Fluconazole prophylaxis against fungal colonization and infection in preterm infants

Genotyping analysis of colonizing candidal isolates from very-low-birthweight infants in a neonatal intensive care unit

To analyse the relatedness of colonizing candidal isolates from very-low-birthweight infants hospitalized in a neonatal intensive care unit (NICU), we prospectively collected 86 candidal isolates from 20 infants, including 67 isolates of Candida albicans from 15 infants, 17 isolates of Candida parapsilosis from five infants and two isolates of Candida glabrata from one infant, who also had C. albicans colonization, over a one-year period. All 86 isolates were genotyped by infrequent-restriction-site polymerase chain reaction (IRS-PCR) and electrophoretic karyotyping (EK) with pulsed-field gel electrophoresis. A total of 15 genotypes were identified by IRS-PCR and 12 genotypes by EK. Some infants shared a common genotype. From a single infant, an identical genotype was found in 11 of 13 cases where at least two isolates of same Candida species were available for genotyping analysis, regardless of anatomical site, how many isolates were recovered or how many times. Should an infant harbour a candidal strain, they may harbour this strain at multiple sites and for a prolonged period.

Impact of fluconazole prophylaxis on cortisol levels in critically ill surgical patients

Fluconazole is widely used in the intensive care unit for prevention and treatment of fungal infections. Case reports have described an association between fluconazole and adrenal dysfunction, an important cause of morbidity and mortality in critically ill patients. We sought to determine whether 400 mg of fluconazole per day administered to critically ill surgical patients was associated with a reduction in cortisol levels. Cortisol levels were measured in stored plasma specimens drawn from 154 critically ill surgical patients randomized in 1998-1999 to receive fluconazole or placebo for the prevention of candidiasis. The primary outcome measure was the median plasma cortisol level > or =1 day after study drug initiation (MPCL). Secondary outcomes were adrenal dysfunction, defined as an MPCL of <15 microg/dl, changes in cortisol levels over time, and mortality. The median MPCL was 15.75 microg/dl (interquartile range [IQR], 11.65 to 21.33 microg/dl) in 79 patients randomized to fluconazole and 16.71 microg/dl (IQR, 11.67 to 23.00 microg/dl) in 75 patients randomized to placebo (P = 0.52). Patients randomized to fluconazole did not have significantly increased odds of adrenal dysfunction compared to patients randomized to placebo (odds ratio, 0.98; 95% confidence interval, 0.48 to 2.01). Randomization to fluconazole was not associated with a significant difference in cortisol level changes over time. Mortality was not different between patients with and without adrenal dysfunction, nor was it different between patients with adrenal dysfunction who were randomized to fluconazole and those randomized to placebo. Fluconazole prophylaxis in this population of critically ill surgical patients did not result in significant adrenal dysfunction.

Risk factors associated with candidaemia in the neonatal intensive care unit: a case-control study

The incidence of candidaemia is steadily increasing in neonatal intensive care units (NICUs). Several neonatal risk factors for candidaemia have been identified, however, the number of cases in controlled studies is small and knowledge concerning maternal and perinatal risk factors is limited. The present study attempted to identify modifiable, independent maternal, perinatal and neonatal risk factors for candidaemia using a retrospective case-control study in the NICU of a tertiary-care paediatric medical centre. The study group consisted of 56 neonates admitted to the NICU between 1996 and 2000 who acquired candidaemia. The control group comprised the first infant admitted immediately after each study infant matched for gestational age (+/-10 days) and birthweight (+/-200 g). Potential maternal, perinatal and neonatal risk factors were compared between the groups using statistical methods and analysed by univariate and multivariate stepwise logistic regression models. The independent risk factors found to be significantly associated with increased risk of candidaemia were duration of ventilation and presence of bacteraemia before candidaemia. Maternal steroids had a significant protective effect. The positive predictive value using these three parameters was 78.38%. Maximizing in-utero steroid treatment in high-risk pregnancies, minimizing the days of mechanical ventilation and investment of efforts in prevention of bacteraemia may help to reduce the incidence of candidaemia in the NICU.

