Strategies for prevention of neonatal invasive candidiasis

Invasive fungal infections in neonates: a review

Invasive fungal infections remain the leading causes of morbidity and mortality in neonates, especially preterm and very low birth weight infants. Most invasive fungal infections are due to Candida or Aspergillus species, and other fungi are increasingly reported and described. Appropriate identification and treatment are required to augment activity and reduce the toxicity of antifungal drugs. Successful use of antifungals in the vulnerable neonatal population is important for both prevention and treatment of infection. Strategies for prevention, including prophylactic antifungal therapy as well as reducing exposure to modifiable risk factors, like limiting antibiotic exposure, discontinuation of central catheters, and hand hygiene are key techniques to prevent and decrease rates of invasive fungal infections. In conclusion, this is a review of the most common causes, prevention strategies, prophylaxis, and treatment of invasive fungal infections in neonates.

Can we back off using antibiotics in the NICU?

Antibiotics are extensively and inconsistently prescribed in neonatal ICUs, and usage does not correlate with rates of culture positive sepsis. There is mounting data describing the short and long-term adverse effects associated with antibiotic overuse in neonates, including the increased burden of multi-drug resistant organisms. Currently there is considerable variation in antibiotic prescribing practice among neonatologists. Applying the practice of antibiotic stewardship in the NICU is crucial for standardizing antibiotic use and improving outcomes in this population. Several approaches have been proposed to identify neonatal sepsis, with the hope of reducing antibiotic utilization. These strategies all have their limitations, and often include laboratory testing and treatment of well-appearing, non-septic, infants. A conservative "watch and wait" algorithm is suggested as an alternative method for when to initiate antibiotics. This observational approach relies on availability of trained personnel able to examine infants at specified intervals, without delaying antibiotics, should signs of sepsis arise.

Review of Fluconazole Treatment and Prophylaxis for Invasive Candidiasis in Neonates

Invasive candidiasis accounts for approximately 10% of nosocomial infections in preterm infants, with an incidence of 1% to 4% among neonatal intensive care unit (NICU) admissions and a mortality as high as 20% to 30%. These outcomes warrant improved treatment and prevention strategies for infants at highest risk. The Infectious Diseases Society of America provides guidelines on antifungal medications for the prophylaxis and treatment of candidiasis in NICUs; however, there are still variations in practice on the use of fluconazole for prophylaxis and treatment of invasive candidiasis. This review provides specific information regarding fluconazole activity, pharmacokinetics, and a literature evaluation of dosing strategies and comparisons to other treatments in the neonatal population.

Antifungal Drugs in Newborns and Children

Invasive fungal infections are a significant cause of morbidity and mortality in infants and children. Early diagnosis is critical, and treatment with the appropriate drug and dose should be initiated promptly. Although an increasing number of studies have examined dosing of antifungals in this population, pediatric safety and efficacy data are lacking.

Integrated measures for prevention of invasive Candida infections in preterm infants in a Chinese neonatal intensive care unit

BACKGROUND

The increasing incidence of invasive Candida infections (ICIs) in preterm infants in the neonatal intensive care unit (NICU) of Xinhua Hospital aroused our concern. We undertook a retrospective study to evaluate the efficacy of different preventive measures for ICI in preterm infants.

METHODS

Preterm infants with gestational age (GA) <33 weeks admitted between 2010 and 2013 were divided into 3 groups according to the preventive measures applied in different periods: the control group (CG), fluconazole group (FG), and integrated measures group (IMG). We analyzed the incidence of ICI and distribution of fungal pathogens in these 3 groups, and also evaluated the efficiency of various measures in preventing ICIs in preterm infants.

RESULTS

The study sample comprised 261 preterm infants born at <33 weeks GA, including 94 in the CG, 99 in the FG, and 68 in the IMG. The differences among the groups were not significant at baseline. ICI developed in 41 of the 261 infants (15.7%). The incidence of ICI varied significantly among the groups: 22.3% in the CG (21/94), 18.2% in the FG (18/99), and only 2.9% in the IMG (2/68) (P = .003). ICI was less frequent in the IMG compared with the CG (P <.001) and the FG (P = .003).

CONCLUSIONS

The integrated measures approach is meaningful for the prevention of ICIs in preterm infants in NICUs with many patients but inadequate medical resources in some developing countries.

