Neonatal Candida parapsilosis outbreak with a high case fatality rate

Molecular and Epidemiological Investigation of Fluconazole-resistant Candida parapsilosis-Georgia, United States, 2021

Background

Reports of fluconazole-resistant Candida parapsilosis bloodstream infections are increasing. We describe a cluster of fluconazole-resistant C parapsilosis bloodstream infections identified in 2021 on routine surveillance by the Georgia Emerging Infections Program in conjunction with the Centers for Disease Control and Prevention.

Methods

Whole-genome sequencing was used to analyze C parapsilosis bloodstream infections isolates. Epidemiological data were obtained from medical records. A social network analysis was conducted using Georgia Hospital Discharge Data.

Results

Twenty fluconazole-resistant isolates were identified in 2021, representing the largest proportion (34%) of fluconazole-resistant C parapsilosis bloodstream infections identified in Georgia since surveillance began in 2008. All resistant isolates were closely genetically related and contained the Y132F mutation in the ERG11 gene. Patients with fluconazole-resistant isolates were more likely to have resided at long-term acute care hospitals compared with patients with susceptible isolates (P = .01). There was a trend toward increased mechanical ventilation and prior azole use in patients with fluconazole-resistant isolates. Social network analysis revealed that patients with fluconazole-resistant isolates interfaced with a distinct set of healthcare facilities centered around 2 long-term acute care hospitals compared with patients with susceptible isolates.

Conclusions

Whole-genome sequencing results showing that fluconazole-resistant C parapsilosis isolates from Georgia surveillance demonstrated low genetic diversity compared with susceptible isolates and their association with a facility network centered around 2 long-term acute care hospitals suggests clonal spread of fluconazole-resistant C parapsilosis. Further studies are needed to better understand the sudden emergence and transmission of fluconazole-resistant C parapsilosis.

Clinical efficacy and safety of antifungal drugs for the treatment of Candida parapsilosis infections: a systematic review and network meta-analysis

Antifungal drugs have already been established as an effective treatment option for Candida parapsilosis infections, but there is no universal consensus on the ideal target for clinical efficacy and safety of antifungal drugs for the treatment of C. parapsilosis infections. Few studies have directly compared the efficacies of antifungal drugs for the treatment of C. parapsilosis infections. We hypothesize that different antifungal drugs offer differing clinical efficacy and safety for the treatment of C. parapsilosis infections. We performed a comprehensive network meta-analysis on different strategies for C. parapsilosis infection treatment and compared the clinical efficacy and safety of antifungal drugs as interventions for C. parapsilosis infections. The Cochrane Database of Systematic Reviews, Medline, Embase, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), Technology of Chongqing VIP database, Wan Fang Data, and SinoMed databases were searched to identify appropriate randomized trials. Among the extracted C. parapsilosis cases, the survival and death rates with treatment of C. parapsilosis infection were compared among groups treated with different antifungal drugs. According to the evidence-network analysis, echinocandins were a better choice than other drugs for treating C. parapsilosis infections, and more importantly, caspofungin showed a more preferable effect for decreasing the risk of 30 day mortality. In conclusion, this study systematically evaluated the effectiveness and safety of antifungal drugs for the purpose of helping clinicians choose the most appropriate antifungal drugs. Future studies with larger samples are needed to evaluate the effects of patient factors on the clinical efficacy and safety of antifungal drugs for C. parapsilosis infections.

Invasive candidiasis

Invasive candidiasis is an important health-care-associated fungal infection that can be caused by several Candida spp.; the most common species is Candida albicans, but the prevalence of these organisms varies considerably depending on geographical location. The spectrum of disease of invasive candidiasis ranges from minimally symptomatic candidaemia to fulminant sepsis with an associated mortality exceeding 70%. Candida spp. are common commensal organisms in the skin and gut microbiota, and disruptions in the cutaneous and gastrointestinal barriers (for example, owing to gastrointestinal perforation) promote invasive disease. A deeper understanding of specific Candida spp. virulence factors, host immune response and host susceptibility at the genetic level has led to key insights into the development of early intervention strategies and vaccine candidates. The early diagnosis of invasive candidiasis is challenging but key to the effective management, and the development of rapid molecular diagnostics could improve the ability to intervene rapidly and potentially reduce mortality. First-line drugs, including echinocandins and azoles, are effective, but the emergence of antifungal resistance, especially among Candida glabrata, is a matter of concern and underscores the need to administer antifungal medications in a judicious manner, avoiding overuse when possible. A newly described pathogen, Candida auris, is an emerging multidrug-resistant organism that poses a global threat.

Secular Trends of Candidemia in a Large Tertiary-Care Hospital From 1988 to 2000: Emergence ofCandida parapsilosis

Objective:

To analyze the secular trends of candidemia in a large tertiary-care hospital to determine the overall incidence, as well as the incidence by ward and by species, and to detect the occurrence of outbreaks.

Design:

Retrospective descriptive analysis. Secular trends were calculated using the Mantel-Haenszel test.

Setting:

A large tertiary-care referral center in Spain with a pediatric intensive care unit (ICU) to which more than 500 children with congenital cardiac disease are admitted annually.

Patients:

All patients with candidemia occurring from 1988 to 2000 were included. Cases were identified from laboratory records of blood cultures.

Results:

There were 331 episodes of candidemia. The overall incidence of nosocomial candidemia was 0.6 episode per 1,000 admissions and remained stable throughout the study period (P= .925). The species most frequently isolated wasCandida albicans, but the incidence ofC. parapsilosiscandidemia increased (P= .035). In the pediatric ICU, the incidence ofC. parapsilosiswas 5.6 episodes per 1,000 admissions and it was the predominant species. Outbreaks occurred occasionally in the pediatric ICU, suggesting nosocomial transmission.

Conclusions:

During this 13-year period, the incidence of candidemia remained stable in this hospital, butC. parapsilosisincreased in frequency. Occasional outbreaks of candidemia suggested nosocomial transmission ofCandidaspecies (Infect Control Hosp Epidemiol2005;26:548-552).

Advances in the treatment of invasive neonatal candidiasis

INTRODUCTION

Invasive candidiasis is responsible for ∼ 10% of nosocomial sepsis in very-low-birth-weight infants and is associated with substantial morbidity and mortality. Over the last two decades, the antifungal armamentarium against Candida spp. has increased; however, efficacy and safety studies in this population are lacking.

AREAS COVERED

We reviewed the medical literature and extracted information on clinical and observational studies evaluating the use of antifungal agents in neonates with invasive candidiasis.

