 23 strains for each of seven species). Broth microdilution results were typically severalfold higher than broth macrodilution results. We conclude that the NCCLS standard reference method can be applied without modification to the testing of SCH56592 and itraconazole, but particular attention to solubilizing the agents is critical to obtaining consistent results.

Safety of amphotericin B colloidal dispersion

The safety of amphotericin B colloidal dispersion (ABCD) was tested in five open-label Phase I/II clinical trials in 572 selected patients who had a fungal infection secondary to a severe underlying disease. In 442 cases ABCD was administered after therapy with amphotericin B, which had been withdrawn in 192 of them because of toxicity. One hundred and forty patients had pre-existing nephrotoxicity. ABCD doses of up to 6 mg/kg/day resulted in no differences in serum creatinine levels, even in patients with pre-existing renal failure. ABCD therapy resulted in no difference in liver function as measured by SGOT, alkaline phosphatase and total bilirubin levels in serum. Apart from thrombocytopenia, there was no significant alteration in hematological or other biochemical parameters in the blood. Adverse events attributable to ABCD requiring discontinuation of therapy occurred in 70 patients (12.2%). The most frequent of these were infusion-related adverse events, which occurred in 5.4% of patients. As a consequence, the maximum tolerated dose was set at 7.5 mg/kg/day. These studies show clearly that ABCD can be administered safely to patients without the risk of renal toxicity, even when renal impairment has already developed following therapy with conventional amphotericin B deoxycholate.

Timing of treatment for nonneutropenic patients colonized with Candida

There has been a continuing evolution of the clinical spectrum of Candida infection in nonneutropenic patients. With better understanding of the predisposing factors for fungemia in critically ill patients, interest now centers on indications for early therapy, prior to the progression of colonization to fungemia. Recent prospective trials have identified persistence of Candida species in repetitive cultures of various sites as an essential if not necessary precursor for fungemia. Treatment for patients requiring prolonged intensive-care-unit residence and demonstrating colonization with Candida is suggested, based on the frequency with which such patients progress to fungemia. The efficacy of such treatment is undocumented, and clinical trials of various regimens of polyene or azole antifungals is needed.

Diagnosis and treatment of bacteremia and intravascular catheter infections

The past decade has witnessed an explosive rise in the rate of bacteremia and intravascular catheter infection. Although gram-negative organisms continue to account for up to one third of these infections, gram-positive organisms have become increasingly prevalent pathogens. Virulent antibiotic-resistant bacterial strains have emerged and present a formidable treatment challenge. Simultaneously, management of catheter infection has evolved. Although patients who develop fungemia, gram-negative bacteremia, or sepsis syndrome are best treated by catheter removal in addition to antimicrobial therapy, an increasing body of evidence suggests that many gram-positive bacterial catheter infections can be treated by use of antimicrobial agents without catheter removal. Advances in catheter design and immunotherapy for sepsis syndrome also hold promise. Despite these innovations, determining the initial need for catheter placement, adherence to meticulous sterile surgical technique during insertion, and subsequent fastidious catheter maintenance remain the mainstays of preventing these potentially disastrous infections.

Clinical and laboratory diagnosis of invasive candida infection in neutropenic patients

Cancer patients, especially those with acute leukaemia, represent a group that has the greatest risk for deep fungal infection. Almost no cases were seen before the advent of modern chemotherapy, and prior to the availability of antibacterial agents, less than 5% of patients with acute leukaemia died of fungal infection. These infections are now responsible for 40% or more of the deaths at some institutions. Candida species continues to be the most common fungal pathogen. Rapid and specific diagnosis of invasive candiosis enabling early effective therapy is therefore an important measure for reducing mortality in patients. Here the current status of clinical and laboratory diagnosis of invasive candida infection in neutropenic patients is discussed and recommendations made as to future development programmes.

Fungal pulmonary complications

With AIDS has come a new level of T-cell immunosuppression, beyond that previously seen. The impact of the HIV pandemic on the field of fungal infections includes a major increase in the number of serious fungal infections, an increase in the severity of those infections, and even some entirely new manifestations of fungal illness. In this article fungal pulmonary complications of AIDS are discussed. T-cell opportunists including Cryptococcus neoformans and the endemic mycoses are the most important pathogens. Phagocyte opportunists, including Aspergillus species and agents of mucormycosis, are less important.