Antifungals in systemic neonatal candidiasis

Fungal infections are common in the newborn period, especially among premature neonates, and are responsible for considerable morbidity and mortality. Currently, three classes of antifungals are commonly used in the treatment of systemic fungal infections in neonates: the polyene macrolides (e.g. amphotericin B [deoxycholate and lipid preparations]); the azoles (e.g. fluconazole); and the fluorinated pyrimidines (e.g. flucytosine). The echinocandins (e.g. caspofungin and micafungin) are a newer class of antifungals which shows promise in this population.The available kinetic data on amphotericin B deoxycholate in neonates are derived from very small studies and exhibit considerable variability. There are no kinetic data available for the use of lipid preparations in this population and, again, much has been inferred from adult studies. The information available for flucytosine is also limited but appears similar to what is observed in adults. Fluconazole has the most neonatal pharmacokinetic data, which show slightly less variability than the other antifungals. Genomic factors which affect the metabolism of amphotericin B and fluconazole may explain some of the observed variability. Most of the data for the efficacy of antifungal drugs in neonates are derived from retrospective studies and case reports. The data for amphotericin B deoxycholate and flucytosine are limited. There are more data for the liposomal and lipid complex preparations of amphotericin B and for fluconazole in this population. These support the use of these drugs in neonates, but because of their largely noncomparative nature they can not define the optimal dosage or duration of therapy. Amphotericin B deoxycholate is primarily nephrotoxic. It also induces electrolyte abnormalities and is to a lesser degree cardiotoxic. This toxicity in neonates appears similar to published data in older children and adults. While the lipid preparations of amphotericin B owe their existence to a presumed decrease in toxicity, the observed toxicity in neonates appears to be equal to that seen with the deoxycholate, although it should be noted that the lipid preparations are usually given at much higher dosages. Fluconazole toxicity appears to be milder and less frequent in this population than is seen with amphotericin B. In the final analysis, we do not have sufficient data to define the pharmacokinetic profiles, optimal dose or duration of therapy, or toxicity for any of these compounds in neonates. Further studies are necessary if the optimisation of antifungal therapy in this population is to continue.

Controversies in neonatal infection

Antibiotics are an important part of neonatal care, but we must be careful that a short-sighted approach to their use does not magnify the problems they are designed to prevent. Prevention of infections by good infection control practices and minimizing risk factors for sepsis is just as important as appropriate antibiotic use. Attempts to eradicate colonizing organisms of low virulence may result in their replacement by more problematic organisms, so over-vigorous use of antibiotics to try to prevent infections is not always wise.

Fungal infection in the very low birthweight infant

PURPOSE OF REVIEW

Fungal infections are prevalent in very low birthweight (<1500 g) infants and are associated with significant morbidity and mortality. A better understanding of the adherence factors, molecular diagnostics and risk factors for invasive fungal infection are important in treatment and prevention.

RECENT FINDINGS

Animal studies have demonstrated that Candida readily adheres to apical microvilli and the junctions between enterocytes. Although antibiotics facilitate colonization, dissemination occurs with immunosuppression. The INT1 gene is associated with enhanced colonization and dissemination in these animal models. Dissemination is probably caused by yeast cell adherence and invasion, whereas tissue injury may be related to filamentous formation. Polymerase chain reaction techniques have demonstrated promise in neonatal patients and may not only detect bloodstream infection, but fungal infection at other sites. At the time of fungal sepsis, less than 28 weeks' gestation, thrombocytopenia, and previous exposure to broad-spectrum antibiotics continue to be risk factors for infection. Empiric therapy is still being defined and investigated. Fluconazole prophylaxis should be strongly considered in the most immature infants.

SUMMARY

Preventative strategies against fungal colonization and infection are critical in high-risk very low birthweight infants. Also promising is the ability of molecular diagnostics to detect infection earlier, allowing for prompt treatment, including central venous catheter removal. Identifying the highest risk very low birthweight infants for prophylaxis and empiric therapy may lead to better outcomes. Multicenter clinical trials of fluconazole prophylaxis to confirm its safety and efficacy, and of empiric treatment to test safety and outcomes are urgently needed.

Prevention and treatment of nosocomial sepsis in the NICU

Nosocomial sepsis is a serious problem for neonates who are admitted for intensive care. It is associated with an increase in mortality, morbidity, and prolonged length of hospital stay. Thus, both the human and fiscal costs of these infections are high. Although the rate of nosocomial sepsis increases with the degree of both prematurity and low birth weight, no specific lab test has been shown to be very useful in improving our ability to predict who has a "real" blood-stream infection and, therefore, who needs to be treated with a full course of antibiotics. As a result, antibiotic use is double the rate of "proven" sepsis and we are facilitating the growth of resistant organisms in the neonatal intensive care unit. The purpose of this article is to describe simple changes in process, which when implemented, can reduce nosocomial infection rates in neonates and improve outcomes.