EXPERT OPINION

Efficacy and safety data for antifungals in neonates are lacking, and the majority of studies conducted to date have concentrated on pharmacokinetic/pharmacodynamic evaluations. Unlike other anti-infective agents, efficacy data in the setting of neonatal candidiasis cannot be extrapolated from adult studies due to differences in the pathophysiology of the disease in this population relative to older children and adults. Data for amphotericin B deoxycholate, fluconazole, and micafungin suggest that these are the current agents of choice for this disease in neonates until data for newer antifungal agents become available. For prophylaxis, data from fluconazole randomized controlled trials will be submitted to the regulatory agencies for labeling. Ultimately, the field of therapeutics for neonatal candidiasis will require multidisciplinary collaboration given the numerous challenges associated with conducting clinical trials in neonates.

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.

Genetic determinants of virulence - Candida parapsilosis

The global epidemiology of fungal infections is changing. While overall, Candida albicans remains the most common pathogen; several institutions in Europe, Asia and South America have reported the rapid emergence to predominance of Candida parapsilosis. This mini-review examines the impact of gene deletions achieved in C. parapsilosis that have been published to date. The molecular approaches to gene disruption in C. parapsilosis and the molecularly characterized genes to date are reviewed. Similar to C. albicans, factors influencing virulence in C. parapsilosis include adherence, biofilm formation, lipid metabolism, and secretion of hydrolytic enzymes such as lipases, phospholipases and secreted aspartyl proteinases. Development of a targeted gene deletion method has enabled the identification of several unique aspects of C. parapsilosis genes that play a role in host-pathogen interactions - CpLIP1, CpLIP2, SAPP1a, SAPP1b, BCR1, RBT1, CpFAS2, OLE1, FIT-2. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).

Safety of fluconazole in paediatrics: a systematic review

PURPOSE

To determine the safety of fluconazole in neonates and other paediatric age groups by identifying adverse events (AEs) and drug interactions associated with treatment.

METHODS

A search of EMBASE (1950-January 2012), MEDLINE (1946-January 2012), the Cochrane database for systematic reviews and the Cumulative Index to Nursing and Allied Health Literature (1982-2012) for any clinical study about fluconazole use that involved at least one paediatric patient (≤17 years) was performed. Only articles with sufficient quality of safety reporting after patients' exposure to fluconazole were included.

RESULTS

We identified 90 articles, reporting on 4,209 patients, which met our inclusion criteria. In total, 794 AEs from 35 studies were recorded, with hepatotoxicity accounting for 378 (47.6 %) of all AEs. When fluconazole was compared with placebo and other antifungals, the relative risk (RR) of hepatotoxicity was not statistically different [RR 1.36, 95 % confidence interval (CI) 0.87-2.14, P = 0.175 and RR 1.43, 95 % CI 0.67-3.03, P = 0.352, respectively]. Complete resolution of hepatoxicity was achieved by 84 % of patients with follow-up available. There was no statistical difference in the risk of gastrointestinal events of fluconazole compared with placebo and other antifungals (RR 0.81, 95 % CI 0.12-5.60, P = 0.831 and RR 1.23, 95 %CI 0.87-1.71, P = 0.235, respectively). There were 41 drug withdrawals, 17 (42 %) of which were due to elevated liver enzymes. Five reports of drug interactions occurred in children.

CONCLUSION

Fluconazole is relatively safe for paediatric patients. Hepatotoxicity and gastrointestinal toxicity are the most common adverse events. It is important to be aware that drug interactions with fluconazole can result in significant toxicity.

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.

Treatment and prophylaxis of invasive candidiasis

Invasive candidiasis (IC) is a leading cause of morbidity and mortality in preterm infants. Even if successfully treated, IC can cause significant neurodevelopmental impairment. Preterm infants are at increased risk for hematogenous Candida meningoencephalitis owing to increased permeability of the blood-brain barrier, so antifungal treatment should have adequate central nervous system penetration. Amphotericin B deoxycholate, lipid preparations of amphotericin B, fluconazole, and micafungin are first-line treatments of IC. Fluconazole prophylaxis reduces the incidence of IC in extremely premature infants, but its safety has not been established for this indication, and as yet, the product has not been shown to reduce mortality in neonates. Targeted prophylaxis may have a role in reducing the burden of disease in this vulnerable population.

Microsatellite multilocus genotyping clarifies the relationship of Candida parapsilosis strains involved in a neonatal intensive care unit outbreak

Microsatellite typing of 25 Candida parapsilosis isolates from a described outbreak in a neonatal intensive care showed 2 large groups of blood isolates that were related to hand isolates from specific hospital staff, not infant-colonizing isolates. These results demonstrate the power of this typing tool in clarifying epidemiologic associations.

Determination of urinary D-/L-arabinitol ratios as a biomarker for invasive candidiasis in children with cardiac diseases

A non-invasive, non-culture-based method of determining urinary D-/L-arabinitol (D-/L-ARA) ratios was investigated as a tool for the diagnosis of invasive candidiasis in nosocomial paediatric infection cases. The study encompassed 138 children aged 4 days to 16 years (mean ± SD=1.6 ± 4.2 years) with congenital heart defects (91.4%) or with rhythm disorders or circulatory failure (8.6%). ARA enantiomers were detected by GC using an electron capture detector. Positive D-/L-ARA ratios were found for 11/11 patients with proven candidiasis and 17/19 patients with clinically suspected invasive candidiasis. Thirty children were undergoing antifungal chemotherapy. D-/L-ARA ratios (mean ± SD) were 2.601 ± 0.544 in hospitalized cardiac patients without fungal infection and 5.120 ± 1.253 in those receiving antifungal therapy (P<0.001). The sensitivity of the method was 100%, the specificity 97.2%, the positive predictive value was 78.6% and the negative predictive value was 100%.

Epidemiology of invasive mycoses in North America

The incidence of invasive mycoses is increasing, especially among patients who are immunocompromised or hospitalized with serious underlying diseases. Such infections may be broken into two broad categories: opportunistic and endemic. The most important agents of the opportunistic mycoses are Candida spp., Cryptococcus neoformans, Pneumocystis jirovecii, and Aspergillus spp. (although the list of potential pathogens is ever expanding); while the most commonly encountered endemic mycoses are due to Histoplasma capsulatum, Coccidioides immitis/posadasii, and Blastomyces dermatitidis. This review discusses the epidemiologic profiles of these invasive mycoses in North America, as well as risk factors for infection, and the pathogens' antifungal susceptibility.

Number of sites of perinatal Candida colonization and neutropenia are associated with nosocomial candidemia in the neonatal intensive care unit patient

OBJECTIVES

To determine the role of perinatally acquired Candida colonization to invasive Candida infection (candidemia) and to assess risk factors associated with Candida colonization and candidemia in neonatal intensive care unit patients.