Cross-resistance phenotypes of fluconazole-resistant Candida species: results with 655 clinical isolates with different methods

Candida species test results with two broth macrodilution antifungal susceptibility methods were compared using 655 clinical isolates, and the frequency of fluconazole resistance and phenotypes of azole cross resistance are detailed. A method with an 80% inhibition endpoint (as compared to clear tube endpoint) suggested greater fluconazole susceptibility to C. albicans but had a less pronounced effect on C. glabrata, and seemed to have a negligible influence on results with C. parapsilosis and C. tropicalis. The latter were grouped as susceptible and resistant (based on achievable blood levels), respectively, by both methods. Cross resistance was method dependent and more pronounced with itraconazole than ketoconazole. In vivo correlations are needed to validate the groupings proposed by any in vitro method.

A randomized study comparing fluconazole with amphotericin B/5-flucytosine for the treatment of systemic Candida infections in intensive care patients

In this prospective, randomized study fluconazole and amphotericin B/5-flucytosine were compared in the treatment of systemic candidiasis. Seventy-two non-neutropenic intensive care patients with systemic Candida infections were enrolled. Thirty-six patients were randomly assigned to receive fluconazole (400 mg on the first day then 200 mg) and 36 were randomized to amphotericin B/5-flucytosine (1.0-1.5 mg/kg body weight every other day and 3 x 2.5 g flucytosine/day) for 14 days following the diagnosis. There was no statistically significant difference in clinical outcome in regard to the treatment of pneumonia and sepsis: 18/28 of the patients were treated successfully with fluconazole and 17/27 with amphotericin B/5-flucytosine. For the treatment of peritonitis, however, amphotericin B/5-flucytosine was more effective than fluconazole (55% vs. 25%). Furthermore, amphotericin B/5-flucytosine was found to be superior to fluconazole with regard to pathogen eradication (86% vs. 50%). Fluconazole was associated with less toxicity than amphotericin B/5-flucytosine.

Candida albicans arthritis one year after successful treatment of fungemia in a healthy infant

Fungal arthritis in pediatric patients is rare and is most often associated with hematogenous spread to the affected joint. It is generally seen concomitant with, or shortly after, fungemia. We report a case of an immunocompetent patient in whom candidal arthritis developed 1 year after initial fungemia. The initial candidiasis was considered to be adequately treated with amphotericin B. The Candida isolates from the neonatal fungemia and subsequent arthritis were the some as identified by electrophoretic karyotype, restriction fragment length polymorphism analysis, and antifungal susceptibility testing. Pediatric candidal fungemia, arthritis, and their treatments are discussed.

Gallbladder and biliary tract candidiasis

BACKGROUND

The clinical significance of Candida spp isolated from the gallbladder on the biliary tract is relatively unknown.

METHODS

To provide this information, patients with Candida spp isolated from gallbladder and other biliary tract sources during a 10-year period were identified through the records of our clinical microbiology laboratory. Medical records were analyzed for biliary disease causes, culture data, treatment, and outcome.

RESULTS

Twenty-seven patients were identified. Five of seven patients with cholecystitis were critically ill intensive care unit (ICU) patients in whom the mortality rate was 100%. Gallstone pancreatitis was found in four patients and was fatal in one patient with a pancreatic abscess and ongoing retroperitoneal sepsis. An external biliary shunt/endoprosthesis was placed in 16 patients to relieve biliary obstruction. Cholangitis was present in 14 patients, and most bile cultures contained Candida as part of a mixed flora. Only 3 of 27 patients had candidemia, and 22 of 27 patients were colonized with Candida at other sites.

CONCLUSIONS

(1) The ICU patient with Candida cholecystitis has a grave prognosis. (2) Patients with Candida isolated from biliary stents placed for obstruction and cholangitis should be treated with both antifungal and broad spectrum antimicrobial agents. (3) Candidemia is not frequently seen in this setting.

