Targeted short-term fluconazole prophylaxis among very low birth weight and extremely low birth weight infants

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.

Fungal prophylaxis in very low birth weight neonates: nystatin, fluconazole or nothing?

PURPOSE OF REVIEW

To examine recent evidence on the efficacy of antifungal prophylaxis to prevent neonatal systemic fungal infection. The review also aims to examine other relevant data, including the incidence of fungal infection, adverse effects of antifungal therapy and avoidable risk factors.

RECENT FINDINGS

There is strong evidence that systemic fluconazole prophylaxis reduces the incidence of systemic fungal infections, with a trend towards reduction in mortality. However, the preprophylaxis incidence of fungal infection has been very high in the published studies. Fluconazole use is sometimes associated with cholestasis and there are theoretical concerns as well that prophylactic fluconazole will select for fluconazole-resistant organisms and nonalbicans Candida infections. There is reasonable evidence that oral nystatin is effective in preventing fungal infections and at the same time it is inexpensive and well tolerated. The reported incidence of systemic fungal infections is much lower in the UK than in the USA and Italy.

SUMMARY

Oral nystatin prophylaxis is inexpensive, effective and nontoxic and should be used routinely for babies of birth weight less than 1500 g. Systemic fluconazole, which is more toxic and may select for resistant fungi, is probably only indicated when the rate of fungal infection remains high despite introducing measures targeting known risk factors for fungal infection. These measures include introducing enteral feeds early, reducing the duration of parenteral feeding, and reducing the use of broad spectrum antibiotics, particularly cephalosporins. Future studies of prophylactic fluconazole should use oral nystatin, not placebo, as the comparator.

Fluconazole prophylaxis: can we eliminate invasive Candida infections in the neonatal ICU?

PURPOSE OF REVIEW

Owing to the high mortality, risk of neurodevelopmental impairment and end-organ involvement with fungal infections in the neonate, prevention of invasive Candida infections in extremely preterm infants should be a priority for each neonatal ICU.

RECENT FINDINGS

Even with prompt or empiric treatment, mortality and neurodevelopmental impairment is high (57%) in infants <1000 g. Multiple studies have been performed with fluconazole prophylaxis, including a recent multicenter randomized controlled trial. All of the studies have demonstrated efficacy and safety with no increase or emergence of fungal resistance. Analysis of these studies demonstrates that fluconazole prophylaxis decreased the incidence of invasive Candida infections in high-risk infants <1000 g by 91% (P = 0.0004) and all infants <1500 g by 85% (P < 0.0001). The mortality rate from all causes was 25% lower (P = 0.029). Furthermore, studies have demonstrated that all Candida-related mortality can be eliminated in an entire neonatal ICU by targeting fluconazole prophylaxis in infants <1000 g.

SUMMARY

Targeting fluconazole prophylaxis to infants who are either <1000 g or < or =27 weeks is highly effective, safe and inexpensive, and can eliminate these infections as a cause of neurodevelopmental impairment and mortality.

Fluconazole prophylaxis for prevention of invasive fungal infections in targeted highest risk preterm infants limits drug exposure

OBJECTIVE

Previous reports suggest a benefit of fluconazole prophylaxis in extremely low birth weight (ELBW) infants <1000 g. Our aim was to evaluate if limiting fluconazole prophylaxis to targeted highest risk infants effectively prevents invasive fungal infections, has no undesired side effects and limits unnecessary drug exposure.

STUDY DESIGN

This nonrandomized retrospective pre-post intervention study compared two groups of infants: (1) Infants <26 weeks gestation and/or <750 g birth weight, requiring central vascular access and admitted to the Monroe Carell Jr Children's Hospital at Vanderbilt neonatal intensive care unit (NICU) prior to 5 days of age, who received fluconazole prophylaxis and (2) a matched control group from the year prior to prophylaxis. This target population was selected for fluconazole prophylaxis based on prior infection control data from our institution and a number needed to treat of <15 to prevent one episode of fungemia. Following implementation and integration through the institution's computerized physician order entry (CPOE) system, provider adherence to the protocol was assessed during the prophylaxis period.