DESIGN

Retrospective case-control study.

SETTING

Neonatal intensive care unit of a teaching hospital.

PATIENTS

A total of 39 of 3219 (1.2%) who were positive for Candida colonization at birth were compared with 117 noncolonized controls.

INTERVENTIONS

Routine surveillance cultures for Candida of skin and meconium were performed at admission. All neonates with Candida colonization at birth during a 10-yr period were identified. Each case was matched to place of birth and date of admission with three noncolonized controls.

MEASUREMENTS AND MAIN RESULTS

Perinatal and neonatal variables were collected. Blood or skin culture was obtained when signs of sepsis or dermatitis were present. Patients with Candida colonization were compared with their noncolonized controls, whereas in this cohort, patients with candidemia were compared with those without by multivariate analysis. Vaginal candidiasis (odds ratio [OR] 15.8, 95% confidence interval [CI] 2.63, 94.77), birth weight below 1000 g (OR 8.1, 95% CI 1.22, 52.26), and vaginal delivery (OR 7.08, 95% CI 1.17, 42.70) were associated with Candida colonization. An increased risk for nosocomial candidemia was independently associated with the number of sites of Candida colonization (OR 24.02, 95% CI 1.89, 304), early neonatal neutropenia (OR 7.15, 95% CI 0.98, 80.95) and illness severity (clinical risk index for babies [CRIB]) score at day 1 (OR 1.38, 95%CI 1.065, 1.811).

CONCLUSIONS

Maternal vaginal candidiasis and vaginal birth are risk factors for neonatal colonization. When controlling for illness severity, the number of sites colonized with Candida at birth contributes to neonatal nosocomial candidemia. Early neutropenia increases the risk further. These findings offer opportunities for prevention of Candida infection in neonatal intensive care unit patients.

Candida parapsilosis: a review of its epidemiology, pathogenesis, clinical aspects, typing and antimicrobial susceptibility

The Candida parapsilosis family has emerged as a major opportunistic and nosocomial pathogen. It causes multifaceted pathology in immuno-compromised and normal hosts, notably low birth weight neonates. Its emergence may relate to an ability to colonize the skin, proliferate in glucose-containing solutions, and adhere to plastic. When clusters appear, determination of genetic relatedness among strains and identification of a common source are important. Its virulence appears associated with a capacity to produce biofilm and production of phospholipase and aspartyl protease. Further investigations of the host-pathogen interactions are needed. This review summarizes basic science, clinical and experimental information about C. parapsilosis.

Micafungin: a review of its use in the prophylaxis and treatment of invasive Candida infections in pediatric patients

Intravenous micafungin (Mycamine; Funguard) is an echinocandin indicated in Japan and the EU for the treatment of pediatric patients (including neonates) with invasive candidiasis and as prophylaxis against Candida infection in pediatric patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). In the EU, micafungin is also indicated in pediatric patients who are expected to have neutropenia for >/=10 days. In Japan, children may also receive micafungin for the treatment of, or as prophylaxis against, invasive Aspergillus infection. Micafungin is not currently approved for use in pediatric patients in the US. Micafungin has very good antifungal activity against a wide range of Candida spp. in vitro. It has a favorable pharmacokinetic profile allowing for once-daily administration, has few drug-drug interactions, and reports of resistance are rare. The results of pediatric substudies indicate that intravenous micafungin is effective in a majority of patients for the treatment of candidemia and other types of invasive candidiasis, and provides effective prophylaxis against invasive fungal infections in pediatric patients undergoing HSCT. The tolerability profile of micafungin in pediatric patients was generally acceptable. In the EU, micafungin is indicated for use when other antifungal medications are not appropriate. Therefore, micafungin provides an alternative to other antifungal agents used in the management of candidemia and invasive candidiasis in pediatric patients, or as prophylaxis against fungal infections in pediatric patients undergoing HSCT.

Influence of sodium intake on Amphotericin B-induced nephrotoxicity among extremely premature infants

Amphotericin B (AmphoB) remains the preferred therapy for invasive fungal infections despite many side effects, such as nephrotoxicity and electrolyte imbalance. Our previous study suggested that high sodium (Na) intake >4 mEq/kg per day may be associated with lower nephrotoxicity in extremely premature infants treated with AmphoB. Subsequently, it became a standard of care in our unit to administer Na >4 mEq/kg per day to extremely premature infants treated with AmphoB. The purpose of this study was to evaluate the effect of high Na intake > 4 mEq/kg per day on the incidence of AmphoB-induced nephrotoxicity among extremely premature infants with birth weight <1250 gm. All extremely premature infants with birth weight <1250 gm born between 1992 and 2004 and treated with AmphoB for systemic fungal infections were included in the study. The study infants were divided into two groups: a control (CL) group (1/1992-12/1999, n = 21) consisting of extremely premature infants given a maintenance Na intake during AmphoB therapy, and a high sodium intake (High Na) group (1/2000-12/2004, n = 16) consisting of extremely premature infants given a high Na intake >4 mEq/kg per day during AmphoB therapy. Nephrotoxicity was defined as serum creatinine levels >1 mg/dl, urinary output (UOP) < 1 ml/kg per hour or a decrease in UOP of 50%, compared with the previous 2 days, and persisting for at least 2 days. Invasive fungal infection was diagnosed in 5.7% of the infants (44/763 infants). Thirty-seven infants were eligible for the study and seven were excluded. There were no differences between the two groups in gestational age, birth weight, age at fungal infection diagnosis, length of AmphoB therapy, daily fluid intake or hyponatremia. Nephrotoxicity was significantly higher in the CL group than in the High Na group (13/21 vs. 3/16; P = 0.02). In the CL group, nephrotoxicity occurred at (mean +/- SD) 1.9 +/- 3.2 days after the initiation of AmphoB treatment and lasted for 5.5 +/- 4.7 days. In this group, nephrotoxicity occurred in two of the 13 infants before the initiation of AmphoB therapy. In the High Na group, nephrotoxicity occurred before the start of AmphoB therapy in two of the three infants. In the third infant, nephrotoxicity lasted for 1 day. Mean Na intake was not different between the two groups during the 4-day period prior to AmphoB therapy. Mean Na intake during the first 10-day period of AmphoB therapy was significantly lower in the CL group (3.7 vs 6.2; P < 0.001).

CONCLUSION

High Na intake was associated with a reduction in the incidence of AmphoB-induced nephrotoxicity in extremely premature infants with birth weight <1250 gm. We recommend the use of a high Na intake of >4 mEq/kg per day for extremely premature infants during Amphotericin B therapy.

