Excess costs of hospital care associated with neonatal candidemia

Disseminated Disease After Candidemia in Children and Young Adults: Epidemiology, Diagnostic Evaluation and Risk Factors

BACKGROUND

Treatment of candidemia may be complicated by hematogenous dissemination. Limited data exist to guide decision-making regarding the evaluation for disseminated disease. We sought to describe the epidemiology of invasive disease after candidemia, report the diagnostic evaluations performed and identify risk factors for disseminated disease.

METHODS

We performed a retrospective single-center study of candidemia from January 1, 2012 to December 31, 2022. Disseminated candidiasis was defined as radiologic findings consistent with end-organ disease, abnormal ophthalmologic exam or growth of Candida spp. from a sterile site after an episode of candidemia. A multilevel regression model was used to identify risk factors for dissemination.

RESULTS

The cohort included 124 patients with 144 episodes of candidemia. Twelve patients died before an evaluation for dissemination occurred. Only 107/132 patients underwent evaluation for dissemination. Tests obtained included abdominal imaging (93/132), echocardiography (91/132), neuroimaging (45/132) and chest imaging (38/132). A retinal examination was performed in 90/132 patients. Overall, 27/107 patients (25%) had disseminated disease. Frequently identified sites of dissemination were lungs and abdominal organs. Regression modeling identified prematurity [adjusted odds ratio (aOR): 11.88; 95% confidence interval (CI): 1.72-81.90] and mitochondrial and genetic disease (aOR: 5.66; 95% CI: 1.06-30.17) as risk factors for disseminated candidiasis. Each additional day of candidemia increased the odds of dissemination (aOR: 1.36; 95% CI: 1.12-1.66).

DISCUSSION

In a heterogeneous cohort of patients, disseminated candidiasis was common. Evaluation for disseminated disease was variable. Those with persistent candidemia had significantly increased risk of dissemination and should undergo a standardized evaluation for disseminated disease.

Recurrent Candidemia: Trends and Risk Factors Among Persons Residing in 4 US States, 2011-2018

Background

Candidemia is a common healthcare-associated infection with high mortality. Estimates of recurrence range from 1% to 17%. Few studies have focused on those with recurrent candidemia, who often experience more severe illness and greater treatment failure. We describe recurrent candidemia trends and risk factors.

Methods

We analyzed population-based candidemia surveillance data collected during 2011-2018. Persons with >1 episode (defined as the 30-day period after a positive Candida species) were classified as having recurrent candidemia. We compared factors during the initial episode between those who developed recurrent candidemia and those who did not.

Results

Of the 5428 persons identified with candidemia, 326 (6%) had recurrent infection. Recurrent episodes occurred 1.0 month to 7.6 years after any previous episode. In multivariable logistic regression controlling for surveillance site and year, recurrent candidemia was associated with being 19-44 years old (vs ≥65 years; adjusted odds ratio [aOR], 3.05 [95% confidence interval {CI}, 2.10-4.44]), being discharged to a private residence (vs medical facility; aOR, 1.53 [95% CI, 1.12-2.08]), hospitalization in the 90 days prior to initial episode (aOR, 1.66 [95% CI, 1.27-2.18]), receipt of total parenteral nutrition (aOR, 2.08 [95% CI, 1.58-2.73]), and hepatitis C infection (aOR, 1.65 [95% CI, 1.12-2.43]).

Conclusions

Candidemia recurrence >30 days after initial infection occurred in >1 in 20 persons with candidemia. Associations with younger age and hepatitis C suggest injection drug use may play a modifiable role. Prevention efforts targeting central line care and total parenteral nutrition use may help reduce the risk of recurrent candidemia.

The landscape of candidemia during the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic has resulted in unprecedented healthcare challenges, and COVID-19 has been linked to secondary infections. Candidemia, a fungal healthcare-associated infection, has been described in patients hospitalized with severe COVID-19. However, studies of candidemia and COVID-19 co-infection have been limited in sample size and geographic scope. We assessed differences in patients with candidemia with and without a COVID-19 diagnosis.

METHODS

We conducted a case-level analysis using population-based candidemia surveillance data collected through the Centers for Disease Control and Prevention's Emerging Infections Program during April-August 2020 to compare characteristics of candidemia patients with and without a positive test for COVID-19 in the 30 days before their Candida culture using chi-square or Fisher exact tests.

RESULTS

Of the 251 candidemia patients included, 64 (25.5%) were positive for SARS-CoV-2. Liver disease, solid organ malignancies, and prior surgeries were each >3 times more common in patients without COVID-19 co-infection, whereas intensive care unit-level care, mechanical ventilation, having a central venous catheter, and receipt of corticosteroids and immunosuppressants were each >1.3 times more common in patients with COVID-19. All cause in-hospital fatality was two times higher among those with COVID-19 (62.5%) than without (32.1%).