RESULT

A total of 86 patients were included in the study, 44 in the no-prophylaxis group and 42 in the prophylaxis group. In the targeted prophylaxis group, no invasive fungal infections were observed as compared to nine infants with invasive infections in the no-prophylaxis group (P=0.004). No significant adverse effects were recorded. Targeting the highest risk infants reduced the number of infants <1000 g requiring prophylaxis from 80 to 42 (48% reduction) with no preventable infection missed. Provider compliance was 91% following implementation of this protocol through the CPOE system using a standardized order set.

CONCLUSION

Targeting the highest risk infants for fluconazole prophylaxis through CPOE can effectively prevent invasive fungal infections and limit drug exposure with no unwanted side effects.

Fluconazole prophylaxis in extremely low birth weight neonates reduces invasive candidiasis mortality rates without emergence of fluconazole-resistant Candida species

OBJECTIVE

We evaluated the impact of fluconazole prophylaxis for extremely low birth weight infants on invasive candidiasis incidence, invasive candidiasis-related mortality rates, and fluconazole susceptibility of Candida isolates.

METHODS

Extremely low birth weight infants <5 days of age, except those with liver dysfunction, were eligible for fluconazole prophylaxis. NICU infants (all birth weights) with invasive candidiasis between April 2002 and March 2006 were compared with those with invasive candidiasis before fluconazole prophylaxis (2000-2001).

RESULTS

Twenty-two infants had invasive candidiasis (all candidemia) during fluconazole prophylaxis; before fluconazole prophylaxis, there were 19 cases (candidemia: 17 cases; meningitis: 2 cases). Invasive candidiasis incidence in NICU infants decreased from 0.6% (19 of 3012 infants) before fluconazole prophylaxis to 0.3% (22 of 6393 infants) in 2002-2006 and that in extremely low birth weight infants decreased 3.6-fold. No Candida-attributable deaths occurred during 2002-2006 fluconazole prophylaxis, compared with 4 (21%) before fluconazole prophylaxis. The onset of invasive candidiasis was later during 2002-2006 (23.5 vs 12 days), but risk factors were similar. The invasive candidiasis species distribution remained stable. Of 409 infants who received fluconazole prophylaxis, 119 (29%) received 42 days. Shorter fluconazole prophylaxis duration was related to intravenous access no longer being necessary in 242 cases (59%), noninvasive candidiasis-related death in 29 (7%), hospital transfer in 8 (2%), invasive candidiasis diagnosis in 8 (2%), and transient increase in serum transaminase levels in 4 (1%). One hundred twenty-seven infants (31%) who received fluconazole prophylaxis developed cholestasis during hospitalization, two thirds of whom had other predisposing conditions. On multivariate logistic regression necrotizing enterocolitis and increasing days of total parenteral nutrition, but not increasing number of doses on days of fluconazole, were significantly associated with the development of cholestasis.

CONCLUSION

During 4 years of fluconazole prophylaxis, the incidence of invasive candidiasis and invasive candidiasis-associated mortality rates in extremely low birth weight infants were reduced significantly, without the emergence of fluconazole-resistant Candida species.

Neonatal Candida spp. infections: an update

Candida-related morbidity and mortality have increased in neonatal intensive care units (NICUs) in the last 20 years. Invasive fungal infections (IFIs) in preterm infants are associated with high severity, high attributable mortality, substantial morbidity and poor outcomes owing to the frequent association with late neurodevelopmental impairment and retinopathy of prematurity in the survivors. Preterm very-low birth weight infants in NICUs have a specific, increased risk for IFIs, mainly because up to 60% of them may become colonized during their first month of life. Prevention of Candida colonization and infection is the key in these settings of unique patients, and solid data have recently been added to the very first promising results obtained in the early 2000’s with administation of fluconazole. In a multicenter randomized trial, this azole caused a striking reduction in the incidences of Candida spp. colonization (from 33 to 9%) and infection (from 13.2 to 3.2%), with no occurrence of significant side-effects and no signs of selective resistance during the 15-month study period. New guidelines incorporating the recent multicenter results are urgently needed.