Resistant Candida parapsilosis associated with long term fluconazole prophylaxis in an animal model

We report an increased occurrence of fluconazole-resistant Candida parapsilosis after a 4-year period of antifungal prophylaxis in a premature animal neonatal intensive care unit. Although prevention of nosocomial fungal infections in premature infants is desirable, implementation of fluconazole prophylaxis should be undertaken with caution. Where such programs are in place, evaluation of fungal isolates for drug resistance should be considered.

Clinical microbiology of bacterial and fungal sepsis in very-low-birth-weight infants

Twenty percent of very-low-birth-weight (<1500 g) preterm infants experience a serious systemic infection, and despite advances in neonatal intensive care and antimicrobials, mortality is as much as threefold higher for these infants who develop sepsis than their counterparts without sepsis during their hospitalization. Outcomes may be improved by preventative strategies, earlier and accurate diagnosis, and adjunct therapies to combat infection and protect the vulnerable preterm infant during an infection. Earlier diagnosis on the basis of factors such as abnormal heart rate characteristics may offer the ability to initiate treatment prior to the onset of clinical symptoms. Molecular and adjunctive diagnostics may also aid in diagnosing invasive infection when clinical symptoms indicate infection but no organisms are isolated in culture. Due to the high morbidity and mortality, preventative and adjunctive therapies are needed. Prophylaxis has been effective in preventing early-onset group B streptococcal sepsis and late-onset Candida sepsis. Future research in prophylaxis using active and passive immunization strategies offers prevention without the risk of resistance to antimicrobials. Identification of the differences in neonatal intensive care units with low and high infection rates and implementation of infection control measures remain paramount in each neonatal intensive care unit caring for preterm infants.

Novel approaches to antifungal prophylaxis

Antifungal prophylaxis represents a significant advance in the management of patients at risk from fungal infections in a variety of settings. Identification of patients at the highest risk and the utilisation of safe and effective drugs maximises the benefits of prophylaxis. Situations in which antifungal prophylaxis has been shown to be useful are bone marrow transplantation, liver and lung transplantation, surgical and neonatal intensive care units, secondary prophylaxis of fungal infections associated with HIV and neutropenia associated haematological malignancies and their treatment. New antifungal agents, such as the echinocandins and the new azoles, are available and have a potential role in antifungal prophylaxis. Future studies should evaluate which strategy is more useful; prophylaxis or pre-emptive therapy.

Mixed infection with unusual fungi and staphylococcal species in two extremely premature neonates

Systemic fungal infections are being recognized with increasing frequency in extremely premature neonates. We report two such infants with late-onset mixed infection with Staphylococcal species and unusual fungi. These cases are of interest in view of recent reports on the interaction of Staphylococcal cell wall components and neutrophils, as damaged skin sites could form a nidus and portal of entry for saprophytic fungal pathogens. It is also important to consider fungal infection as a possibility in sick premature infants with necrotic skin lesions even when the systemic signs have an alternative explanation with ongoing bacteremia.

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

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

Comparison of the susceptibilities of Candida spp. to fluconazole and voriconazole in a 4-year global evaluation using disk diffusion

From June 1997 to December 2001, results of in vitro susceptibility tests of yeast isolates from 35 countries were collected. For 2001 alone, fluconazole results were reported for 22,111 yeast isolates from 77 institutions in 30 countries. Of these isolates, 18,569 were also tested for susceptibility to voriconazole. All study sites tested clinical yeast isolates by recently endorsed NCCLS disk diffusion method M44-P. Disk test plates were automatically read and results were recorded with the BIOMIC Image Analysis System. Species, drug, zone diameter, susceptibility category, MIC, and quality control results were electronically submitted by e-mail quarterly for analysis. Duplicate test results (same patient and same species with same sensitivity-resistance profile and biotype results during any 7-day period) and uncontrolled test results were eliminated from this analysis. The proportion of Candida albicans isolates decreased from 69.7% in 1997 to 1998 to 63.0% in 2001, and this decrease was accompanied by a concomitant increase in C. tropicalis and C. parapsilosis. The susceptibility (susceptible [S]or susceptible-dose dependent [S-DD]) of C. albicans isolates to fluconazole was virtually unchanged, from 99.2% in 1997 to 99% in 2001; the C. glabrata response to fluconazole was unchanged, from 81.5% S or S-DD in 1997 to 81.7% in 2001, although the percentage of resistant isolates from blood and upper respiratory tract samples appeared to increase over the study period; the percentage of S C. parapsilosis isolates decreased slightly, from 98% S or S-DD in 1997 to 96% in 2001; and the percentage of S isolates of C. tropicalis increased slightly, from 95.7% in 1997 to 96.9% in 2001. The highest rate of resistance to fluconazole among C. albicans isolates was noted in Ecuador (7.6%, n = 250). Results from this investigation indicate that the susceptibility of yeast isolates to fluconazole has changed minimally worldwide over the 4.5-year study period and that voriconazole demonstrated 10- to 100-fold greater in vitro activity than fluconazole against most yeast species.