Correlation between biofilm formation and the hypoxic response in Candida parapsilosis

The ability of Candida parapsilosis to form biofilms on indwelling medical devices is correlated with virulence. To identify genes that are important for biofilm formation, we used arrays representing approximately 4,000 open reading frames (ORFs) to compare the transcriptional profile of biofilm cells growing in a microfermentor under continuous flow conditions with that of cells in planktonic culture. The expression of genes involved in fatty acid and ergosterol metabolism and in glycolysis, is upregulated in biofilms. The transcriptional profile of C. parapsilosis biofilm cells resembles that of Candida albicans cells grown under hypoxic conditions. We therefore subsequently used whole-genome arrays (representing 5,900 ORFs) to determine the hypoxic response of C. parapsilosis and showed that the levels of expression of genes involved in the ergosterol and glycolytic pathways, together with several cell wall genes, are increased. Our results indicate that there is substantial overlap between the hypoxic responses of C. parapsilosis and C. albicans and that this may be important for biofilm development. Knocking out an ortholog of the cell wall gene RBT1, whose expression is induced both in biofilms and under conditions of hypoxia in C. parapsilosis, reduces biofilm development.

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.

Epidemiology and clinical outcome of candidaemia among Jordanian newborns over a 10-year period

This retrospective study includes all newborn patients with culture proved candidaemia who were admitted to the neonatal intensive care unit of Jordan University Hospital through the period January 1995 to June 2006. Among 24 patients included, 13 (54.2%) died. The incidence of candidaemia was 0.27%, the mean age at diagnosis 25.9 d and the mean gestational age at birth 34.6 weeks. Species most frequently isolated were Candida albicans (50%) and C. krusei (20%). Previous gastrointestinal pathology was present in 41.7% of the cases. A comparison of cases due to C. albicans with those due to other species of Candida revealed no statistical differences in terms of demographic factors, age at onset of disease, mortality, clinical manifestations or risk factors. Based on our results, empirical antifungal therapy should be considered in neonates who have gastrointestinal pathology and other risk factors.

Geographic and temporal trends in isolation and antifungal susceptibility of Candida parapsilosis: a global assessment from the ARTEMIS DISK Antifungal Surveillance Program, 2001 to 2005

We examined data from the ARTEMIS DISK Antifungal Surveillance Program to describe geographic and temporal trends in the isolation of Candida parapsilosis from clinical specimens and the in vitro susceptibilities of 9,371 isolates to fluconazole and voriconazole. We also report the in vitro susceptibility of bloodstream infection (BSI) isolates of C. parapsilosis to the echinocandins, anidulafungin, caspofungin, and micafungin. C. parapsilosis represented 6.6% of the 141,383 isolates of Candida collected from 2001 to 2005 and was most common among isolates from North America (14.3%) and Latin America (9.9%). High levels of susceptibility to both fluconazole (90.8 to 95.8%) and voriconazole (95.3 to 98.1%) were observed in all geographic regions with the exception of the Africa and Middle East region (79.3 and 85.8% susceptible to fluconazole and voriconazole, respectively). C. parapsilosis was most often isolated from blood and skin and/or soft tissue specimens and from patients hospitalized in the medical, surgical, intensive care unit (ICU) and dermatology services. Notably, isolates from the surgical ICU were the least susceptible to fluconazole (86.3%). There was no evidence of increasing azole resistance over time among C. parapsilosis isolates tested from 2001 to 2005. Of BSI isolates tested against the three echinocandins, 92, 99, and 100% were inhibited by concentrations of < or = 2 microg/ml of anidulafungin (621 isolates tested), caspofungin (1,447 isolates tested), and micafungin (539 isolates tested), respectively. C. parapsilosis is a ubiquitous pathogen that remains susceptible to the azoles and echinocandins; however, both the frequency of isolation and the resistance of C. parapsilosis to fluconazole and voriconazole may vary by geographic region and clinical service.

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.

Candida parapsilosis fungemia in neonates: genotyping results suggest healthcare workers hands as source, and review of published studies

An outbreak of Candida parapsilosis fungemia involving 17 neonatal intensive care unit (NICU) patients was studied. There were 14 blood culture and nine colonizing isolates from other sites available. The hands of NICU healthcare workers (HCW) yielded eight isolates. Screening of the isolates by random amplified polymorphic DNA (RAPD) method showed only three profiles. Typing by restriction fragment length polymorphism (RFLP) revealed all blood isolates were RFLP subtype VII-1. Among the nine infant colonizing isolates, there were four different RFLP subtypes; four of the isolates were subtype VII-1. Seven of the eight isolates from HCW were RFLP subtype VII-1. The majority of infant colonizers were not found in the blood, suggesting a possible direct spread of the epidemic subtype VII-1 strain from HCW hands to infant blood. The source of the infant colonizing strains is unclear, but non-VII-1 strains may be largely of maternal origin and VII-1 strains from HCW. These findings reinforce prior studies that have implicated HCW hands as the source of nosocomial, including neonatal, fungemia.

Development of a gene knockout system in Candida parapsilosis reveals a conserved role for BCR1 in biofilm formation

Candida parapsilosis is an important cause of candidiasis, yet few molecular tools are available. We adapted a recyclable nourseothricin resistance marker gene (SAT1) originally developed for use with C. albicans in order to generate gene knockouts from C. parapsilosis. We first replaced the promoters driving expression of the FLP recombinase and the SAT1 genes with the equivalent sequences from C. parapsilosis. We then used the cassette to generate a homozygous knockout of C. parapsilosis URA3. The ura3 knockouts have altered colony morphologies. We also knocked out both alleles of an ortholog of BCR1, a gene encoding a transcription factor known to be required for biofilm development in C. albicans. We show that C. parapsilosis BCR1 is necessary for biofilm development in C. parapsilosis and for expression of the cell wall protein encoded by RBT1. Our results suggest that there are significant similarities in the regulation of biofilms between the two species, despite the fact that C. parapsilosis does not generate true hyphae and that BCR1 regulates the expression of many hypha-specific adhesins in C. albicans.

Epidemiology of invasive candidiasis: a persistent public health problem

Invasive candidiasis (IC) is a leading cause of mycosis-associated mortality in the United States. We examined data from the National Center for Health Statistics and reviewed recent literature in order to update the epidemiology of IC. IC-associated mortality has remained stable, at approximately 0.4 deaths per 100,000 population, since 1997, while mortality associated with invasive aspergillosis has continued to decline. Candida albicans remains the predominant cause of IC, accounting for over half of all cases, but Candida glabrata has emerged as the second most common cause of IC in the United States, and several less common Candida species may be emerging, some of which can exhibit resistance to triazoles and/or amphotericin B. Crude and attributable rates of mortality due to IC remain unacceptably high and unchanged for the past 2 decades. Nonpharmacologic preventive strategies should be emphasized, including hand hygiene; appropriate use, placement, and care of central venous catheters; and prudent use of antimicrobial therapy. Given that delays in appropriate antifungal therapy are associated with increased mortality, improved use of early empirical, preemptive, and prophylactic therapies should also help reduce IC-associated mortality. Several studies have now identified important variables that can be used to predict risk of IC and to help guide preventive strategies such as antifungal prophylaxis and early empirical therapy. However, improved non-culture-based diagnostics are needed to expand the potential for preemptive (or early directed) therapy. Further research to improve diagnostic, preventive, and therapeutic strategies is necessary to reduce the considerable morbidity and mortality associated with IC.

