Successful caspofungin treatment of multidrug resistant Candida parapsilosis septicaemia in an extremely low birth weight neonate

Candida parapsilosis: from Genes to the Bedside

Patients with suppressed immunity are at the highest risk for hospital-acquired infections. Among these, invasive candidiasis is the most prevalent systemic fungal nosocomial infection. Over recent decades, the combined prevalence of non-albicans Candida species outranked Candida albicans infections in several geographical regions worldwide, highlighting the need to understand their pathobiology in order to develop effective treatment and to prevent future outbreaks. Candida parapsilosis is the second or third most frequently isolated Candida species from patients. Besides being highly prevalent, its biology differs markedly from that of C. albicans, which may be associated with C. parapsilosis' increased incidence. Differences in virulence, regulatory and antifungal drug resistance mechanisms, and the patient groups at risk indicate that conclusions drawn from C. albicans pathobiology cannot be simply extrapolated to C. parapsilosis Such species-specific characteristics may also influence their recognition and elimination by the host and the efficacy of antifungal drugs. Due to the availability of high-throughput, state-of-the-art experimental tools and molecular genetic methods adapted to C. parapsilosis, genome and transcriptome studies are now available that greatly contribute to our understanding of what makes this species a threat. In this review, we summarize 10 years of findings on C. parapsilosis pathogenesis, including the species' genetic properties, transcriptome studies, host responses, and molecular mechanisms of virulence. Antifungal susceptibility studies and clinician perspectives are discussed. We also present regional incidence reports in order to provide an updated worldwide epidemiology summary.

Successful treatment of an infant infected with refractory C. parapsilosis with caspofungin

Neonatal Candida infections are the leading cause of invasive fungal infections that might cause severe morbidity or mortality in a large majority of those affected. Although Candida albicans has been the most common species, Candida parapsilosis is increasingly being recognized as an important cause of invasive candidiasis in neonates. Among the Candida species, C. parapsilosis has been commonly isolated and shown to be less susceptible in vitro to echinocandins than other Candida species. We report an infant who had refractory C. parapsilosis septicemia cured with caspofungin.

Successful caspofungin treatment of persistent candidemia in extreme prematurity at 23 and 24 weeks' gestation

Systemic fungal infection continues to be a major cause of mortality in extremely low-birth-weight premature infants. Amphotericin B has been recommended as the primary treatment; however, its use is limited due to drug-induced nephrotoxicity and amphotericin B-resistant candidemia. Caspofungin therapy was initiated in seven extremely premature infants at 23 and 24 weeks' gestation with persistent systemic candidiasis despite liposomal amphotericin B treatment. The gestational age was 23(+1)-24(+6) weeks, and birth weight was 530-825 g. Of the seven patients, the peripheral blood cultures of six patients were positive for Candida parapsilosis and one had positive culture for Candida albicans. The dosage of caspofungin was 2 mg/kg/day, and the mean treatment duration was 14 days. All of the persistent candidemia resolved on caspofungin therapy. There was no recurrent candidemia after discontinuing caspofungin. There were no adverse effects, hepatotoxicity, nephrotoxicity, anemia, or thrombocytopenia. Caspofungin successfully treated persistent candidemia in extremely premature infants at 23 and 24 weeks' gestational age.

Antifungal agents and therapy for infants and children with invasive fungal infections: a pharmacological perspective

Invasive fungal infections, although relatively rare, are life-threatening diseases in premature infants and immunocompromised children. While many advances have been made in antifungal therapeutics in the last two decades, knowledge of the pharmacokinetics and pharmacodynamics of antifungal agents for infants and children remains incomplete. This review summarizes the pharmacology and clinical utility of currently available antifungal agents and discusses the opportunities and challenges for future research.

Candida parapsilosis is a significant neonatal pathogen: a systematic review and meta-analysis

BACKGROUND

Candida is the third most common cause of late-onset neonatal sepsis in infants born at <1500 g. Candida parapsilosis infections are increasingly reported in preterm neonates in association with indwelling catheters.

METHODS

We systematically reviewed neonatal literature and synthesized data pertaining to percentage of C. parapsilosis infections and mortality by meta-analyses. We also reviewed risk factors, virulence determinants, antimicrobial susceptibility patterns and outlined clinical management strategies.