CONCLUSIONS

One quarter of candidemia patients had COVID-19. These patients were less likely to have certain underlying conditions and recent surgery commonly associated with candidemia and more likely to have acute risk factors linked to COVID-19 care, including immunosuppressive medications. Given the high mortality, it is important for clinicians to remain vigilant and take proactive measures to prevent candidemia in patients with COVID-19.

The Elusive Anti-Candida Vaccine: Lessons From the Past and Opportunities for the Future

Candidemia is a bloodstream fungal infection caused by Candida species and is most commonly observed in hospitalized patients. Even with proper antifungal drug treatment, mortality rates remain high at 40–50%. Therefore, prophylactic or preemptive antifungal medications are currently recommended in order to prevent infections in high-risk patients. Moreover, the majority of women experience at least one episode of vulvovaginal candidiasis (VVC) throughout their lifetime and many of them suffer from recurrent VVC (RVVC) with frequent relapses for the rest of their lives. While there currently exists no definitive cure, the only available treatment for RVVC is again represented by antifungal drug therapy. However, due to the limited number of existing antifungal drugs, their associated side effects and the increasing occurrence of drug resistance, other approaches are greatly needed. An obvious prevention measure for candidemia or RVVC relapse would be to immunize at-risk patients with a vaccine effective against Candida infections. In spite of the advanced and proven techniques successfully applied to the development of antibacterial or antiviral vaccines, however, no antifungal vaccine is still available on the market. In this review, we first summarize various efforts to date in the development of anti-Candida vaccines, highlighting advantages and disadvantages of each strategy. We next unfold and discuss general hurdles encountered along these efforts, such as the existence of large genomic variation and phenotypic plasticity across Candida strains and species, and the difficulty in mounting protective immune responses in immunocompromised or immunosuppressed patients. Lastly, we review the concept of “trained immunity” and discuss how induction of this rapid and nonspecific immune response may potentially open new and alternative preventive strategies against opportunistic infections by Candida species and potentially other pathogens.

Candidemia and invasive candidiasis among hospitalized neonates and pediatric patients

OBJECTIVE

To investigate the epidemiology, treatment, length of stay (LOS) and costs for neonatal and pediatric inpatients with invasive candidiasis (IC).

METHODS

The Cerner Health Facts Database was used to assess inpatients (2005-2014) identified by positive blood or cerebrospinal fluid (CSF) Candida cultures. Log-transformed LOS and cost were examined in candidemia-only patients (n = 191) using multivariable linear regression.

RESULTS

A total of 202 patients had a positive culture (blood: n = 192; CSF: n = 10; both: n = 2). The most prevalent species were C. parapsilosis (n = 70, 34.7%), and C. albicans (n = 66, 32.7%). Mean (SD) age was 5 (5.5) years; 30 (14.9%) patients were <4 months. Comorbidities included sepsis (n = 85, 42.1%), coagulation disorders (n = 57, 28.2%), cancer (n = 64, 31.7%), and low birthweight (n = 26, 12.9%). Antifungals (AFs) included azoles (57.4%), polyenes (28.7%), and echinocandins (35.1%); 20.8% of patients received no AF during their encounter. The mean (SD) cost per encounter was $97,392 ($149,253), with a mean (SD) LOS of 45.6 (59.5) days and 9.9% mortality at discharge. Results were similar across Candida species. In regression analysis, intensive care unit (ICU) exposure, central catheter, sepsis, AF >48 hours prior to index culture, and age <4 months were associated with increased LOS; treatment at a non-teaching hospital was associated with reduced LOS (p < .05). AF use >48 hours before index, in-hospital mortality, Midwest region and ventricular shunt were associated with increased cost (p ≤ .05).

CONCLUSIONS

This analysis confirms the association between pediatric candidemia and increased resource utilization and LOS. Given high observed rates of potential under-treatment, an opportunity may exist to improve AF therapy in this population.

Cost Analysis of Fluconazole Prophylaxis for Prevention of Neonatal Invasive Candidiasis

BACKGROUND

Fluconazole prophylaxis (FP) in premature infants is well studied and has been shown to decrease invasive candidiasis (ICs). IC in neonates has significant financial costs; determining the cost-benefit of FP may provide additional justification for targeting high-risk neonates. We aimed to determine the IC rate in premature infants at which FP is cost-beneficial.

METHODS

A decision tree cost-analysis model using cost of FP related to costs associated with IC was used. We searched PubMed for all papers that used intravenous FP and reported rates of IC in very low birth weight neonates. Average IC rates in those who received FP (2.0%; range, 0-6.1%) and in those who did not receive FP (9.2%; range, 0-20.5%) were used. Incremental hospital costs because of IC and for FP were retrieved from the literature. Sensitivity analysis was performed to determine the incremental cost of FP across the range of published IC rates.