Antibiotics and Antifungals in Neonatal Intensive Care Units: A Review

The incidence of infections is higher in the neonatal period than at any time of life. The basic treatment of infants with infection has not changed substantially over the last years. Antibiotics (with or without supportive care) are one of the most valuable resources in managing sick newborn babies. Early-onset (ascending or transplacental) or late-onset (hospital acquired) infections present different chronology, epidemiology, physiology and outcome. Some classes of antibiotics are frequently used in the neonatal period: penicillins, cephalosporins, aminoglycosides, glycopeptides, monobactams, carbapenems. Other classes of antibiotics (chloramphenicol, cotrimoxazole, macrolides, clindamycin, rifampicin and metronidazole) are rarely used. Due to emergence of resistant bacterial strains in Neonatal Intensive Care Units (NICU), other classes of antibiotics such as quinolones and linezolid will probably increase their therapeutic role in the future. Although new formulations have been developed for treatment of fungal infections in infants, amphotericin B remains first-line treatment for systemic Candida infection. Prophylactic antibiotic therapy is almost always undesirable. Challenges from pathogens and antibiotic resistance in the NICU may warrant modification of traditional antibiotic regimens. Knowledge of local flora and practical application of different antibiotic characteristics are key to an effective and safe utilization of antibiotics and antifungals in critical newborns admitted to the NICU, and especially in very low birth weight infants.

Neonatal fungal infections: when to treat?

Candida infections are a major cause of morbidity and mortality in neonatal intensive care units. Mortality following Candida bloodstream infections is as high as 40%, and neurodevelopmental impairment is common among survivors. Because invasive fungal infections are common and extremely difficult to diagnose, empirical treatment with antifungal therapy should be considered in high-risk, low-birth-weight infants who fail to quickly respond to empirical antibacterial treatment. Risk factors to consider when deciding to administer empirical antifungal therapy include: prior exposure to third-generation cephalosporins, extreme prematurity, and presence of central venous catheters.

Strategies for the prevention of neonatal candidiasis

Invasive fungal infections represent the third-leading cause of late-onset sepsis in very-low-birth-weight infants (VLBWI) and have a high rate of infection-associated mortality. The infants at high risk for fungal sepsis are VLBWI with presence of additional risk factors that contribute to increased colonization and concentration of fungal organisms. Colonization with Candida spp. in neonates is secondary to either maternal vertical transmission or nosocomial acquisition in the nursery. Multiple sites may become colonized and a direct correlation between fungal colonization and subsequent progression to invasive candidemia was determined. Randomized, single and multiple-center, placebo-controlled trials found intravenous fluconazole prophylaxis to be effective in decreasing fungal colonization and sepsis for at-risk preterm infants <1500 g birth weight. The prophylactic use of fluconazole was found to be safe with no significant development of fungal resistance. Fluconazole prophylaxis administered to preterm neonates with birth weight <1000 g and/or 27 weeks' gestation or less has the potential of reducing and potentially eliminating invasive fungal infections and Candida-related mortality.

Clinical practice: Obstructive renal candidiasis in infancy

Renal candidiasis is an increasingly common condition affecting predominantly premature infants receiving neonatal intensive care or term infants with urogenital tract anomalies. Multiple risk factors are usually present. Although rare, some infants develop an obstructive uropathy due to fungal balls, and this requires prompt detection and intervention to preserve kidney function. The management of obstructive renal bezoars is challenging and not well summarised in the past. This is mainly due to scarce literature confined to case reports or case series only. This review clarifies various definitions used in relation to renal candidiasis and identifies infants particularly at risk of obstruction. Clinical presentation, diagnosis and the role of imaging are discussed. A summary of the recent literature is provided to outline the range of existing treatment options available with published drug dosages and mode of delivery used. No single approach is successful in all cases and clinicians need to be aware of the different options available: apart from adequate urinary drainage and use of systemic +/- local antifungal agents, additional treatment with fibrinolytic agents and/or endoscopic or open surgical removal may be required. A new simplified algorithm for use in management is proposed. We hope this review will help clinicians in their management of patients presenting with this complex and challenging diagnosis.

Recent Advances in the Detection of Neonatal Candidiasis

Neonatal candidiasis is serious and often fatal. Blood culture, the standard for diagnosis, has a sensitivity of 50% or less, and isolate speciation and susceptibility takes several days. This review explores recent advances in Candida detection using various diagnostic strategies.

Invasive candidiasis in pediatric intensive care units

Candidemia and disseminated candidiasis are major causes of morbidity and mortality in hospitalized patients especially in the intensive care units (ICU). The incidence of invasive candidasis is on a steady rise because of increasing use of multiple antibiotics and invasive procedures carried out in the ICUs. Worldwide there is a shifting trend from C. albicans towards non albicans species, with an associated increase in mortality and antifungal resistance. In the ICU a predisposed host in one who is on broad spectrum antibiotics, parenteral nutrition, and central venous catheters. There are no pathognomonic signs or symptoms. The clinical clues are: unexplained fever or signs of severe sepsis or septic shock while on antibiotics, multiple, non-tender, nodular erythematous cutaneous lesions. The spectrum of infection with candida species range from superficial candidiasis of the skin and mucosa to more serious life threatening infections. Treatment of candidiasis involves removal of the most likely source of infection and drug therapy to speed up the clearance of infection. Amphotericin B remains the initial drug of first choice in hemodynamically unstable critically ill children in the wake of increasing resistance to azoles. Evaluation of newer antifungal agents and precise role of prophylactic therapy in ICU patients is needed.