RESULTS

C. parapsilosis infections comprised 33.47% (95% confidence interval [CI]: 30.02, 37.31) of all neonatal Candida infections. C. parapsilosis rates were similar in studies performed before the year 2000, 33.53% (95% CI: 30.06, 37.40) (28 studies), to those after 2000, 27.00% (95% CI: 8.25, 88.37) (8 studies). The mortality due to neonatal C. parapsilosis infections was 10.02% (95% CI: 7.66, 13.12). Geographical variations in C. parapsilosis infections included a low incidence in Europe and higher incidence in North America and Australia. Biofilm formation was a significant virulence determinant and predominant risk factors for C. parapsilosis infections were prematurity, prior colonization and catheterization. Amphotericin B remains the antifungal drug of choice and combination therapy with caspofungin or other echinocandins may be considered in resistant cases.

CONCLUSION

C. parapsilosis is a significant neonatal pathogen, comprises a third of all Candida infections and is associated with 10% mortality. Availability of tools for genetic manipulation of this organism will identify virulence determinants and organism characteristics that may explain predilection for preterm neonates. Strategies to prevent horizontal transmission in the neonatal unit are paramount in decreasing infection rates.

Candida parapsilosis and the neonate: epidemiology, virulence and host defense in a unique patient setting

Invasive candidiasis is a common problem in premature infants that leads to high morbidity and mortality. Although Candida albicans has historically been the most prominent species involved in these infections and has therefore been the subject of the most study, Candida parapsilosis is increasing in frequency, and neonates are disproportionately affected. This article reviews unique aspects of the epidemiology of this organism as well as strategies for prophylaxis against invasive candidiasis in general. Additionally, important differences between C. parapsilosis and C. albicans are coming to light related to virulence determinants and interactions with components of host immunity. These developments are reviewed while highlighting the significant gaps in our understanding that remain to be elucidated.

Candida glabrata sepsis associated with chorioamnionitis in an in vitro fertilization pregnancy: case report and review

We report a case of Candida glabrata sepsis associated with chorioamnionitis in an in vitro fertilization-assisted pregnancy. There is a strong association between C. glabrata chorioamnionitis and assisted fertility techniques. Candida glabrata chorioamnionitis presents unique management challenges.

A review of clinical experience with newer antifungals in children

Fungal infections are a significant cause of morbidity and mortality in immunocompromised children. Since the beginning of the 21st century, many new antifungals including the echinocandins (i.e., caspofungin, micafungin, anidulafungin) and the newer generation triazoles (i.e., voriconazole and posaconazole) have received Food and Drug Administration approval. Unfortunately, despite making great strides in the adult arena, these agents are not currently approved in the pediatric population. However, pharmacokinetic data and clinical experiences with these agents in infants, children, and adolescents are mounting. As such, this review will discuss key concepts in pediatric pharmacology and clinical use of these newer antifungal agents.

Antifungal therapy for newborn infants with invasive fungal infection

BACKGROUND

A variety of antifungal drugs, drug preparations and drug combinations are available to treat newborn infants with suspected or confirmed invasive fungal infection. There is a need to assess their relative merits.

OBJECTIVES

To assess the effect of treatment with different antifungal drugs, drug preparations or drug combinations on mortality and morbidity in newborn infants with suspected or confirmed invasive fungal infection.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (The Cochrane Library, 2012, Issue 2), MEDLINE, EMBASE, CINAHL (to March 2012), conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised and quasi-randomised control trials comparing one antifungal agent or combination of agents with another in newborn infants with suspected or confirmed invasive fungal infection.

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 risk ratio and risk difference.

MAIN RESULTS

We identified only one small trial in which 24 newborn infants participated. This trial compared the use of fluconazole versus amphotericin B (plus 5-fluorocytosine if fungal meningitis present). The trial did not detect a statistically significant effect on mortality (risk ratio 0.73; 95% confidence interval 0.26 to 2.05).

AUTHORS' CONCLUSIONS

There are insufficient data to inform practice. Large randomised controlled trials are required to compare antifungal drugs, drug preparations or drug combinations for treating newborn infants with invasive fungal infection.