RESULTS

The average cost per patient attributed to IC in patients receiving FP was $785 versus $2617 in those not receiving FP. Sensitivity analysis demonstrates the rate of IC would need to be <2.8% for FP to lose its cost-benefit. In Monte Carlo simulation, targeting infants <1000 g would lead to $50,304,333 in cost savings per year in the United States.

CONCLUSIONS

FP provides a cost-advantage across most IC rates seen in the youngest premature infants. Using a rate of 2.8% for their individual high-risk neonatal intensive care unit patients, providers can determine if FP is cost-beneficial in determining for whom to provide IC prophylaxis.

Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Invasive Candidiasis

Invasive candidiasis is a collective term that refers to a group of infectious syndromes caused by a variety of species of Candida, 5 of which cause most cases. Candidemia is the most commonly recognized syndrome associated with invasive candidiasis. Certain conditions may influence the likelihood for one species versus another in a specific clinical scenario, and this can have important implications for selection of antifungal therapy and the duration of treatment. Molecular diagnostic technology plays an ever-increasing role as an adjunct to traditional culture-based diagnostics, offering significant potential toward improvement in patient care.

Molecular surveillance of candidemia due to Candida albicans among cancer patients during 2009 to 2013 by microsatellite typing

BACKGROUND

Since the high morbidity and mortality of candidemia among cancer patients, the epidemiology has been underlined. In recent years, Candida species genotyping has been established, which could provide detail characteristics of epidemiology and has been underscored for candidemia preventing strategies.

METHODS

Data of cancer patients with candidemia and hospitalized in Tianjin Medical University Cancer Institute and Hospital (TMUCIH) during 2009-2013 were reviewed. Species identification was carried out by using VITEK-2 Compact. Microsatellite typing was performed for molecular analysis. SPSS 20.0 and MVSP 3.22 software were used for statistical and clustering analysis, respectively.

RESULTS

Total of 36 isolates of Candida albicans were recovered from 36 cancer patients with nosocomial candidemia in TMUCIH during the period of 2009-2013 included in the study. Total of 17 genotypes were identified and 2 of them were endemic genotypes, which caused 21 (58.3%) of 36 episodes of candidemia. Hepatobiliary oncology, ICU and gastrointestinal oncology were the main wards of infections due to endemic strains. Gastrointestinal cancer and insertion of a nasogastric tube were the predictors of infections caused by endemic strains (p = 0.014 and p = 0.041, respectively). For the 36 cases, crude mortality was up to 30.6%, and there was no significant difference between infections due to endemic and non-endemic strains (p = 0.077).

CONCLUSIONS

This study proved that endemic stains of C. albicans could exist for a long period and mainly in a few wards. Patients with gastrointestinal cancer or nasogastric tube insertion were more sensitive to endemic C. albicans.

Risk prediction for invasive candidiasis

Over past few years, treatment of invasive candidiasis (IC) has evolved from targeted therapy to prophylaxis, pre-emptive and empirical therapy. Numerous predisposing factors for IC have been grouped together in various combinations to design risk prediction models. These models in general have shown good negative predictive value, but poor positive predictive value. They are useful in selecting the population which is less likely to benefit from empirical antifungal therapy and thus prevent overuse of antifungal agents. Current article deals with various risk prediction models for IC and their external validation studies.

Oral colonization: a possible source for candidemia in low-weight neonates

OBJECTIVE

To check the oral colonization in neonates at high-risk and to associate these cases with candidemia.

SUBJECTS AND METHODS

This study was conducted in the NICU. For six months, 125 high-risk neonates were investigated for oral colonization and septicemia by yeasts. From this total, 19 neonates had yeasts on the oral mucosae and 12 neonates developed fungemia. All of the 12 neonates with fungemia were included in the amount of 19 who have presented oral colonization by yeasts.

RESULTS

There was a species concordance between the yeasts of the oral mucosae and the blood in 6 neonates (50%) among the 12 neonates with oral colonization and septicemia at the same time. The yeasts isolated in these 6 cases regarding the species concordance were Candida albicans (5 cases, 83.4%) and Candida parapsilosis (1 case, 16.6%). All of the cases involving an association were confirmed by PFGE. All of the strains of yeasts involved in oral colonization and also blood presented the same karyotype. A total of 66.6% of the patients with strains in agreement progressed to death.

CONCLUSION

The results indicate the relevance of monitoring the oral microbiota, as a possible source of fungal infection, and assisting to develop appropriate therapeutic strategy.