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.

Use of Lactobacillus casei subspecies Rhamnosus GG and gastrointestinal colonization by Candida species in preterm neonates

Candida species increasingly cause morbidity and mortality in the premature infant in neonatal intensive care units, and the gut reservoir is the site from which dissemination most frequently starts in such patients. Specific antifungal prophylaxis is the most suitable strategy with which to limit the severity and the frequent neurodevelopmental impairment in survivors that is associated with neonatal invasive fungal infections. Recent interest has focused on the use of probiotics for the treatment of several diseases in neonatal patients. Pilot studies have implicated these organisms in necrotizing enterocolitis, sepsis, and urinary tract infections. Other applications of probiotic therapy in preterm neonates may also include the prevention of fungal colonization and of Candida-related disorders. Probiotics could provide an innovative and less invasive approach because they modify the bowel flora by colonizing the gastrointestinal tract. Basic research has shown that in mice models, the Lactobacillus casei subsp Rhamnosus GG (LGG) is effective in preventing Candida gut colonization and systemic dissemination. A pilot, randomized, double-blind, placebo-controlled trial in human preterm neonates has demonstrated that LGG administered in the first month of life significantly reduces enteric Candida colonization. The present article summarizes the state of the art about probiotics and Candida-related diseases in the preterm neonate and emphasizes the need for further investigations to determine unequivocally the possible role of LGG in the prevention and management of the fungal diseases in preterm neonates.

Selective fluconazole prophylaxis in high-risk babies to reduce invasive fungal infection

OBJECTIVES

To evaluate the impact of selective fluconazole prophylaxis on incidence of invasive fungal infection and emergence of fluconazole resistance in neonatal intensive care.

DESIGN

Retrospective study of very low birthweight (VLBW) babies (<1500 g birth weight) admitted to a neonatal intensive care unit (NICU) in the period 1 year before and after the implementation of an antifungal prophylaxis guideline.

PATIENTS

VLBW babies with an additional risk factor: colonisation of Candida species from surface sites with a central venous catheter; third generation cephalosporin treatment; or total duration of antibiotic treatment >10 days. Fluconazole protocol: Fluconazole 6 mg/kg for 3 weeks. Dose interval is every 72 h during the first 2 weeks of life. Thereafter, dose interval is reduced to every 48 h until 3 weeks old when daily fluconazole is given. Fluconazole is administered orally when enteral feeding achieved.

RESULTS

121 and 107 VLBW babies were admitted to the NICU in the year before and after the guideline was implemented, respectively. Data were available in 110 and 102 charts. 33/110 and 31/102 babies were eligible for fluconazole prophylaxis in the period before and after guideline implementation. 6/33 babies eligible for prophylaxis developed culture proven Candida sepsis before compared with no (0/31) babies after the guideline was implemented (p = 0.03). One baby (1/31) did develop probable Candida sepsis in the post guideline implementation period. During both study periods all Candida isolates remained fully susceptible to fluconazole.

CONCLUSIONS

Selective antifungal prophylaxis has reduced invasive fungal sepsis in one NICU without evidence of fluconazole resistance emerging.

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

BACKGROUND

Invasive fungal infection is an important cause of mortality and morbidity in very low birth weight infants. Early diagnosis is difficult, and treatment is often delayed. The available data are insufficient to conclude that topical/oral prophylaxis (usually nystatin and/or miconazole) prevents invasive fungal infection or mortality in very low birth weight infants. Systemic antifungal agents (usually azoles) are increasingly used as prophylaxis against invasive fungal infection.

OBJECTIVES

To assess the effect of prophylactic systemic antifungal therapy on mortality and morbidity in very low birth weight infants.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Cochrane Controlled Trials Register (The Cochrane Library, Issue 2, 2007), MEDLINE (1966 - May 2007), EMBASE (1980 - May 2007), conference proceedings, and previous reviews.