Prophylactic intravenous antifungal agents to prevent mortality and morbidity in very low birth weight infants

BACKGROUND

Invasive fungal infection is an increasingly common cause of mortality and morbidity in very low birth weight infants. As the diagnosis is often difficult, and treatment is often delayed, there is a need to assess whether antifungal prophylaxis is beneficial.

OBJECTIVES

To assess whether prophylactic intravenous antifungal therapy reduces mortality and adverse neurodevelopmental outcomes in very low birth weight infants.

SEARCH STRATEGY

We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2003), MEDLINE (1966 - October 2003), EMBASE (1980 - October 2003), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised controlled trials that compared the effect of prophylactic intravenous antifungal therapy versus placebo, or no drug, or another antifungal agent, in very low birth weight infants.

DATA COLLECTION AND ANALYSIS

We extracted the data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by each author, and synthesis of data using relative risk and risk difference. The pre-specified outcomes were death prior to hospital discharge, longer term neurodevelopment, incidence of invasive fungal infection, emergence of antifungal resistance, and adverse drug reactions.

MAIN RESULTS

We identified three eligible trials enrolling a total of 214 infants. Each of the trials compared the effect of prophylactic intravenous fluconazole versus placebo. Two of the trials reported death prior to hospital discharge as an outcome. 29 of the 203 infants recruited to these studies died. Meta-analysis revealed a statistically significantly reduced risk of death prior to hospital discharge for the infants who received fluconazole prophylaxis: typical relative risk: 0.44 (95% confidence interval 0.21, 0.91); typical risk difference: -0.11 (95% confidence interval -0.21, -0.02); number needed to treat: 9 (95% confidence interval 5, 50). None of the trials reported data on longer term outcomes.

REVIEWER'S CONCLUSIONS

We have found some evidence that prophylactic intravenous fluconazole reduces mortality prior to hospital discharge in very low birth weight infants. The meta-analysis suggests that there will be one fewer death in every nine infants treated with this intervention, but the 95% confidence interval around this estimate of effect is wide. The longer term neurodevelopmental consequences for infants exposed to this intervention remain to be determined. It will be important to identify any subgroups of very low birth weight infants that receive the most benefit from this intervention. There is also a need for further data on the effect of the intervention on the emergence of organisms with stable antifungal resistance.

Prophylactic oral antifungal agents to prevent systemic candida infection in preterm infants

BACKGROUND

Systemic fungal infection has increased in prevalence in neonatal intensive care units (NICU) caring for very low birth weight infants. It is associated with a prolonged stay and an increase in morbidity and mortality. An assessment of the use of oral prophylactic antifungals to prevent systemic infection is needed.

OBJECTIVES

To assess whether the prophylactic administration of oral antifungal agents to very preterm infants reduces the occurrence of systemic fungal infection.

SEARCH STRATEGY

The standard methods of the Cochrane Collaboration and its Neonatal Review Group were used. Searches were carried out up to July 2003 on the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library Issue 2, 2003), MEDLINE from 1966, EMBASE from 1980, CINAHL from 1992. Abstracts from SPR (1993 - 2003) and ESPR (1995 to 2002) were hand searched.

SELECTION CRITERIA

Randomized and quasi randomized controlled trials in very low birth weight or very preterm infants in which an oral antifungal agent was compared with placebo or no treatment or another oral antifungal agent

DATA COLLECTION AND ANALYSIS

Data were extracted using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of the trial quality and data extraction undertaken by each author. Results were reported using relative risk (RR) and risk difference (RD) and weighted mean difference (WMD). 95% confidence intervals were reported.