Laboratory-confirmed, health care-associated bloodstream infections in Jordan: a matched cost and length of stay study

BACKGROUND

No studies have been carried out in Jordan to examine length of stay (LOS) and extra cost associated with health care-associated bloodstream infections (HCABSIs). This study aims to estimate the extra LOS and cost associated with HCABSIs among adult hospitalized Jordanian patients.

METHODS

Five-year data were retrieved from 1 large university-affiliated hospital in Jordan. Matched case-control design was used in this study. Cases were determined based on confirmed positive blood culture after 48 hours of admission. Matching criteria were age (±5 years), gender, admission diagnosis, and LOS in comparison group equal to the LOS (±5%) before blood culture for the case group.

RESULTS

Of the total 445 infected patients 125 (28.1%) were matched with uninfected patients. The mean LOS after infection for cases was 12.1 days (standard deviation [SD] = 17.2) compared with 8.3 (SD = 7.9) days for the controls (P = .02). The total mean inflation-adjusted charges for cases was M (mean) = US $7,426, SD = $7,252 compared with M = $3,274, SD = $4,209 for controls, P < .001. Using multiple regression modeling, LOS after acquiring HCABSIs, admission to critical care units, and being infected with HCABSIs were significant predictors of patients' total charges.

CONCLUSION

Figures generated from this can be used to inform health care researchers, policy makers, and professionals about the impact of HCABSIs.

Risk factors for invasive candidiasis in infants >1500 g birth weight

BACKGROUND

We describe the incidence, risk factors and outcomes of invasive candidiasis in infants >1500 g birth weight.

METHODS

We conducted a retrospective cohort study of infants >1500 g birth weight discharged from 305 neonatal intensive care units in the Pediatrix Medical Group from 2001 to 2010. Using multivariable logistic regression, we identified risk factors for invasive candidiasis.

RESULTS

Invasive candidiasis occurred in 330 of the 530,162 (0.06%) infants. These were documented from positive cultures from ≥1 of these sources: blood (n = 323), cerebrospinal fluid (n = 6) or urine from catheterization (n = 19). Risk factors included day of life >7 (odds ratio [OR]: 25.2; 95% confidence interval: 14.6-43.3), vaginal birth (OR: 1.6 [1.2-2.3]), exposure to broad-spectrum antibiotics (OR: 1.6 [1.1-2.4]), central venous line (OR: 1.8 [1.3-2.6]) and platelet count <50,000/mm (OR: 3.7 [2.1-6.7]). All risk factors had poor sensitivities, low positive likelihood ratios and low positive predictive values. The combination of broad-spectrum antibiotics and low platelet count had the highest positive likelihood ratio (46.2), but the sensitivity of this combination was only 4%. Infants with invasive candidiasis had increased mortality (OR: 2.2 [1.3-3.6]).

CONCLUSIONS

Invasive candidiasis is uncommon in infants >1500 g birth weight. Infants at greatest risk are those exposed to broad-spectrum antibiotics and with platelet counts of <50,000/mm(3).

Risk factors for persistent candidemia infection in a neonatal intensive care unit and its effect on mortality and length of hospitalization

OBJECTIVE

Candida infections cause substantial morbidity and mortality in neonates. Persistent candidemia has not been associated with increased risk of mortality compared with candidemia of shorter duration. This study sought to determine whether persistent candidemia was associated with increased length of hospitalization or mortality in neonates.

STUDY DESIGN

A chart review was conducted of neonates with Candida bloodstream infections (n=37). Demographic, laboratory, pharmacy, nutrition and discharge data were abstracted. Contingency table analysis and logistic regression were used to analyze variables associated with persistent candidemia and mortality. The relationship between length of hospitalization and persistent candidemia was assessed with k-sample equality of medians test.

RESULT

Nine patients (24%) had persistent candidemia. Increased time between blood culture draw and initial antifungal therapy was associated with increased incidence of persistent candidemia (P=0.03). Five patients (14%) died before hospital discharge; however, no deaths were attributed to persistent candidemia. Length of hospitalization was not increased with persistent candidemia. A decrease in the ratio of enteral feeding days to hyperalimentation days before collection of the first positive blood culture was significantly associated with an increase in all-cause mortality (P=0.03) and death attributed to candidemia (P=0.04). The risk of all-cause mortality decreased with a history of receiving any enteral feedings before the first positive blood culture (P=0.04), as did death attributed to candidemia (P=0.02).

CONCLUSION

A duration of >1 day between the time of blood culture and the initial dose of systemic antifungal treatment places neonates at increased risk for developing persistent candidemia; however, this is not associated with increased mortality.