[Epidemiology of invasive mycoses. Experience of a university hospital center in Paris]

The incidence of opportunistic fungal infections have dramatically increased during the past decades. Data from a retrospective study conducted between January 1992 and December 1994 in Necker-Enfants Malades Hospital and a review of the literature were analyzed to assess the main epidemiological features of these infections. Candidiasis remained largely the most frequent: candidemia and invasive candidiasis were diagnosed in respectively 71 and 11 patients. Candida albicans was the agent the most frequently isolated from these infections. However, its percentage was not over 49.35% in our experience. In at least 13 of 27 cases, candidemia could be related to a colonized indwelling catheter. Though less frequent (24 cases), invasive aspergillosis is of major concern considering its mortality. A wider clinical spectrum was observed with sub-necrotizing aspergillosis reported in non-neutropenic immunocompromised patients (five cases) and invasive aspergillosis in AIDS patients (two cases). Among the 14 cases of cryptococcosis, 11 were diagnosed in AIDS patients whereas the other three were observed in renal transplant recipients. Beside these three major fungal infections, deep immunosuppression, notably induced by bone marrow transplantation, favored the emergence of newly fungal opportunistic agents such as Fusarium sp (two cases), Scedosporium apiospermum (one case) and Trichosporon sp (one case).

Fluconazole versus amphotericin B in the treatment of hematogenous candidiasis: a matched cohort study

PURPOSE

To compare the efficacy and toxicity of fluconazole and amphotericin B in the treatment of hematogenous candidiasis in cancer patients.

PATIENTS AND METHODS

A matched cohort study of cancer patients with hematogenous candidiasis was conducted. Forty-five patients with hematogenous candidiasis who received fluconazole (200 to 600 mg/day) in an open-label trial at the University of Texas M. D. Anderson Cancer Center, Houston, Texas, between February 1990 and June 1992 were matched to 45 patients treated with amphotericin B (0.3 to 1.2 mg/kg/day) for the same diagnosis. Criteria for matching included the following prognostic variables at the initiation of therapy: pneumonia, neutropenia (< 1,000 cells/mm3), number of positive blood cultures before therapy, infecting Candida species, underlying disease, and the simplified acute physiology score. Response and survival at 48 hours, after 5 days of therapy, and at the end of therapy, as well as toxicity rates were obtained. Other post hoc analyses were performed. Differences in outcomes were assessed by the McNemar, the sign, and the log rank tests.

RESULTS

Patients were similar with respect to the matching criteria, age, sex, status of underlying disease, use of antibiotics and growth factors, duration of treatment, presence and removal of central venous catheters, disseminated disease, and concomitant infections. Response rates at 48 hours and 5 days were similar between the two study groups. Overall response rates at the end of therapy were 73% for patients treated with fluconazole and 71% for patients treated with amphotericin B (P = 0.78). There were no differences in survival rates or causes of death. Toxicity was observed in 9% of patients treated with fluconazole and in 67% of patients treated with amphotericin B (P < 0.0001). Toxic effects of amphotericin B included nephrotoxicity, hypokaliemia, and fever and chills.

CONCLUSION

Fluconazole is effective and better tolerated than amphotericin B for the treatment of hematogenous candidiasis in cancer patients.

Is there a therapeutic or pharmacokinetic rationale for amphotericin B dosing in systemic Candida infections?

OBJECTIVE

To review the literature regarding the dosage of amphotericin B in Candida infections. The correlation or rationale of current dosing practices is assessed in light of the literature.

DATA SOURCES

A MEDLINE search encompassing the years 1968-1995 was used to identify pertinent literature. Additional references were obtained from the articles retrieved from MEDLINE.

STUDY SELECTION

Studies that directly assessed amphotericin B dosage and/or duration, pharmacokinetic literature dealing with plasma concentrations and amphotericin B disposition, and literature dealing with dose and/or concentration as well as clinical outcome were selected for inclusion. Additional relevant citations were used in the introductory material and discussion.