Antifungal resistance in Candida spp. isolated in Italy between 2002 and 2005 from children and adults

The activity of amphotericin B, fluconazole, flucytosine, itraconazole and voriconazole was tested in vitro against 618 clinical Candida spp. isolates, using the broth microdilution or the disk diffusion method (voriconazole). Amphotericin B and voriconazole were the most potent antifungal agents assayed (100% of susceptible strains). Resistance to fluconazole and itraconazole was detected in three (0.7%) and 11 (2.7%) isolates of Candida albicans and in four (3.7%) isolates of Candida glabrata. Flucytosine intermediate, resistant strains, or both, were observed in C. albicans (0.3% and 0.7%), C. glabrata (2.8% intermediate) and C. tropicalis (15.2% and 15.2%). C. krusei was the least susceptible species to azoles. No statistically significant differences in the rates of resistant isolates depending on site of infection and age of the patient were observed, with the exception of C. albicans and itraconazole (higher percentage of resistance in children). At present, acquired antifungal resistance represents an uncommon finding in most Candida spp. circulating in Northern Italy.

Inhibition of fungal beta-1,3-glucan synthase and cell growth by HM-1 killer toxin single-chain anti-idiotypic antibodies

Single-chain variable-fragment (scFv) anti-idiotypic antibodies of an HM-1 killer toxin (HM-1) from the yeast Williopsis saturnus var. mrakii IFO 0895 have been produced by recombinant DNA technology from the splenic lymphocytes of mice immunized by idiotypic vaccination with a neutralizing monoclonal antibody (nMAb-KT). The fungicidal activity of scFv anti-idiotypic antibodies against the isolates of four Candida species was assessed by MIC analysis. scFv antibodies were fungicidal at concentrations of 1.56 to 12.5 microg/ml in vitro against four Candida species. The scFv antibodies exerted a strong candidacidal activity in vitro, with 50% inhibitory concentration (IC(50)) values ranging from 7.3 x 10(-8) to 16.0 x 10(-8) M, and were neutralized by adsorption with nMAb-KT. Furthermore, all scFv antibodies effectively inhibited fungal beta-1,3-glucan synthase activity in vitro, with IC(50) values ranging from 2.0 x 10(-8) to 22.7 x 10(-8) M, values which almost coincide with the values that are inhibitory to the growth of fungal cells. Binding assays showed that the scFv antibodies specifically bind to nMAb-KT, and this binding pattern was confirmed by surface plasmon resonance analysis. The binding ability was further demonstrated by the competition observed between scFv antibodies and HM-1 to bind nMAb-KT. To the best of our knowledge, this is the first study to show that an antifungal anti-idiotypic antibody, in the form of recombinant scFv, potentially inhibits beta-1,3-glucan synthase activity.

Oral nystatin prophylaxis to prevent invasive candidiasis in Neonatal Intensive Care Unit

The use of oral nystatin to prevent fungal colonisation and infection in neonates in the Neonatal Intensive Care Unit (NICU) is still an open question and not yet recommended as a standard of care. To determine whether prophylactic oral nystatin results in a decreased incidence of invasive candidiasis in the newborn infants, a total of 3991 infants were divided randomly into two groups. Group A infants (n = 1995), only those neonates who were identified as yeast carriers (oral moniliasis) were treated with oral nystatin. Group B infants, all neonates who were admitted to the unit received oral nystatin, was routinely administered three times a day. Group A was divided into groups A1 and A2 (who were treated only if identified as yeast carriers). Urine and rectal cultures were taken on admission and then weekly thereafter. There were 215 (14.2%), 27 (5.6%) and 36 (1.8%) patients positive for invasive candidiasis in groups A1, A2 and B respectively. Oral nystatin prophylaxis significantly reduced the invasive candidiasis (P = 0.004) in extremely low-birth weight (ELBW) and very low-birth weight (VLBW) infants. Prophylactic administration of oral nystatine to the ELBW and VLBW infants results in a decreased risk of invasive candidiasis.

Invasive Candidiasis

Invasive candidiasis remains an important nosocomial infection that continues to present major diagnostic and therapeutic challenges to the clinician. Changes in the epidemiology of this disorder have occurred for many reasons, and included especially the extensive use of prophylactic antifungal agents, broad-spectrum antibacterial agents, and medical devices (eg, chronic indwelling intravascular catheters). The diagnosis of IC remains elusive in many patients, and there is a critical need for improved diagnostics that will provide clinicians the opportunity to intervene earlier in the course of disease. Newer antifungal agents offer promise in the treatment of candidemia and other forms of IC, but the optimal use of these agents, particularly in the approach to non-albicans Candida infections, needs to be explored in more detail. Furthermore, despite an overwhelming amount of data concerning risk factors and excess mortality associated with the development of IC, there is no consistent approach to treatment and primary prevention among individuals who are deemed to be at highest risk for this complication. Research that focuses on these important clinical areas could provide valuable insights into the diagnosis and management of this common and evolving infection.

Candidemia in pediatric patients with congenital heart disease

Candidemia is an important problem in pediatrics. In our hospital, highest candidemia rates were documented among children with congenital heart disease (CHD). A series was conducted to describe the clinical and mortality features of candidemia in these patients. Fifty-two cases (1988-2000) included very young infants (median age, 2 months) who received long-term antibiotic treatment (median, 20.5 days). Candida parapsilosis predominated (54%). Endovascular infections occurred in 11.5%. In-hospital mortality was 39% and related mortality 14%. Maintenance of catheter (odds ratio [OR], 6.0; 95% confidence interval [CI], 1.0-37.2; P = .05) and severity of patients as measured with the Pediatric Risk Score of Mortality I (OR, 1.1, 95% CI, 1.0-1.3; P = .05) were independently associated with mortality. In summary, candidemia in children with CHD is diagnosed to very young infants with prolonged antibiotic therapy. Mortality is high but, in most cases, is not related to candidemia. Optimal management may include exclusion of endocarditis, early antifungal treatment, and catheter removal.