Fluconazole use and safety in the nursery

Fluconazole is a triazole antifungal agent that is widely used in the nursery. It is available in both intravenous and oral formulation, and is active against most of the fungal pathogens that require treatment when retrieved from culture samples in neonatal intensive care units. Although clinical use has been wide for over 15 years, there have been small safety and efficacy studies completed in young infants. Randomised clinical trials assessing effectiveness of this agent in prevention of systemic fungal infections in neonates have been published in the last decade, and one large additional randomised study has been recently completed. Nevertheless, a certain degree of uncertainty still exists regarding the kinetics and appropriate dosing of this agent in premature and term infants, as well as regarding safety. Areas of poignant debate include the feasibility of loading dose strategies, appropriate dosages in the early days of life in the different subgroups of preterm infants, and long-term safety of fluconazole administered in prophylaxis during the first weeks of life in extremely premature infants. This paper reviews the most recent evidence on fluconazole and its role in the NICU settings.

Length of stay and charges associated with health care-acquired bloodstream infections

BACKGROUND

Although many studies have examined outcomes of health care-associated bloodstream infections (HCABSIs), population-based estimates of length of stay (LOS) and costs have seldom been reported.

OBJECTIVES

Our objective was to generate US national estimates of LOS and costs associated with HCABSIs using the 2003 National Inpatient Sample (NIS).

METHODS

This study utilized a matched case-control design to estimate LOS and costs associated with HCABSIs based on the 2003 (NIS). A special set of ICD-9-CM codes was used to identify cases. A 1:1 matching procedure was used in which HCABSIs in patients were matched with uninfected patients based on age, sex, and admission diagnosis. We performed weighted analysis to construct population estimates and their standard deviations for LOS and total charges.

RESULTS

After applying the case finding criteria, 113,436 HCABSI cases were identified. The weighted mean LOS for HCABSIs cases was 16.0 days compared with 5.4 days for the control group (P < .001). The weighted mean total charges for patients with HCABSIs were $85,813 ($110,183 US in 2010) compared with $22,821 ($29,302 US in 2010) for uninfected patients (P < .001). We estimated that, in 2003, HCABSIs potentially cost the US economy nearly $29 billion ($37.24 billion US in 2010).

CONCLUSION

This study estimated the economic burden of HCABSIs on the US national economy. With some modifications, the annually published NIS data could be useful as a national surveillance tool for health care adverse events including HCABSIs.

The use of antifungal therapy in neonatal intensive care

Invasive fungal infections remain a significant cause of infection-related mortality and morbidity in preterm infants. Central nervous system involvement is the hallmark of neonatal candidiasis, differentiating the disease's impact on young infants from that among all other patient populations. Over the past decade, the number of antifungal agents in development has grown, but most are not labeled for use in newborns. We summarize the findings of several antifungal studies that have been completed to date, emphasizing those including infant populations. We conclude that more studies are required for antifungals to be used safely and effectively in infants.

Neonatal intensive care unit candidemia: epidemiology, risk factors, outcome, and critical review of published case series

Evaluation of epidemiological trends, risk factors, and clinical outcome associated with candidemia at a neonatal intensive care unit is reported. From January 2005 to December 2009, forty candidemia cases were identified. C. albicans and C. parapsilosis were the most common species recovered (69 and 24%, respectively). All C. parapsilosis strains were susceptible to antifungals, whereas, C. albicans exhibited higher resistance rates to azoles. Low birth weight, low gestational age, presence of central lines, endotracheal intubation, total parenteral nutrition, previous use of antibiotics, steroids, previous episode(s) of bacteremia and prolonged stay in intensive care unit were common features associated with candidemia. C. albicans was most often isolated from extremely low birth weight neonates as compared to non-albicans Candida (P < 0.01). Mortality rate was 35.7% and was associated with low gestational age (P < 0.01), low birth weight (P < 0.01), and presence of renal failure (P < 0.05). Furthermore, a critical review of recent published case series is presented.

Fluconazole to prevent systemic fungal infections in infants: reviewing the evidence

IN NEONATOLOGY, EVIDENCE-BASED practice (EBP) relies on well-designed, adequately powered trials to guide practitioners. Several large randomized controlled trials (RCTs) have been conducted to explore the use of fluconazole for fungal prophylaxis in premature infants. Despite the findings of these studies, practice varies among units. In a recent survey of members of the American Academy of Pediatrics (AAP), 34 percent of clinicians indicated that they have used antifungal prophylaxis and only 11 percent of clinicians indicated that a written protocol was in place in their NICU. Intravenous (IV) fluconazole (66 percent), oral nystatin (59 percent), and IV amphotericin (21 percent) were the three most commonly used agents among the respondents.1.

Fluconazole prophylaxis in extremely low birth weight infants and neurodevelopmental outcomes and quality of life at 8 to 10 years of age

OBJECTIVE

To examine the long-term effects of fluconazole prophylaxis in extremely low birth weight infants.