MAIN RESULTS

We identified three eligible trials, one comparing nystatin with no treatment (67 infants), one comparing miconazole with placebo (600 infants), and one comparing nystatin with fluconazole (21 infants). As the two trials comparing nystatin or miconazole with placebo or no treatment were clinically quite different, meta-analysis was not performed. In the trial of nystatin versus no treatment, systemic fungal infection was significantly reduced [RR 0.19 (0.04,0.78)] in the group treated with nystatin. In the study comparing miconazole with placebo there was no significant effect on systemic fungal infection [RR 1.32 (0.46,3.75)]. Neither study found a significant effect on mortality, and there was no significant difference in the mean number of days infants received ventilation or stayed in the neonatal intensive care unit. In the small trial comparing oral fluconazole with nystatin, no significant difference in systemic fungal infection [RR 0.17 (0.01, 2.84)] or mortality [RR 0.17 (0.01, 2.84)] was reported. Adverse drug reactions were not reported in any study.

REVIEWER'S CONCLUSIONS

There is insufficient evidence to support the use of prophylactic oral antifungal agents in very low birth weight infants in the neonatal intensive care unit. Randomised controlled trials in current neonatal practice settings are needed, comparing oral antifungal agents with placebo and with each other and including an assessment of side effects, in order to determine whether oral antifungal agents have a role in preventing systemic fungal infections in preterm infants.

Antifungal prophylaxis with azole derivatives

In recent years, several reports have underlined the increasing role of fungal infections as a cause of morbidity and mortality in hospitalised patients. For this reason, and also in light of the high mortality rate associated with these infections, chemoprophylaxis has been advocated by several authors. The available evidence suggests that both fluconazole and itraconazole are able to decrease candida colonisation and infection, when compared with placebo or with nonabsorbable antifungals. Data seem also to suggest that a decrease in fungus-related mortality can be achieved with prophylaxis, although with little effect on overall mortality, probably because of the importance of severe underlying diseases. Itraconazole proved to be effective in the prevention of fungal infections, including invasive aspergillosis, although with increased incidence of side-effects, often leading to treatment discontinuation. The other side of the coin is that antifungal prophylaxis might have untoward effects, such as the selection of triazole-resistant Candida strains or the induction of resistance. In addition, some authors have suggested that the use of triazoles might modulate the pattern of infecting organisms in cancer patients, increasing the risk of both aspergillosis and bacteremia. In conclusion, antifungal prophylaxis with triazole antifungals should be used with caution, only in patients at high risk for invasive fungal infections. These include allogeneic bone marrow transplant patients (especially those with mismatched or unrelated donors), acute myeloid leukaemia patients treated with high-dose cytarabine (C-ara), very-low-birth-weight infants, patients with chronic granulomatous disease, and high-risk surgical and intensive-care unit patients.

Management of candidiasis Management of Candida species infections in critically ill patients

Invasive candidiasis is a feared infection with mortality similar to that of septic shock (40-60%). Improved knowledge of its pathophysiology and the availability of new compounds for antifungal therapy and prophylaxis have contributed to improving the prognosis of severe candidal infections among immunosuppressed patients at the possible cost of the emergence of non-albicans strains of candida with lower susceptibility to azoles. This review focuses on the management of invasive deep-seated candidiasis in critically ill, non-immunocompromised patients. We discuss antifungal use, indications, potential benefit, and main secondary effects. Prevention strategies include pre-emptive antifungal therapy and azole-based prophylaxis. For patients at lower initial risk, pre-emptive therapy should be based on a management strategy that takes into account the presence of definite risk factors and the dynamics of candida colonisation. Among critically ill patients, azole prophylaxis is effective and is not associated with acquisition of resistance; it must be restricted to highly selected groups of patients at high risk only.

The global epidemiology of invasive Candida infections—is the tide turning?