Invasive fungal infections caused by Candida and Malassezia species in the neonatal intensive care unit

Premature infants in the neonatal intensive care unit (NICU) are at particular risk of invasive fungal infections, and unfortunately, the incidence of fungal septicemia appears to be increasing. Invasive infections caused by species of Candida or Malassezia have been documented in the NICU and are often associated with significant morbidity and mortality. Controversies regarding the diagnosis, treatment, and prevention of such diseases exist. The purpose of this review is to describe the epidemiology, clinical manifestations, diagnostic techniques, treatment, and prevention of invasive infection due to Candida and Malassezia species in the neonatal intensive care setting.

Population pharmacokinetics of amphotericin B lipid complex in neonates

The pharmacokinetics of amphotericin B lipid complex (ABLC) were investigated in neonates with invasive candidiasis enrolled in a phase II multicenter trial. Sparse blood (153 samples; 1 to 9 per patient, 1 to 254 h after the dose) and random urine and cerebrospinal fluid (CSF) samples of 28 neonates (median weight [WT], 1.06 kg; range, 0.48 to 4.9 kg; median gestational age, 27 weeks; range, 24 to 41 weeks) were analyzed. Patients received intravenous ABLC at 2.5 (n = 15) or 5 (n = 13) mg/kg of body weight once a day over 1 or 2 h, respectively, for a median of 21 days (range, 4 to 47 days). Concentrations of amphotericin B were quantified as total drug by high-performance liquid chromatography. Blood data for time after dose (TAD) of <24 h fitted best to a one-compartment model with an additive-error model for residual variability, WT0.75 (where 0.75 is an exponent) as a covariate of clearance (CL), and WT as a covariate of volume of distribution (V). Prior amphotericin B, postnatal age, and gestational age did not further improve the model. The final model equations were CL (liters/h) = 0.399 x WT(0.75) (interindividual variability, 35%) and V (liters) = 10.5 x WT (interindividual variability, 43%). Noncompartmental analysis of pooled data with a TAD of >24 h revealed a terminal half-life of 395 h. Mean concentrations in the urine after 1, 2, and 3 weeks ranged from 0.082 to 0.430 microg/ml, and those in CSF ranged from undetectable to 0.074 microg/ml. The disposition of ABLC in neonates was similar to that observed in other age groups: weight was the only factor that influenced clearance. Based on these results and previously published safety and efficacy data, we recommend a daily dosage between 2.5 and 5.0 mg/kg for treatment of invasive Candida infections in neonates.

Candidemia in neonatal intensive care units: Barcelona, Spain

BACKGROUND

Candida spp. are increasingly important hospital-acquired pathogens in neonatal intensive care units (NICU) and cause considerable mortality in preterm infants. Most studies have been limited to a single institution. The aim of this study was to determine the epidemiology of candidemia in all Barcelona NICUs.

METHODS

We conducted prospective population-based surveillance for candidemia in Barcelona, Spain, during 2002-2003. This report focuses on the results from 5 participating hospitals with NICUs.

RESULTS

We detected 24 cases, resulting in an annual incidence of 32.6 cases per 100,000 live births and 1.1 cases per 100 NICU discharges. Median gestational age was 27.5 weeks (range, 24-40.5), and there were 21 cases among very low birth weight infants. Among the 20 (83%) cases evaluated for the presence of end organ infection, endophthalmitis occurred in 2 cases, and endocarditis, meningitis and peritonitis occurred in 1 case each. Candida parapsilosis was the most frequent species isolated (67%). All isolates were fluconazole-susceptible. Crude mortality was 21%.

CONCLUSIONS

The preponderance of C. parapsilosis candidemias observed in Barcelona NICUs is similar to reports from the literature. Morbidity and mortality associated with neonatal candidemia remain high.

Emergence of fluconazole resistance in a Candida parapsilosis strain that caused infections in a neonatal intensive care unit

Candida parapsilosis is an increasing cause of bloodstream infections (BSIs) in neonatal intensive care units (NICUs). It has been a persistent problem in the NICU of Hospital for Children and Adolescents, Helsinki University Central Hospital, Helsinki, Finland, since 1987. Fluconazole prophylaxis has been used to control the problem. The number of new infections has, however, increased markedly since September 2000. We assessed fluconazole consumption and occurrence of all Candida species in the NICU from 1991 to 2002. C. parapsilosis bloodstream isolates obtained in the NICU from 1990 to 2002 (n = 26) were genotyped and their fluconazole susceptibility was defined. A low rate of C. parapsilosis BSIs was correlated with high rates of consumption of fluconazole. No emergence of Candida species with primary resistance to fluconazole was detected. However, genotyping with a complex DNA fingerprinting probe revealed that a single strain of C. parapsilosis with decreasing susceptibility to fluconazole was responsible for cross-infections that caused BSIs in the NICU over a 12-year period. The emergence of fluconazole resistance in that strain was observed after more than 10 years of fluconazole prophylaxis.

Twice weekly fluconazole prophylaxis for prevention of invasive Candida infection in high-risk infants of <1000 grams birth weight

OBJECTIVES

We tested the hypothesis that twice weekly prophylactic dosing of fluconazole prevents invasive candidiasis without promoting resistant Candida species in high-risk, preterm infants.

STUDY DESIGN

We compared our previous dosing schedule (Group A) to a less frequent dosing schedule of twice a week (Group B) of fluconazole prophylaxis for up to 6 weeks in a prospective, randomized, double-blind clinical trial in preterm infants weighing <1000 grams at birth and with an endotracheal tube and/or central vascular catheter over a 24-month period. Weekly surveillance cultures were obtained on study patients.

RESULTS

Candida colonization was documented in 5 (12%) of 41 Group A and in 4 (10%) of 40 Group B infants. Candida sepsis developed in two (5%) of Group A and one (3%) of Group B infants (risk difference, -0.02; 95% confidence interval, -0.14-0.10; P=.68). All fungal isolates remained sensitive to fluconazole, and no drug side effects were documented.

CONCLUSIONS

Twice weekly dosing of prophylactic fluconazole can decrease Candida colonization and invasive infection, cost, and patient exposure in high-risk, preterm infants weighing <1000 grams at birth. We speculate that lower and less frequent dosing may delay or prevent the emergence of antifungal resistance.