DATA EXTRACTION

Although there was a large number of articles related to amphotericin B, surprisingly few large studies were designed to address the issues in question. The description of the methods and results of these heterogeneous articles are the basis of this review. Although additional controlled studies with more subjects need to be performed, the results to date provide a foundation from which to make some inferences regarding optimal use of this therapeutic modality until more definitive data become available.

DATA SYNTHESIS

Despite numerous articles addressing the pharmacokinetics of amphotericin B, little is known about its tissue distribution, the rate of transfer of the drug from vascular to peripheral sites, or its terminal disposition. Less information is available regarding the relevance of pharmacokinetic parameters or serum concentrations to clinical outcome. Most of the articles mentioning dosing provide little or no justification for the doses employed. The variety of the dosages used and the heterogeneity of the populations studied make determination of dose-outcome relationships difficult.

CONCLUSIONS

From the available clinical data, it appears that early initiation of amphotericin B therapy is crucial to a favorable outcome. Daily dosing initially followed by every-other-day administration of twice the daily dose is better tolerated by the patient than daily dosing and produces a similar therapeutic outcome. The drug should be continued until therapeutic endpoints have been achieved, rather than until a specific total dosage has been administered. The nephrotoxicity that occurs with amphotericin B administration is apparently reversible and should not be used as an endpoint for therapy if total dosages do not exceed 4 g. Additional well-designed, controlled trials evaluating standardized dosing methods of amphotericin B with predetermined dosing regimens and/or definitive therapeutic endpoints are needed to determine the optimal dosing approach for this agent.

The changing face of candidemia: emergence of non-Candida albicans species and antifungal resistance

OBJECTIVES

To assess the changing epidemiology of candidemia in the 1990s, to evaluate the clinical implications for the presence of non-Candida albicans in blood, and to evaluate the presence of antifungal resistance in relation to prior antifungal administration.

DESIGN

Multicenter prospective observational study of patients with positive blood cultures for Candida species or Torulopsis glabrata.

SETTING

Four tertiary care medical centers.

RESULTS

Four hundred twenty-seven consecutive patients were enrolled. The frequency of candidemia due to non-C. albicans species significantly increased in each hospital throughout the 3.5-year study period (P = 0.01). Thirteen percent of candidemias occurred in patients who were already receiving systemic antifungal agents. Candidemias developing while receiving antifungal therapy were more likely caused by non-C. albicans species than by C. albicans species (P = 0.0005). C. parapsilosis and C. krusei were more commonly seen with prior fluconazole therapy, whereas T. glabrata was more commonly seen with prior amphotericin B therapy. Candida species isolated during episodes of breakthrough candidemia exhibited a significantly higher MIC to the antifungal agent being administered (P < 0.001).

CONCLUSION

In this large scale study, the non-C. albicans species, especially T. glabrata, emerged as important and frequent pathogens causing fungemia. This finding has major clinical implications given the higher complication and mortality rate associated with the non-C. albicans species. The change in the pattern of candidemia might be partly attributed to the increase in number of immunocompromised hosts and the widespread use of prophylactic or empiric antifungal therapy. This is an ominous sign given the in vitro resistance of the non-C. albicans species to currently available antifungal agents.

Recent progress and current problems in treatment of invasive fungal infections in neutropenic patients

Invasive fungal infections, including disseminated candidiasis and invasive pulmonary aspergillosis, are important causes of morbidity and mortality in neutropenic patients. The recent development of fluconazole, itraconazole, lipid formulations of amphotericin B, and recombinant cytokines have expanded our therapeutic armamentarium. Clinical trials have elucidated new strategies for utilizing these compounds in the prevention and treatment of opportunistic mycoses. The population of more severely immunocompromised patients, however, continues to expand and the spectrum of drug-resistant fungi, including but not limited to Candida spp, Fusarium spp, Zygomycetes, and dematiaceous moulds, continues to evolve, thus presenting new challenges to recent therapeutic advances. Development of new antifungal chemotherapeutic agents and novel approaches for augmentation of host response will be required to meet these new mycologic challenges.