STUDY DESIGN

Neurodevelopmental status and quality of life of survivors from a randomized, placebo-controlled trial of fluconazole prophylaxis were evaluated at 8 to 10 years of life using the Vineland Adaptive Behavior Scales-II (VABS-II) and the Child Health Questionnaire Parent-Completed Form 28 (CHQ-PF28), respectively.

RESULTS

VABS-II Domain Scores for the fluconazole-treated (n = 21; 9.1 ± 0.7 years) compared with the placebo group (n = 17; 9.3 ± 0.8 years) were similar for communication [94.6 (±14.8) versus 92.6 (±12.6), P = .65], daily living skills [87.9 (±10.6) versus 87.4 (±9.3), P = .89], socialization [97.2 (±9.2) versus 94.4 (±7.9), P = .31], and motor skills [92.1 (±17.8) versus 95.1 (±14.6), P = .57]. Internalizing and externalizing behaviors and maladaptive behavior index were also similar. The CHQ-PF28 revealed no differences between the two groups regarding quality of life. Survivors were also happy or satisfied with school (90% versus 100%, P = .49), friendships (90% versus 88%, P = 1.00), and life (95% versus 100%, P = 1.00). Self esteem scores were 87.3 ± 15.7 versus 89.7 ± 10.4 (P = .59). There were also no differences between groups regarding emotional difficulties or behavior problems.

CONCLUSIONS

Fluconazole prophylaxis for the prevention of invasive Candida infections is safe in extremely low birth weight infants and does not appear to be associated with any long-term adverse effects on neurodevelopment and quality of life at 8 to 10 years of life.

Nosocomial fungal infections: epidemiology, infection control, and prevention

Fungal infections are an increasing cause of morbidity and mortality in hospitalized patients. This article reviews the current epidemiology of nosocomial fungal infections in adult patients, with an emphasis on invasive candidiasis and aspergillosis. Recently published recommendations and guidelines for the control and prevention of these nosocomial fungal infections are summarized.

Epidemiology of invasive candidiasis

PURPOSE OF REVIEW

This review covers candidaemia in numbers, susceptibility issues, host groups, risk factors and outcome.

RECENT FINDINGS

The incidence of candidaemia has increased over the last decades. Candida glabrata is particularly common in the northern hemisphere and with increasing age whilst the opposite is true for C. parapsilosis, C. glabrata, C. krusei and a number of emerging species are not fully susceptible to azoles. C. parapsilosis and C. guilliermondii are not fully susceptible to echinocandins. Increasing rates of C. parapsilosis have been observed at centres with a high use of echinocandins, and outcome for this species is not superior comparing echinocandins with fluconazole. Acquired azole resistance has recently been described in as many as a third of 19% resistant isolates and echinocandin resistance has emerged and been detected as early as day 12 of echinocandin therapy. ICU stay and abdominal surgery are among the most important risk factors. Outcome is dependent on species involved, timing, dosing and choice of therapy and management of the primary focus of infection. However, host factors are dominating predictors of mortality in recent studies of ICU candidiasis.

SUMMARY

The changing epidemiology highlights the need for close monitoring of local incidence, species distribution and susceptibility in order to optimize therapy and outcome.

Prevalent nosocomial clusters among causative agents for candidemia in Hamilton, Canada

In Canada, the incidence of candidemia, the bloodstream infection caused by Candida species, varied from 1.2-5.1 cases/100,000, representing the third most common type of bloodstream infections in intensive care unit patients. However, the relative contributions of nosocomial transmission in candidemia remain poorly understood. In this study, we investigated the prevalence of nosocomial clusters among the causative agents for candidemia in Hamilton, Ontario, Canada, during a period from January 2005 to February 2009. We genotyped 134 isolates from 125 unrelated patients with candidemia, among which were 87 C. albicans, 20 C. parapsilosis, 11 C. glabrata, 15 C. tropicalis, and one C. krusei. Our PCR fingerprinting analyses using three highly polymorphic primers identified a total of 99 genotypes, with 18 of them shared by 44 independent isolates. Nine pairs of isolates were obtained from the same patients at the same time and each pair had identical fingerprints. Interestingly, all 44 independent strains belonging to each of the shared genotypes were isolated from patients within 3-months stay in the Hamilton hospitals. Both inter- and intra-ward clusters were found, including one that contained strains from intensive care units in two hospitals. Our results indicated that 33% of the patients with candidemia were infected by nosocomial clusters and suggested that measures should be taken in hospitals to prevent nosocomial acquisition of Candida infections.