Invasive candidiasis is a condition of major medical importance. Its incidence has increased dramatically over the last 50 years, reflecting increasingly interventional standards of medical care. Candida spp. are regularly reported to be the fourth commonest cause of bloodstream infection, and it is perceived that the incidence of invasive Candida spp. infections continues to increase. The global disease burden of invasive Candida spp. infections is difficult to quantify because of wide geographic variation. Data originating from the United States indicate that mortality from candidiasis has been falling since 1989. Data from several locations have shown that the dramatic increases in Candida spp. bloodstream infections seen during the 1980s were not sustained through the 1990s. Some authors have reported a decreasing incidence. The contribution of non-albicans Candida spp. to invasive infection is rising. Invasive infections with Candida spp. continue to represent a major economic burden, increasing both mortality and morbidity in an already expensive group of hospital patients. There remains much scope for ongoing and future research into the epidemiology and basic disease processes underlying these infections.

Antifungal pharmacotherapy for neonatal candidiasis

Candida is a leading cause of late onset infection (> 3 days of age) in the premature infant. Therefore, decisions about the diagnosis and management of infections caused by Candida are commonplace in the neonatal intensive care unit. Despite this fact, there are few comparative trials about treatment of neonatal Candida infections to guide the practitioner. New antifungals have been developed in the past decade and some clinical experience has been reported that can be used to guide the treatment of infants with serious Candida infections. This article reviews recent pertinent data with regard to dosing guidelines, efficacy, and toxicities of available systemic antifungal agents in the newborn.

Candida bloodstream infection in neonates

Neonatal candidemia is poorly understood and is a leading cause of nosocomial infectious mortality in the nursery. Prevention of candidemia has been difficult, although a combined approach of antifungal prophylaxis and targeted empirical therapy may eventually reduce morbidity and mortality. Multicenter prospective testing of an integrated approach to early diagnosis of neonatal candidemia using newer molecular techniques is also needed. Candidemia in the infant is cause for prompt removal (or replacement) of central vascular catheters and institution of antifungal therapy. End-organ evaluation is also probably warranted to guide treatment and facilitate prognostication. Given the continuing progress in clinical research infrastructure and development of new diagnostic tests and antifungal agents, substantial improvement in the prevention, diagnosis, and management of neonatal candidemia is plausible over the next decade.

Epidemiologia das infecções hematogênicas por Candida spp

O gênero Candida spp é responsável por cerca de 80% das infecções fúngicas no ambiente hospitalar e constitui causa relevante de infecções de corrente sanguínea. Nos Estados Unidos da América, Candida spp é a quarta causa mais comum de infecções de corrente sanguínea, respondendo por cerca de 8% dos casos das infecções documentadas neste sítio. Espécies não-albicans respondem hoje por ao menos 50% das infecções invasivas por Candida spp, apresentando peculiaridades de história natural e sensibilidade a antifúngicos. A mortalidade geral de fungemias por Candida spp é da ordem de 40 a 60%, tornado esta complicação infecciosa um grande desafio para os clínicos que trabalham em hospitais terciários em diferentes países.

Strategies for prevention of neonatal invasive candidiasis

A single-center randomized, placebo-controlled trial has found that intravenous fluconazole prophylaxis in preterm infants < or = 1,000 g with a central venous catheter or endotracheal tube until such infants no longer required intravenous access or attained 6 weeks postnatal age was effective in preventing fungal sepsis. Infants at high risk for fungal sepsis are preterm infants < or = 32 weeks' gestation with one or more of the following additional risk factors: receipt of more than 2 antibiotics, third-generation cephalosporins, histamine-2 receptor antagonists, postnatal steroids, parenteral nutrition, or intravenous lipids; central venous catheter, skin disruption, dermatitis, necrotizing enterocolitis, or abdominal surgery. Further study in larger populations is needed to explore whether antifungal chemoprophylaxis or other strategies may be effective in preventing fungal infection in high-risk neonates. Effective prophylaxis strategies will decrease the high mortality and morbidity associated with fungal infection in high risk infants.

Colonization and epithelial adhesion in the pathogenesis of neonatal candidiasis

Candida species are important nosocomial pathogens in the newborn population, particularly among the premature very-low-birth-weight infants in neonatal intensive care units. Candida colonization of the neonatal skin and gastrointestinal tract is an important first step in the pathogenesis of invasive disease. C albicans is the most commonly isolated species in colonized or infected infants. Over the past decade the incidence of both colonization and infection with other Candida species, particularly C parapsilosis, has risen dramatically. Colonization of the infant occurs early in life and is affected by a variety of common practices in neonatal intensive care. Microbial factors also augment colonization, including the ability of Candida to adhere to human epithelium. A better understanding of the complex interactions between host risk factors and virulence traits of colonizing yeast may allow the risk of systemic spread to be reduced in the population of premature infants.