Antifungal susceptibility of Candida spp. isolated from pediatric patients: A survey of 4 children's hospitals

Candida species are the most common cause of fungal infections in hospitalized patients. Recent studies have reported a relative reduction in the rates of infection caused by Candida albicans and a shift toward non-albicans Candida spp. Data on the distribution and susceptibility of Candida spp. from children's hospitals are limited. Clinical isolates of Candida were collected from 4 US children's hospitals in 2003. Broth dilution MICs for amphotericin B, fluconazole, voriconazole, caspofungin, posaconazole, and ravuconazole were performed according to National Committee for Clinical Laboratory Standards-approved methodology. A total of 179 clinical isolates were identified and included. Of 179, 77 (43%) were C. albicans. Candida parapsilosis isolates were the second most frequently identified (57/175, 32%), followed by Candida glabrata, Candida tropicalis, and Candida lusitaniae (approximately 8% each). Caspofungin was the most active agent in vitro against all Candida spp. Fluconazole resistance was seen among C. glabrata, C. tropicalis, and Candida krusei isolates. Newer azoles had improved activity against fluconazole-resistant isolates of Candida. Among isolates of C. parapsilosis, nearly 20% were resistant to amphotericin B. The current study highlights the emergence of C. parapsilosis as a distinct pediatric pathogen with clinical and therapeutic implications. Furthermore, our current susceptibility data include newer antifungal agents that appear to be quite active in vitro and may provide new therapeutic options for the treatment of serious yeast infections in children.

Risk factors for Candida infections in a neonatal intensive care unit in Costa Rica

OBJECTIVE

To identify potential risk factors associated with Candida infections and compare these risk factors between patients who both died and survived.

STUDY DESIGN

A group of patients with positive Candida spp. blood cultures admitted to a neonatal intensive care unit (NICU) in Costa Rica between January 1994 and December 1998. Cases were identified through a computerized search of the microbiology laboratory's database on blood cultures.

RESULTS

One hundred and ten newborns were identified. Sixty-six patients (60%) were male; 46 (62%) were preterm infants. Thirty-seven (34%) patients died. Twenty (54%) of them died within three days of the candidemia diagnosis and 17 had disseminated Candida infection on autopsy. Candida albicans and Candida tropicalis were isolated in 90% and 10% of blood cultures, respectively. Mean +/- SD (range) number of days from admission to NICU to the initial positive blood culture were 13.5 +/- 8.5 (1-30) days. Most patients had at least two positive blood cultures (range 1-8). Median (range) days for the sterilization of blood culture were four (1-25) days. Significant differences in survival were identified in patients with axillary-inguinal lesions, apnea and seizures.

CONCLUSIONS

Invasive fungal infections are frequent in NICU. Future case-control prospective studies should be carried out to confirm the findings from this report.

Neonatal candidiasis: analysis of epidemiology, drug susceptibility, and molecular typing of causative isolates

A prospective observational study of invasive candidiasis was conducted in the neonatal intensive care unit of Aristotle University in Hippokration Hospital between 1994 and 2000. During this period, 59 neonates developed invasive candidiasis (58 cases of candidemia and 1 case of peritonitis), resulting in an overall incidence of 1.28% that showed a decreasing trend over the study period. Eleven (18.6%) cases developed within the first week of life and the others within a mean (+/-SEM) of 13.4+/-1.7 days after birth. The three most frequent causative species were Candida albicans (65.5%), Candida parapsilosis (15.5%), and Candida tropicalis (7%). C. albicans was the predominant species between 1994 and 1998, whereas, non-albicans Candida spp., particularly C. parapsilosis, were the most frequent species during the period 1999-2000 (P<0.001). While the overall mortality due to candidemia was 29% (17 of 59 cases), mortality associated with C. albicans and C. parapsilosis was 39.5% and 11.1%, respectively (P=0.032), and that observed in the 1999-2000 period was 0% (P=0.011). Virtually all isolates were susceptible to amphotericin B, flucytosine, fluconazole, and itraconazole, and no increases in minimal inhibitory concentrations were observed during these years. With the exception of a limited cluster of cases due to genotypically identical isolates, no clonal relation of C. albicans isolates was found. Moreover, no clonal persistence of C. albicans and no decrease in antifungal drug susceptibility occurred over the 6-year study period. Non-albicans Candida spp., mostly C. parapsilosis, have emerged as important pathogens in neonatal intensive care units, with infected patients having better outcomes as compared to patients infected with C. albicans.

Epidemiologic background of hand hygiene and evaluation of the most important agents for scrubs and rubs

The etiology of nosocomial infections, the frequency of contaminated hands with the different nosocomial pathogens, and the role of health care workers' hands during outbreaks suggest that a hand hygiene preparation should at least have activity against bacteria, yeasts, and coated viruses. The importance of efficacy in choosing the right hand hygiene product is reflected in the new Centers for Disease Control and Prevention guideline on hand hygiene (J. M. Boyce and D. Pittet, Morb. Mortal. Wkly. Rep. 51:1-45, 2002). The best antimicrobial efficacy can be achieved with ethanol (60 to 85%), isopropanol (60 to 80%), and n-propanol (60 to 80%). The activity is broad and immediate. Ethanol at high concentrations (e.g., 95%) is the most effective treatment against naked viruses, whereas n-propanol seems to be more effective against the resident bacterial flora. The combination of alcohols may have a synergistic effect. The antimicrobial efficacy of chlorhexidine (2 to 4%) and triclosan (1 to 2%) is both lower and slower. Additionally, both agents have a risk of bacterial resistance, which is higher for chlorhexidine than triclosan. Their activity is often supported by the mechanical removal of pathogens during hand washing. Taking the antimicrobial efficacy and the mechanical removal together, they are still less effective than the alcohols. Plain soap and water has the lowest efficacy of all. In the new Centers for Disease Control and Prevention guideline, promotion of alcohol-based hand rubs containing various emollients instead of irritating soaps and detergents is one strategy to reduce skin damage, dryness, and irritation. Irritant contact dermatitis is highest with preparations containing 4% chlorhexidine gluconate, less frequent with nonantimicrobial soaps and preparations containing lower concentrations of chlorhexidine gluconate, and lowest with well-formulated alcohol-based hand rubs containing emollients and other skin conditioners. Too few published data from comparative trials are available to reliably rank triclosan. Personnel should be reminded that it is neither necessary nor recommended to routinely wash hands after each application of an alcohol-based hand rub. Long-lasting improvement of compliance with hand hygiene protocols can be successful if an effective and accessible alcohol-based hand rub with a proven dermal tolerance and an excellent user acceptability is supplied, accompanied by education of health care workers and promotion of the use of the product.

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.

Effects of fluid and electrolyte management on amphotericin B-induced nephrotoxicity among extremely low birth weight infants

OBJECTIVE

Greater use of invasive procedures and aggressive antimicrobial therapy predispose extremely low birth weight (ELBW) infants to systemic fungal sepsis. Despite its adverse effects (including renal and electrolyte disturbances), amphotericin B (amphoB) remains the preferred drug for fungal therapy. Multiple studies have indicated that sodium loading may prevent renal toxicity among animals and human adults. The effects of fluid and electrolyte management on amphoB-induced nephrotoxicity among ELBW infants have not been evaluated extensively. The purpose of this study was to examine the effects of fluid and electrolyte management on amphoB-induced nephrotoxicity among ELBW infants.