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

Seven eligible trials enrolling a total of 638 participating infants were identified. Meta-analysis of data from four trials that compared prophylactic fluconazole versus placebo revealed a statistically significant reduction in the risk of invasive fungal infection in the infants who received prophylaxis [typical relative risk: 0.23 (95% confidence interval 0.11, 0.46); typical risk difference: -0.11 (95% confidence interval -0.16, -0.06); number needed to treat: 9 (95% confidence interval 6, 17)]. There was no statistically significant difference in the risk of death prior to hospital discharge [typical relative risk: 0.61 (95% confidence interval 0.37, 1.03); typical risk difference: -0.05 (95% confidence interval -0.11, -0.00)]. Only one trial reported long term neurodevelopmental outcomes. There were no statistically significant differences in the incidence of developmental delay, or motor or sensory neurological impairment in children assessed at a median age of 16 months. One small trial that compared systemic versus oral/topical prophylaxis did not detect a statistically significant effect on invasive fungal infection or mortality. Two trials compared different dosing regimens of prophylactic intravenous fluconazole. These did not detect any significant differences in infection rates or mortality.

AUTHORS' CONCLUSIONS

Prophylactic systemic antifungal therapy reduces the incidence of invasive fungal infection in very low birth weight infants. This finding should be interpreted cautiously. The incidence of invasive fungal infection was very high in the control groups of some of the included trials. Furthermore, the trials may have been affected by ascertainment bias since use of prophylactic fluconazole may reduce the sensitivity of microbiological culture for detecting fungi in blood, urine, or cerebrospinal fluid. Meta-analysis does not demonstrate a statistically significant effect on overall mortality rates, but the 95% confidence interval around this estimate of effect is wide. There are currently only limited data on the long-term neurodevelopmental consequences for infants exposed to this intervention. In addition, there is a need for further data on the effect of the intervention on the emergence of organisms with antifungal resistance.

A multicenter, randomized trial of prophylactic fluconazole in preterm neonates

BACKGROUND

Invasive candida infections are a major cause of morbidity and mortality in preterm infants. We performed a multicenter, randomized, double-blind, placebo-controlled trial of fluconazole for the prevention of fungal colonization and infection in very-low-birth-weight neonates.

METHODS

During a 15-month period, all neonates weighing less than 1500 g at birth from eight tertiary Italian neonatal intensive care units (322 infants) were randomly assigned to receive either fluconazole (at a dose of either 6 mg or 3 mg per kilogram of body weight) or placebo from birth until day 30 of life (day 45 for neonates weighing <1000 g at birth). We performed weekly surveillance cultures and systematic fungal susceptibility testing.

RESULTS

Among infants receiving fluconazole, fungal colonization occurred in 9.8% in the 6-mg group and 7.7% in the 3-mg group, as compared with 29.2% in the placebo group (P<0.001 for both fluconazole groups vs. the placebo group). The incidence of invasive fungal infection was 2.7% in the 6-mg group and 3.8% in the 3-mg group, as compared with 13.2% in the placebo group (P=0.005 for the 6-mg group and P=0.02 for the 3-mg group vs. the placebo group). The use of fluconazole did not modify the relationship between colonization and the subsequent development of invasive fungal infection. Overall mortality was similar among groups, as was the incidence of cholestasis. No evidence for the emergence of resistant candida species was observed, but the study did not have substantial power to detect such an effect.

CONCLUSIONS

Prophylactic fluconazole reduces the incidence of colonization and invasive candida infection in neonates weighing less than 1500 g at birth. The benefit of treating candida colonization is unclear. (Current Controlled Trials number, ISRCTN85753869 [controlled-trials.com]).

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.

Risk of resistance associated with fluconazole prophylaxis: systematic review

BACKGROUND

Several studies have shown that fluconazole prophylaxis reduces the risk of fungal colonization and of invasive fungal infection in high-risk patients with minimal toxicity. This systematic review was designed to estimate the risk of emergence of colonization and infection either with azole susceptible-dose dependent or with resistant strains.

METHODS

We searched Medline, EMBASE, the Cochrane Collaboration database and our own files for randomized controlled trials assessing the effect of fluconazole on the incidence of fluconazole-resistant strains.