Strategies to prevent invasive candidal infection in extremely preterm infants

The highest incidence of invasive candidal infection (ICI) occurs in extremely preterm infants (<1000 g birth weight and <or=27 weeks' gestation). In this population, ICI has high mortality, leads to significant neurodevelopmental impairment, and results in increased length of hospital stay and costs. Randomized clinical trials in infants of less than 1000 g birth weight have demonstrated that ICI is decreased 88% by antifungal prophylaxis with fluconazole compared to 54% by nystatin prophylaxis from retrospective studies. Fluconazole is more efficacious than nystatin prophylaxis in infants weighing less than 1000 g, is less expense, requires less frequent dosing (twice weekly intravenous [IV] dosing), and can be given when infants are not feeding. While antifungal prophylaxis is inexpensive, cost-effective, and easy to administer, yet has not been instituted universally despite A-1 evidence from single and multicenter studies demonstrating efficacy and safety. Debate is ongoing over whether empiric therapy or improved infection control practices are superior to prophylaxis, whether prophylaxis should be instituted only in neonatal intensive care units (NICUs) with a relatively high ICI rate, and whether fluconazole prophylaxis is safe or risks emergence of resistance. To date, azole resistance has not emerged with targeted treatment of high-risk infants for the duration of IV catheter use. Empiric therapy for suspected ICI and standardized therapy for candidemia, including central venous catheter removal, may decrease mortality; however, these approaches still risk neurodevelopmental impairment in ICI survivors. Infection control practices have not been subjected to prospective or randomized trials to demonstrate efficacy in reducing fungal infections. Evidence is presented in this article from clinical trials demonstrating efficacy and safety of antifungal prophylaxis in preventing ICI in preterm infants. The greatest impact of antifungal prophylaxis preventing ICI and decreasing Candida-related mortality and neurodevelopmental impairment would be achieved with a universal approach in all NICUs.

Risk factors and prevention of late-onset sepsis in premature infants

Late-onset sepsis in premature infants is a major cause of morbidity, mortality, and increased medical costs. Risk factors include low birth weight, low gestational age, previous antimicrobial exposure, poor hand hygiene, and central venous catheters. Methods studied to prevent late-onset sepsis include early feedings, immune globulin administration, prophylactic antimicrobial administration, and improved hand hygiene. In this review, we will outline the risk factors for development of late-onset sepsis and evidence supporting methods for prevention of late-onset sepsis in premature infants.

Inappropriate empiric antifungal therapy for candidemia in the ICU and hospital resource utilization: a retrospective cohort study

Background

Candida represents the most common cause of invasive fungal disease, and candidal blood stream infections (CBSI) are prevalent in the ICU. Inappropriate antifungal therapy (IAT) is known to increase a patient's risk for death. We hypothesized that in an ICU cohort it would also adversely affect resource utilization.

Methods

We retrospectively identified all patients with candidemia on or before hospital day 14 and requiring an ICU stay at Barnes-Jewish Hospital between 2004 and 2007. Hospital length of stay following culture-proven onset of CBSI (post-CBSI HLOS) was primary and hospital costs secondary endpoints. IAT was defined as treatment delay of ≥24 hours from candidemia onset or inadequate dose of antifungal agent active against the pathogen. We developed generalized linear models (GLM) to assess independent impact of inappropriate therapy on LOS and costs.

Results

Ninety patients met inclusion criteria. IAT was frequent (88.9%). In the IAT group antifungal delay ≥24 hours occurred in 95.0% and inappropriate dosage in 26.3%. Unadjusted hospital mortality was greater among IAT (28.8%) than non-IAT (0%) patients, p = 0.059. Both crude post-CBSI HLOS (18.4 ± 17.0 vs. 10.7 ± 9.4, p = 0.062) and total costs ($66,584 ± $49,120 vs. $33,526 ± $27,244, p = 0.006) were higher in IAT than in non-IAT. In GLMs adjusting for confounders IAT-attributable excess post-CBSI HLOS was 7.7 days (95% CI 0.6-13.5) and attributable total costs were $13,398 (95% CI $1,060-$26,736).

Conclusions

IAT of CBSI, such as delays and incorrect dosing, occurs commonly. In addition to its adverse impact on clinical outcomes, IAT results in substantial prolongation of hospital LOS and increase in hospital costs. Efforts to enhance rates of appropriate therapy for candidemia may improve resource use.

Candida albicans and non-albicans bloodstream infections in adult and pediatric patients: comparison of mortality and costs

We compared length of stay, inpatient costs, and mortality associated with Candida albicans and non-albicans bloodstream infections in adults and children. Compared with adults, children with Candida bloodstream infections had longer lengths of stay (36.7 vs. 20.7 days; P < 0.001) and higher inpatient costs ($133,871 vs. $56,725; P < 0.001) but lower mortality (28.3% vs. 43.5%; P < 0.001).