Caspofungin for the treatment of immunocompromised and severely ill children and neonates with invasive fungal infections

Caspofungin is the first member of the echinocandin class of antifungals to receive an indication for the use in infants, children, and adolescents from the United States Food and Drug Administration. Daily doses of 50 mg/m(2) result in pharmacokinetic parameters that are similar to those observed in adults. Although fewer data are available, the response rates in pediatric patients who received caspofungin either as treatment or empiric therapy in clinical trials are similar to those reported in adults. In addition, caspofungin appears to be generally safe and well tolerated in this population. This represents a significant step forward in the treatment of invasive fungal infections within this population, as caspofungin is associated with few clinically significant drug-interactions and toxicities compared to other antifungals, such as the azoles and amphotericin B.

Echinocandin use in the neonatal intensive care unit

OBJECTIVE

To evaluate the literature regarding the use of echinocandins to treat invasive fungal infections caused by Candida spp. in patients in the neonatal intensive care unit.

DATA SOURCES

Literature retrieval was accessed through MEDLINE (Jan 2000-September 2011) using the search terms echinocandin, caspofungin, micafungin, anidulafungin, and neonate with limits for age group (ie, birth to 1 month). Reference citations from identified articles were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

Relevant information on the pharmacokinetics, efficacy, and safety of echinocandins in neonates was selected. Prospective studies, retrospective studies, and case series in English identified from MEDLINE were evaluated.

DATA SYNTHESIS

Neonates, especially preterm neonates, have many risk factors that predispose them for invasive fungal infections caused by Candida spp. To date, the only antifungals recommended for use in neonates for treatment of candidiasis are amphotericin B (deoxycholate or a lipid formulation) and fluconazole; however, the toxicities associated with amphotericin B and resistance of certain Candida spp. to fluconazole limit their use in neonates. There is a need for a broad-spectrum antifungal agent with limited toxicity for use in this patient population. The echinocandins may represent such a class of antifungals. To date, micafungin is the most studied echinocandin in the neonatal population, followed by caspofungin; however, studies evaluating their efficacy and pharmacokinetic parameters in neonates are few.

CONCLUSIONS

Although studies suggest that the echinocandins may have a favorable safety profile, the lack of pharmacokinetic data and standardized study designs limit current recommendations of use of echinocandins as first-line agents in neonates in the treatment of fungal infections. However, if an echinocandin is to be used in this population, the data presented in this review suggest the use of micafungin over the other echinocandins, and higher doses of micafungin (10-15 mg/kg/day) should be used when central nervous system involvement is suspected.

Complicated Candida parapsilosis peritonitis on peritoneal dialysis in a neonate with renal failure because of bilateral adrenal abscesses

We present a full-term female infant with a difficult delivery course complicated with Escherichia coli sepsis and bilateral adrenal abscesses. She developed renal failure and received peritoneal dialysis. Peritonitis of Candida parapsilosis developed later. The infant was successfully treated with hemofiltration and a combination of antifungal agents.

Caspofungin therapy in immunocompromised children and neonates

The prevalence of invasive fungal infections is increasing and the infections are becoming a major problem in immunocompromised children and neonates. Fortunately, there has been a recent surge in the development of new antifungal agents. Caspofungin, the first licensed echinocandin, is a novel class of antifungal and is approved for use in children 3 months of age or older for the treatment of invasive candidiasis, salvage therapy for invasive aspergillosis and as empirical therapy for febrile neutropenia. This article reviews the published data on the use of caspofungin in immunocompromised children and neonates with invasive fungal infections.