Catheter-related complications of cancer therapy

Although the management of CVC-related infection appears complex and at times the literature seems to be contradictory, simple guidelines can direct the clinician in a stepwise fashion. Knowledge of the pathogenesis of each organism and the immune status of the host is crucial to decide whether catheter removal or retention is indicated. For example, in general, GNB bacteremia does not immediately prompt catheter removal in a neutropenic patient but does in a nonneutropenic host because of the gastrointestinal source of the former and a primary catheter source in the latter. In summary, as more CVCs are inserted in patients undergoing chemotherapeutic, antimicrobial, transfusional, and nutritional supportive care, novel approaches to prevention and treatment of the associated infectious complications inherent with such devices are needed. A multifaceted approach from impregnated catheters to local catheter-site antisepsis was reviewed. We may find, however, that as simple handwashing between patients is crucial to infection control, so too is a trained catheter-care team using total barrier precautions and ensuring proper local catheter maintenance critical to preventing CVC-related infections.

Emerging fungal infections in cancer patients

The increasing number of reports in cancer patients that describe unusual or new fungal pathogens in severe systemic infections may be due, in part, to new treatment regimens but also to increased recognition of clinical disease by physicians and unusual organisms by microbiologists. Identification of these pathogens requires specialized expertise but the diagnosis may often be too late to permit effective therapeutic intervention. An unfortunate limitation of current antifungal agents is their limited efficacy in the heavily immunosuppressed, even when the drugs show good activity in vitro. Infections with Candida spp., and non-Candida yeasts and moulds are often disseminated and are frequently fatal in patients with severe immunosuppression. Therapeutic outcomes could be improved with more precise and rapid diagnostic procedures, standardized treatments for each pathogen and improved therapeutic agents. Liposomal amphotericin B formulations, new azole antifungals, more aggressive surgery and haemopoietic growth factors may improve the poor outcome that currently occurs with many of those infections.

Mixed oropharyngeal candidiasis due to Candida albicans and non-albicans Candida strains in HIV-infected patients

In order to determine the clinical significance of mixed oropharyngeal candidiasis (Candida albicans plus a non-albicans strain of Candida) in patients infected with HIV-1, a retrospective chart review was done in 12 HIV-1-infected patients with a clinical episode of oropharyngeal candidiasis, in whom a mixed culture of Candida albicans (found to be fluconazole-sensitive) plus a non-albicans species of Candida was obtained from their oral cavities. This group was compared with 26 HIV-positive patients (control group) with oropharyngeal candidiasis due to Candida albicans (found to be fluconazole-sensitive). Antifungal susceptibility testing was performed by a broth microdilution test with RPMI-2% glucose. A fungal strain was considered fluconazole-sensitive if its MIC was < 0.5 micrograms/ml. Both the study and control groups had similar clinical and demographic characteristics. All the patients were severely immunocompromised, with a mean CD4+ lymphocyte count of 63/mm3 (95% CI 41-84) and 80/mm3 (95% CI 25-135) in the study and control groups, respectively. In the study group, seven patients had Candida albicans and Candida krusei in their oral cavity, four had Candida albicans and Candida glabrata, and one had Candida albicans and Candida tropicalis. Antifungal therapy consisted of ketoconazole (5 patients in the study group, 14 in the control group) or fluconazole (7 patients in the study group, 12 in the control group); no statistically significant difference in clinical outcome was observed. Fungal strain persistence after therapy was frequently observed in both groups. It is concluded that non-albicans strains of Candida, less sensitive to azole drugs than their Candida albicans counterparts, are not clinically relevant in episodes of mixed oropharyngeal candidiasis in HIV-1-infected patients.

Candida endophthalmitis in non-neutropenic critically ill patients

Six non-neutropenic critically ill patients who developed hematogenous endophthalmitis due to Candida spp. were studied prospectively. In all cases the yeast was isolated in blood cultures. The incidence of endophthalmitis in patients with candidemia was 13%, the predominant species being Candida albicans. Four patients were treated with fluconazole, but its efficacy could not be evaluated because three of the patients died. In patients at risk of candidemia, regular ophthalmoscopic examinations are recommended in order to enable early initiation of systemic antifungal therapy in those who develop endophthalmitis.