RESULTS

This systematic review of randomized clinical trials shows that fluconazole prophylaxis increases the risk for colonization with fluconazole susceptible-dose dependent or with resistant yeasts, the percentage of non-albicans Candida isolates and the percentage of fluconazole susceptible-dose dependent or resistant fungal isolates. Fluconazole prophylaxis did not significantly affect the risk of invasive disease with fluconazole susceptible-dose dependent or resistant fungi. The sample size was too small to assess the effect of fluconazole prophylaxis on the risk for breakthrough infections with non-albicans Candida.

CONCLUSION

Evidence from randomized trials suggests that fluconazole prophylaxis increases the risk for colonization with fluconazole susceptible-dose dependent or with resistant fungi, but does not significantly affect the risk for invasive infections with fluconazole susceptible-dose dependent or with resistant fungi. The risk for breakthrough infections remains a concern and needs to be addressed in large prospective studies.

Antifungal prophylaxis to prevent neonatal candidiasis: a survey of perinatal physician practices

BACKGROUND

Bloodstream infections with Candida species have a high mortality rate in very low birth weight infants. Preliminary data suggest that prophylaxis with fluconazole reduces the incidence of colonization and invasive Candida infections in high-risk, very low birth weight neonates. The extent of antifungal prophylaxis use to prevent neonatal candidemia is unknown.

METHODS

We surveyed a 20% random sample of the members of the American Academy of Pediatrics Section on Perinatal Pediatrics. We collected information on prophylactic agents used, indications for use, and rationale for reported practices.

RESULTS

A total of 219 (47%) of 469 members sampled responded; 3 clinicians who did not provide care to very low birth weight infants were excluded. Antifungal prophylaxis use was reported by 73 (34%) respondents. Agents used included intravenous fluconazole (66%), oral nystatin (59%), and intravenous amphotericin B (21%). Decreased birth weight or early gestational age was the most frequent indication to start prophylaxis (57 [78%]). Respondents who did not use antifungal prophylaxis compared with respondents who used fluconazole prophylaxis were significantly more likely to have concerns about (1) the emergence of antifungal resistance, (2) unclear criteria on which to base the decision to start prophylaxis, and (3) the need for clarification of the role of surveillance cultures.

CONCLUSIONS

Although preliminary data suggest that fluconazole is efficacious to prevent candidemia in a subset of neonates, this practice is not used widely by clinicians who care for very low birth weight infants. Additional efficacy studies should address the emergence of antifungal resistance or clarification of criteria to initiate prophylaxis, including the role of surveillance cultures.

Fluconazole prophylaxis in extremely low birth weight infants: association with cholestasis

BACKGROUND

Extremely low birth weight (ELBW) infants are at increased risk for invasive candidiasis and associated morbidity and mortality. The use of fluconazole prophylaxis in this population has raised a benefit versus risk concern among clinicians.

OBJECTIVES

To evaluate the effectiveness and safety of fluconazole prophylaxis in ELBW infants.

STUDY DESIGN

ELBW infants (BW<or=1,000 g) born during the pre-prophylaxis era (PPE, January 1998-February 2002) were compared with prophylaxis era (PE, March 2002-September 2005). Infants born during PE received fluconazole prophylaxis for 6 weeks, as long as they had intravenous access. Demographic and clinical data were collected. The two groups were compared for baseline demographics, risk factors for candidiasis, the incidence of invasive candidiasis, liver enzymes, alkaline phosphatase, and bilirubin (total and direct).

RESULTS

Nine out of 137 infants (6.6%) developed invasive candidiasis during PPE compared to none of 140 (0%) during PE (P=0.006). During PE, 60/140 (42.9%) infants developed conjugated hyperbilirubinemia compared to 12/137 (8.8%) during PPE (P<0.001).

CONCLUSION

Although a fluconazole prophylaxis regimen for ELBW infants was effective in preventing invasive candidiasis, an increase in the incidence of conjugated hyperbilirubinemia was observed. Further studies are needed to evaluate the safety of fluconazole prophylaxis in this population.