Neonatal candidemia and end-organ damage: a critical appraisal of the literature using meta-analytic techniques

OBJECTIVE

Neonatal candidemia is an increasing cause of infant morbidity and mortality. We evaluated the current medical literature in an effort to critique the literature and to document the reported prevalences of end-organ damage after neonatal candidemia.

METHODS

We analyzed all peer-reviewed articles of neonatal candidemia published in the English language; inclusion criteria included a cohort limited to all neonatal intensive care unit admissions or all episodes of candidemia in neonates. Articles that also incorporated older patients, did not define a numerator and a denominator for at least 1 form of end-organ damage, included patients from other reports, or did not include all episodes of candidemia in the source population were excluded from the analysis.

RESULTS

Thirty-four articles reported episodes of candidemia and mortality; 21 articles reported prevalence for at least 1 form of end-organ damage. Only 4 (19%) of 21 articles reported prevalence for >4 forms of end-organ damage from the following list: endophthalmitis, meningitis, brain parenchyma invasion, endocarditis, renal abscesses, positive cultures from other normally sterile body fluids, or hepatosplenic abscesses. The median reported prevalence of endophthalmitis was 3% (interquartile range [IQR]: 0%-17%), of meningitis was 15% (IQR: 3%-23%), of brain abscess or ventriculitis was 4% (IQR: 3%-21%), of endocarditis was 5% (IQR: 0%-13%), of positive renal ultrasound was 5% (IQR: 0%-14%), and of positive urine culture was 61% (IQR: 40%-76%). The medical literature concerning end-organ evaluation after episodes of neonatal candidemia is heterogeneous and consists largely of single-center retrospective studies. Year that the data were collected and prevalence of neonates infected with Candida albicans were associated with observed heterogeneity.

CONCLUSIONS

Given the heterogeneity of the medical literature, precise estimates of the frequencies of end-organ damage are not possible and a prospective multicenter trial is warranted, but the data from the published literature suggest that the prevalence of neonates with end-organ damage not only is greater than 0 but also is high enough that until such a prospective trial is completed, end-organ studies should be considered before the conclusion of antifungal therapy.

Empirical therapy for neonatal candidemia in very low birth weight infants

OBJECTIVE

Neonatal candidemia is often fatal. Empirical antifungal therapy is associated with improved survival in neonates and patients with fever and neutropenia. Although guidelines for empirical therapy exist for patients with fever and neutropenia, these do not exist for neonates.

METHODS

A multicenter, retrospective, cohort study was conducted of neonatal intensive care unit patients (N = 6172) who had a blood culture (N = 21,233) after day of life 3 and whose birth weight was <or=1250 g. We performed multivariable conditional logistic regression of risk factors for candidemia. From the regression modeling coefficients, we developed a candidemia score.

RESULTS

In multivariable modeling, thrombocytopenia (odds ratio [OR]: 3.56; 95% confidence interval [CI]: 2.68-4.74) and cephalosporin or carbapenem use in the 7 days before obtaining the blood culture (OR: 1.77; 95% CI: 1.33-2.29) were risk factors for subsequent candidemia. Children who were 25 to 27 weeks' estimated gestational age (OR: 2.02; 95% CI: 1.52-3.05) and children who were born at <25 weeks (OR: 4.15; 95% CI: 3.12-6.29) were at higher risk of developing candidemia than were children who were born at >or=28 weeks. We developed a candidemia score on the basis of the ORs from the multivariable model. Children with a candidemia score >or=2 points were classified as having a "positive" score, and a score of >or=2 points had a sensitivity of 85% and a specificity of 47%.

CONCLUSIONS

We developed a clinical predictive model for neonatal candidemia with high sensitivity and moderate specificity for candidemia. On the basis of our model, when a physician obtains a blood culture, the physician should consider providing antifungal therapy to neonates who are <25 weeks' estimated gestational age and to neonates who have thrombocytopenia at the time of blood culture. In addition, if a physician obtains a blood culture from a child who is 25 to 27 weeks' estimated gestational age and is not thrombocytopenic but has a history of third-generation cephalosporin or carbapenem exposure in the 7 days before the blood culture, then the physician should consider administration of empirical antifungal therapy.