Case-control studies in pharmacoeconomic research: an overview

The case-control approach has been a mainstay of epidemiological studies, particularly those investigating aetiology. Many articles addressing pharmacoeconomic topics have reported studies purported to be of the case-control type. However, on examination, these were actually standard cohort studies that were misnamed because they compared cases of a particular illness to 'controls' without the illness. The actual case-control design involves a series of cases with the outcome of interest. In pharmacoeconomic applications, the outcome of interest would typically be high cost, or hospitalization, or return to full quality of life. The illness does not define cases, but rather is actually the 'exposure'. The 'controls' must be a sample of the study base, not subjects without the illness. In this article, we review the features of a proper case-control study and contrast them with those of the more common cohort study. Confusing the control series of a cohort study with the 'controls' in a case-control study leads to serious problems with understanding the research, its strengths and drawbacks (e.g. confounding concerns), and interpretation of the findings. Although the case-control design has so far been used little to address pharmacoeconomic questions, it can be very efficient in certain situations, particularly when obtaining data on all subjects is burdensome or when conditions provide a ready case series but not the rest of the subjects.

Pediatric antifungal utilization: new drugs, new trends

BACKGROUND

The frequency and severity of invasive fungal infections in immunocompromised patients has increased steadily over the last 2 decades. In response to the increased incidence and high mortality rates, novel antifungal agents have been developed to expand the breadth and effectiveness of treatment options available to clinicians. Despite these therapeutic advances, the impact of the availability of new antifungal agents on pediatric practice is unknown.

METHODS

A retrospective cohort study was conducted using the Pediatric Health Information System database to describe the changes in pediatric antifungal therapy at 25 freestanding United States children's hospitals from 2000 to 2006. All pediatric inpatients who received a charge for one or more of the following agents were included in the analysis: conventional amphotericin B (AMB), lipid amphotericin B, fluconazole, itraconazole, voriconazole, flucytosine, caspofungin, and micafungin. Underlying conditions and fungal infection status were ascertained.

RESULTS

A total of 62,842 patients received antifungal therapy, with prescriptions significantly increasing during the 7-year study period (P = 0.03). The most commonly prescribed antifungal agent was fluconazole (76%), followed by amphotericin preparations (26%). Prescription of AMB steadily decreased from 2000 to 2006 (P = 0.02). Prescription of voriconazole steadily increased during the study period and replaced AMB for the treatment of aspergillosis. The echinocandins steadily increased in prescription for treatment of fungal infections, particularly in disseminated/systemic candidiasis.

CONCLUSIONS

We found that the number of pediatric inpatients requiring antifungal therapy has increased significantly and the choice of treatment has changed dramatically with the introduction of newer antifungal agents.

Molecular epidemiology of candidemia: evidence of clusters of smoldering nosocomial infections

BACKGROUND

Invasive fungal infections pose a serious threat to hospitalized patients worldwide. In particular, the prevalence of clusters of nosocomial infection among patients with candidemia remains unknown. The aim of this study was to investigate the molecular epidemiology of candidemia in a nationwide setting in Iceland during a 16-year period.

METHODS

The genotypes of all available fungal bloodstream isolates during 1991-2006 (n = 219) were determined by polymerase chain reaction fingerprinting with use of 4 separate primers. Clusters were defined as isolation of > or =2 strains with genotypes that had > or =90% relatedness in the same hospital within a period of 90 days.

RESULTS

Candida albicans represented 61.6% of isolates, followed by Candida glabrata (13.7%), Candida tropicalis (9.1%), and Candida parapsilosis (8.7%). Polymerase chain reaction fingerprinting revealed 35 clones of C. albicans, 10 clones of C. glabrata, 7 clones of C. tropicalis, 4 clones of C. parapsilosis, and 5 clones of Candida dubliniensis. Overall, 18.7%-39.9% of all infections were part of nosocomial clusters, most commonly caused by C. albicans, C. parapsilosis, and C. tropicalis. Most clusters involved 2 cases and disproportionately affected patients in adult and neonatal intensive care units (P = .045). The 7-day (16%) and 30-day (32%) case-fatality rates among cluster-associated cases did not differ statistically significantly from those for sporadic nosocomial infections. None of the clusters were identified by the hospital surveillance team.

CONCLUSIONS

In an unselected patient population, as many as one-third of all cases of candidemia may be attributable to nosocomial clusters. The risk is dependent on hospital wards and patient populations; it is highest in intensive care units. Small clusters are not identified by routine hospital surveillance.

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.

Hospital-acquired infections in the NICU: epidemiology for the new millennium

Nosocomial infections are an important cause of morbidity and mortality in the preterm neonate. Extrinsic and intrinsic risk factors make the preterm neonate particularly susceptible to infection. This review focuses on two major pathogens that cause nosocomial infection, Candida and methicillin-resistant Staphylococcus aureus. The difficult diagnosis of meningitis in the neonate also is discussed.