DESIGN/METHODS

The medical records were reviewed for all ELBW infants (birth weights of < or =1250 g) who developed systemic fungal sepsis, requiring amphoB therapy, between January 1992 and December 2000. Demographic, clinical, and laboratory data were collected from the medical records for each patient.

RESULTS

Fungal sepsis requiring amphoB treatment developed for 4.4% of ELBW infants (25 of 573 infants), with a gestational age of 25 +/- 1 weeks and a birth weight of 738 +/- 37 g, at a postnatal age of 16 +/- 2 days. Renal compromise, as manifested by low urine output and high creatinine levels, occurred for 44% of those infants (11 of 25 infants). There was no difference between the infants who developed renal compromise (renal compromise group [RCG], n = 11) and those who did not (no-renal-compromise group [NCG], n = 14) with respect to birth weight, gestational age, and risk factors predisposing the infants to fungal sepsis. The RCG demonstrated a decrease in urine output by 3.4 +/- 2 days and an increase in serum creatinine levels by 3.9 +/- 2 days after the initiation of amphoB therapy. Infants in the RCG had a significantly higher incidence of hyponatremia, compared with infants in the NCG (7 of 11 infants vs 0 of 14 infants), with no significant difference in the incidences of hypokalemia (2 of 11 infants vs 0 of 14 infants). Infants in the RCG, compared with infants in the NCG, had significantly lower mean daily sodium intakes in the 4 days before the initiation of amphoB therapy (2.6-2.9 mEq/kg per day vs 4.2-4.7 mEq/kg per day) and in the first 4 days of amphoB treatment (2.7-3.1 mEq/kg per day vs 4.5-5.6 mEq/kg per day). Mean daily sodium intakes were not statistically significantly different between the 2 groups between day 5 and day 10 of amphoB therapy. Infants in the RCG tended to have lower mean daily potassium intakes in the 4 days before the initiation of amphoB therapy and during the first 4 days of amphoB therapy. Subsequently, the mean daily potassium intakes remained not statistically significantly different between the groups. Mean daily fluid intakes were not different between the groups.

CONCLUSIONS

Conventional amphoB combined with adequate hydration and higher sodium intakes of >4 mEq/kg per day may provide effective protection against amphoB-induced nephrotoxicity among ELBW infants. Our data confirm the published results of animal and human adult studies and suggest that higher sodium intakes may prevent renal compromise during amphoB therapy among ELBW infants.

Candida tropicalis in a neonatal intensive care unit: epidemiologic and molecular analysis of an outbreak of infection with an uncommon neonatal pathogen

From June to July 1998, two episodes of Candida tropicalis fungemia occurred in the Aristotle University neonatal intensive care unit (ICU). To investigate this uncommon event, a prospective study of fungal colonization and infection was conducted. From December 1998 to December 1999, surveillance cultures of the oral cavities and perinea of the 593 of the 781 neonates admitted to the neonatal ICU who were expected to stay for >7 days were performed. Potential environmental reservoirs and possible risk factors for acquisition of C. tropicalis were searched for. Molecular epidemiologic studies by two methods of restriction fragment length polymorphism analysis and two methods of random amplified polymorphic DNA analysis were performed. Seventy-two neonates were colonized by yeasts (12.1%), of which 30 were colonized by Candida albicans, 17 were colonized by C. tropicalis, and 5 were colonized by Candida parapsilosis. From December 1998 to December 1999, 10 cases of fungemia occurred; 6 were due to C. parapsilosis, 2 were due to C. tropicalis, 1 was due to Candida glabrata, and 1 was due to Trichosporon asahii (12.8/1,000 admissions). Fungemia occurred more frequently in colonized than in noncolonized neonates (P < 0.0001). Genetic analysis of 11 colonization isolates and the two late blood isolates of C. tropicalis demonstrated two genotypes. One blood isolate and nine colonization isolates belonged to a single type. The fungemia/colonization ratio of C. parapsilosis (3/5) was greater than that of C. tropicalis (2/17, P = 0.05), other non-C. albicans Candida spp. (1/11, P = 0.02), or C. albicans (0/27, P = 0.05). Extensive environmental cultures revealed no common source of C. tropicalis or C. parapsilosis. There was neither prophylactic use of azoles nor other risk factors found for acquisition of C. tropicalis except for total parenteral nutrition. A substantial risk of colonization by non-C. albicans Candida spp. in the neonatal ICU may lead to a preponderance of C. tropicalis as a significant cause of neonatal fungemia.

Nosocomial transmission of Saccharomyces cerevisiae in bone marrow transplant patients

Saccharomyces cerevisiae is an unusual cause of clinical infection. We describe three bone marrow transplant patients on a haematology unit who developed possible invasive disease with the organism. Two patients died and both these patients appeared to have a related strain of S. cerevisiae. Screening for S. cerevisiae from throat and stool samples revealed four further patients who were carriers. Genotyping of the invasive and carriage strains demonstrated an indistinguishable strain from patients who had been on the unit at the same time, suggesting cross-infection.

Horizontal transmission of Candida parapsilosis candidemia in a neonatal intensive care unit

This report describes the nosocomial acquisition of Candida parapsilosis candidemia by one of the six premature newborns housed in the same room of a neonatal intensive care unit at the Ospedale Santa Chiara, Pisa, Italy. The infant had progeria, a disorder characterized by retarded physical development and progressive senile degeneration. The infant, who was not found to harbor C. parapsilosis at the time of his admission to the intensive care unit, had exhibited symptomatic conjunctivitis before the onset of a severe bloodstream infection. In order to evaluate the source of infection and the route of transmission, two independent molecular typing methods were used to determine the genetic relatedness among the isolates recovered from the newborn, the inanimate hospital environment, hospital personnel, topically and intravenously administered medicaments, and indwelling catheters. Among the isolates collected, only those recovered from the hands of two nurses attending the newborns and from both the conjunctiva and the blood of the infected infant were genetically indistinguishable. Since C. parapsilosis was never recovered from indwelling catheters or from any of the drugs administered to the newborn, we concluded that (i) horizontal transmission of C. parapsilosis occurred through direct interaction between nurses and the newborn and (ii) the conjunctiva was the site through which C. parapsilosis entered the bloodstream. This finding highlights the possibility that a previous C. parapsilosis colonization and/or infection of other body sites may be a predisposing condition for subsequent C. parapsilosis hematogenous dissemination in severely ill newborns.