Challenging issues in neonatal candidiasis

In an era of quality improvement and 'getting to zero (infections and/or related mortality),' neonatal candidiasis is ripe for evidence-based initiatives. Knowledge of each institution's invasive Candida infection (ICI) incidence and infection-related mortality is critical to evaluate disease burden and effective interventions. Evidenced-based interventions include: antifungal prophylaxis, starting with appropriate dosing, and prompt removal of central venous catheters (CVC). There is A-I evidence supporting antifungal prophylaxis with fluconazole, and it should be considered in every neonatal intensive care unit (NICU). The literature supports targeting infants <1000 g and/or <or=27 weeks, because this group has high infection-related mortality and neurodevelopmental impairment in 57% of survivors. Antifungal prophylaxis has been shown to nearly eliminate infection-related mortality. Interventions start with prenatal initiatives, with women being treated for vaginal candidiasis, especially with preterm labor or complications. Targeting modifiable risk factors, including restriction policies for use of third- and fourth-generation cephalosporins, carbapenems, H2-antagonists, proton pump inhibitors, and postnatal steroids; guidelines for CVC care and removal; and feeding practices, with promotion of early feedings and breast milk, may also reduce risk. A few studies have emerged on empiric antifungal therapy with sepsis evaluations for preterm infants <1500 g and other high-risk patients that have shown favorable effects of eliminating mortality, but these have not been compared to appropriate antifungal therapy and central line removal. Further study of empiric therapy, prospective treatment studies with higher targeted dosing of amphotericin B preparations, fluconazole, and new antifungals with prompt CVC removal may contribute to a 100% survival rate for those infants >1000 g and >or=28 weeks not receiving antifungal prophylaxis. Evaluation of ICI incidence and mortality by gestational age and birth week should be followed in each NICU, to evaluate infection control and prevention.

A Clinical Review of Echinocandins in Pediatric Patients

OBJECTIVE

To identify and evaluate available data on pediatric echinocandin use.

DATA SOURCES

A PubMed search, limited to English-language articles, was conducted (1990-August 2009) using the search terms echinocandin, pediatric, child, pharmacokinetics, caspofungin, micafungin, and anidulafungin. Additional articles were retrieved from citations of selected references.

STUDY SELECTION AND DATA EXTRACTION

Relevant information on the pharmacology, pharmacokinetics, efficacy, and safety of echinocandins in children was selected. Clinical trials, retrospective reviews, and case series were identified and evaluated. Data from these sources were included in this review.

DATA SYNTHESIS

Caspofungin is the only echinocandin approved by the Food and Drug Administration for use in children. Pediatric pharmacokinetics has been evaluated with all 3 echinocandins but is limited with anidulafungin. Micafungin is the most well-studied agent in prospective clinical trials for antifungal prophylaxis in stem cell transplantation and treatment of invasive fungal infections. Caspofungin has been studied prospectively for febrile neutropenia and treatment of invasive fungal infections, but most published data are from retrospective reviews or case reports. One case report of anidulafungin for neonatal candidiasis has been published. The role of echinocandins in the management of invasive pediatric fungal infections has expanded. Micafungin and caspofungin are recommended as primary or alternative treatment of candidemia and esophageal or invasive candidiasis, and as salvage therapy for invasive aspergillosis. Micafungin is recommended for neutropenic prophylaxis in stem cell transplantation, while caspofungin may be used in febrile neutropenia as an alternative to azoles. Dosing has been well established for caspofungin only in children 3 months of age and above. Anidulafungin should be avoided in children until more pharmacokinetic and clinical data become available.

CONCLUSIONS

Further comparative trials are needed to more clearly define the role of echinocandins, either as monotherapy or in combination for difficult-to-treat infections, in the pediatric population.

Pharmacokinetics and safety of caspofungin in neonates and infants less than 3 months of age

Candida infections represent a major threat in neonatal intensive care units. This is the first prospective study to obtain caspofungin plasma levels and safety data for neonates and very young infants. Patients of <3 months of age receiving intravenous amphotericin B for documented or highly suspected candidiasis were enrolled in a single-dose (n = 6) or subsequent multiple-dose (n = 12) panel; all received caspofungin at 25 mg/m(2) once daily as a 1-hour infusion. Caspofungin plasma levels were measured by high-performance liquid chromatography and compared to historical data from adults. Patient chronological ages ranged from 1 to 11 weeks, and weights ranged from 0.68 to 3.8 kg. Gestational ages ranged from 24 to 41 weeks. Geometric mean (GM) peak (C(1 h)) and trough (C(24 h)) caspofungin levels were 8.2 and 1.8 microg/ml, respectively, on day 1, and 11.1 and 2.4 microg/ml, respectively, on day 4. GM ratios for C(1 h) and C(24 h) for neonates/infants relative to adults receiving caspofungin at 50 mg/day were 1.07 and 1.36, respectively, on day 1, and 1.18 and 1.21, respectively, on day 4. Clinical and laboratory adverse events occurred in 17 (94%) and 8 (44%) patients, respectively. Five patients (28%) had serious adverse events, none of which were considered drug related. Caspofungin at 25 mg/m(2) once daily was well tolerated in this group of neonates/infants of <3 months of age and appears to provide relatively similar plasma exposure to that obtained in adults receiving 50 mg/day. However, the small number of patients studied precludes any definitive recommendations about caspofungin dosing for this group comprising a broad range of ages and weights.