Candida infections in the neonate

Candida infections have become an increasingly frequent problem in neonatal intensive care units, particularly among extremely low birth weight infants. Transmission occurs both vertically and horizontally, with Candida albicans and C. parapsilosis as the predominant species. Multiple risk factors have been identified with prior antibiotic exposure, presence of a central line, endotracheal intubation, and prior fungal colonization reported most frequently. The primary site of infection can involve the bloodstream, meninges, or urinary tract, but disease is frequently disseminated to multiple organ systems. Amphotericin is the most commonly used antifungal agent, although fluconazole is being used more frequently. The potential role of antifungal prophylaxis is not yet clearly defined, but has been the topic of recent investigative efforts. The crude mortality rate among neonates with systemic candidiasis remains approximately 30%.

Antifúngicos de uso sistémico

Invasive fungal infection is the infectious complication with highest associated mortality. Until the 90's amphotericin B was the only drug available to treat these infections. Its spectrum of antifungal activity is excellent, but its use is associated with toxicity in many cases. The development of amphotericin B lipid formulations has resulted in a significant decrease in most of the side effects associated with this drug. Triazoles are safe and effective for treating most invasive fungal infections. Fluconazole is an excellent drug for the prevention and treatment of Candida and Cryptococcus infections, itraconazole has good activity against Candida and Aspergillus, and voriconazole has shown to be better than amphotericin B for invasive aspergillosis. Caspofungin belongs to a new group of antifungal agents, the echinocandins, which are very safe and present excellent activity against Candida and Aspergillus.

Prophylaxis, empirical therapy, or pre-emptive therapy of fungal infections in immunocompromised patients: which is better for whom?

Immunocompromised patients are at risk of developing fungal infections. Over time, the incidence of fungal infections and the spectrum of causative organisms have changed. In addition, treatment strategies in this high-risk population have also changed. Traditional approaches (using polyene-based therapy and older azoles), including empirical treatment strategies, have evolved to include prophylaxis in populations at the greatest risk. These strategies, although effective against Candida species, have not really impacted infections caused by Aspergillus spp. With the recent approval of antifungal agents with demonstrated activity against Aspergillus and other mould infections, there is hope for better outcomes in the treatment of established infections. Several agents, with activity against Aspergillus, have been shown to be effective in the empirical setting. The role of these new antifungal agents in the prophylactic setting remains unknown at present, but the potential for reducing Aspergillus infections is promising and requires ongoing study. The other area of significant research in fungal infections has been the search for accurate, non-invasive, rapid diagnostic tests. Over the past year, several publications have indicated that early diagnosis is possible in immunocompromised patients. These new diagnostics have paved the way for a new strategy, called pre-emptive therapy, enabling infected patients to be identified at an earlier stage of infection. This strategy will permit targeted antifungal therapy in those at greatest risk, and will avoid unnecessary, potentially toxic therapy in those not infected. Validations of the various techniques show promise and are reviewed in this paper.

Management of neonatal candidiasis. Neonatal Candidiasis Study Group

OBJECTIVE

To identify areas of consensus and controversy in the management of neonatal candidiasis.

METHODS

A questionnaire was distributed to US-based members of the Pediatric Infectious Diseases Society and a sampling of US neonatologists.

RESULTS

Three hundred eighty evaluable questionnaires were returned (42% of those mailed). Ninety-five percent of respondents have cared for an infant with systemic candidiasis in the past 2 years. Fluconazole and liposomal amphotericin are used to some extent by 90 and 69% of respondents, respectively. A single blood culture positive for Candida led to a recommendation for immediate treatment by 99%; amphotericin B was the preferred therapy for candidemia (88%). More than 80% of respondents would request cerebrospinal fluid, urine and repeat blood cultures and ophthalmologic examination in the evaluation of candidemia. If a cerebrospinal fluid culture is positive, 25% would use amphotericin B alone whereas 62% would add flucytosine. For candiduria Society members chose fluconazole therapy more often than did neonatologists, 23% vs. 3.4% (P<0.001). There was no consensus concerning duration of therapy, use of an amphotericin B test dose or management of a central catheter in place during candidemia.

CONCLUSIONS

Systemic candidiasis in neonates is a frequently encountered clinical problem. There is agreement that prompt therapy with amphotericin B is required if a blood culture is positive for Candida and that such infants require additional evaluations. Other antifungals (fluconazole, liposomal amphotericin B) are used to some extent in this population. Many issues in management have no clear consensus and warrant further research.