Candida parapsilosis, an emerging fungal pathogen

SUMMARY

Candida parapsilosis is an emerging major human pathogen that has dramatically increased in significance and prevalence over the past 2 decades, such that C. parapsilosis is now one of the leading causes of invasive candidal disease. Individuals at the highest risk for severe infection include neonates and patients in intensive care units. C. parapsilosis infections are especially associated with hyperalimentation solutions, prosthetic devices, and indwelling catheters, as well as the nosocomial spread of disease through the hands of health care workers. Factors involved in disease pathogenesis include the secretion of hydrolytic enzymes, adhesion to prosthetics, and biofilm formation. New molecular genetic tools are providing additional and much-needed information regarding C. parapsilosis virulence. The emerging information will provide a deeper understanding of C. parapsilosis pathogenesis and facilitate the development of new therapeutic approaches for treating C. parapsilosis infections.

Antifungal agents in neonates: issues and recommendations

Fungal infections are responsible for considerable morbidity and mortality in the neonatal period, particularly among premature neonates. Four classes of antifungal agents are commonly used in the treatment of fungal infections in pediatric patients: polyene macrolides, fluorinated pyrimidines, triazoles, and echinocandins. Due to the paucity of pediatric data, many recommendations for the use of antifungal agents in this population are derived from the experience in adults. The purpose of this article was to review the published data on fungal infections and antifungal agents, with a focus on neonatal patients, and to provide an overview of the differences in antifungal pharmacology in neonates compared with adults. Pharmacokinetic data suggest dosing differences in children versus adult patients with some antifungals, but not all agents have been fully evaluated. The available pharmacokinetic data on the amphotericin B deoxycholate formulation in neonates exhibit considerable variability; nevertheless, the dosage regimen suggested in the neonatal population is similar to that used in adults. More pharmacokinetic information is available on the liposomal and lipid complex preparations of amphotericin B and fluconazole, and it supports their use in neonates; however, the optimal dosage and duration of therapy is difficult to establish. All amphotericin-B formulations, frequently used in combination with flucytosine, are useful for treating disseminated fungal infections and Candida meningitis in neonates. Fluconazole, with potent in vitro activity against Cryptococcus neoformans and almost all Candida spp., has been used in neonates with invasive candidiasis at dosages of 6 mg/kg/day, and for antifungal prophylaxis in high-risk neonates. There are limited data on itraconazole, voriconazole, and posaconazole use in neonates. Caspofungin, which is active against Candida spp. and Aspergillus spp., requires higher doses in children relative to adults, and dosing is best accomplished based on body surface area. Micafungin shows a clear trend toward lower levels in the smallest patients. There are no data on the use of other new antifungal drugs (ravuconazole and anidulafungin) in neonates. In summary, the initial data suggest dosage differences in neonates for some antifungal agents, although the newer agents have not been fully tested for optimal administration in these patients.

Prevention and treatment of Candida infections in neonates

Invasive Candia infections have become the third most common cause of late-onset infection among very low birth weight infants in most neonatal intensive care units. Significant risk factors include birth weight less than 1000 g, exposure to more than two antibiotics, third generation cephalosporin exposure, parenteral nutrition including lipid emulsion, central venous catheter, and abdominal surgery. The majority of neonatal Candida infections are caused by C. albicans and C. parapsilosis, although other nonalbicans species are being reported more frequently. Standard therapy has been amphotericin B; however, successful use of fluconazole as a single agent has also been reported and a small comparison trial demonstrated similar efficacy. The addition of new antifungal agents, including voriconazole and the echinocandins may further improve our ability to effectively treat these infections and possibly reduce the development of complications. Antifungal chemoprophylaxis has been studied in single-center and cohort studies, primarily using fluconazole. Although it is clear that fluconazole prophylaxis decreases the risk of fungal colonization and infection, identification of potential harm, particularly the development of or selection for resistant strains, requires further investigation with multicenter trials before widespread use is recommended outside of the clinical trial setting.