The role of Candida surveillance cultures for identification of a preterm subpopulation at highest risk for invasive fungal infection

Candida surveillance cultures were obtained from 51 neonatal intensive care unit patients. Sixteen infants showing positive cultures developed subsequent Candida infection, whereas it did not occur for the 35 infants with negative cultures. Fifteen of 16 infants (<1000 g) had <27 weeks of gestational age. Antifungal treatment was started at the time colonization was detected; only 1 infant died of Candida infection.

Routine use of fluconazole prophylaxis in a neonatal intensive care unit does not select natively fluconazole-resistant Candida subspecies

BACKGROUND

We have previously demonstrated efficacy against fungal colonization and infection of fluconazole prophylaxis that was routinely administered since 2001 in our ICU for preterm infants <1500 g at birth (VLBW). With prolonged use, concerns exist for the emergence of acquired fungal resistance and of Candida subspecies that are natively fluconazole-resistant (NFR), mostly Candida glabrata and Candida krusei.

METHODS

We evaluated retrospectively all clinical and surveillance fungal isolates obtained from VLBW infants in our NICU during a 10-year period (1997-2006). Each fungal isolate was speciated, infants colonized or infected with NFR-Candida spp were identified and the incidence rates of colonization and infection by these fungal species were calculated. A comparison was made of the 6-year (2001-2006) prophylaxis period with the 4-year (1997-2000) preprophylaxis period.

RESULTS

Overall, colonization by NFR-Candida spp ranged between 2.8% and 6.6% of VLBW infants yearly admitted, without any increasing trend during the study period. There were 18 of 434 (4.1%) neonates colonized by these species. Five episodes of systemic fungal infections caused by NFR-Candida spp occurred (incidence rate, 1.1%). No significant differences were detected when compared with the preprophylaxis period, when 11 of 295 infants (3.7%) were colonized by NFR-Candida spp and 4 episodes of infection occurred (1.4%) (P = 0.84 and 0.76, respectively).

CONCLUSIONS

Fluconazole prophylaxis administered to VLBW neonates in 4- to 6-week courses after birth does not lead to the emergence of natively fluconazole-resistant Candida spp.

Chitotriosidase activity in human milk from mothers of premature and full-term infants during the first month of lactation

OBJECTIVE

The objectives of the present study were to measure the activity of chitotriosidase (ChT) in human milk, to record changes in enzyme activity over time and to determine whether there are differences in activity between the milk of mothers of full-term (FT) and premature (PT) infants.

PATIENTS AND METHODS

Three samples were collected from each of 28 mothers (26.9+/-4.3 years of age; mean+/-SD) of FT infants (gestational age, 39.1+/-0.9 weeks; birth weight, 3384.8+/-369.8 g.; median, 3485 g) and 28 mothers (26.6+/-3.6 years of age) of healthy PT infants (gestational age, 30.5+/-3.1 weeks; birth weight, 1400+/-492.9 g.; median, 1285 g). Samples were collected at 3, 7 and 28th days after delivery. ChT activity was estimated using the fluorimetric method. ChT activities were calculated and expressed as nanomoles per milliliter per hour.

RESULTS

ChT activity was higher in the PT group than in the FT group at day 3 [170.2 (14.0-294.8) vs. 81.7 (6.9-306.3) nmol/mL/h], day 7 [31.6 (0.0-166.7) vs. 17.2 (0.0-214.1) nmol/mL/h] and day 28 [5.5 (0.0-64.9) vs. 3.4 (0.0-51.6) nmol/mL/h].

CONCLUSION

The higher ChT activity in milk of mothers of PT infants than those of FT infants suggests the presence of activated macrophages as its main source. ChT is well known to play a role in defense against fungi and have the ability to degrade both colloidal chitin and chitin in the cell wall of Candida albicans. Thus, our findings may indicate that infants have a natural advantage for protection from fungus infections when they are fed by their mothers' milk.

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.

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]).

Neonatal coinfection model of coagulase-negative Staphylococcus (Staphylococcus epidermidis) and Candida albicans: fluconazole prophylaxis enhances survival and growth

Coagulase-negative staphylococci (CoNS) and Candida are among the most common causes of single infections and coinfections in neonates after 72 h of age. In neonates, coinfection increases the rate of mortality threefold and results in significantly greater morbidity compared to those that result from single infections. In an effort to better understand this phenomenon, we developed the first neonatal animal model of coinfection (with CoNS and Candida) and evaluated its effects on mortality and morbidity and the impact of antifungal prophylaxis with fluconazole. Neonatal Wistar rats were infected with Candida albicans and/or Staphylococcus epidermidis with doses of 2x10(8) and 2x10(6) CFU subcutaneously in different combinations and were monitored for mortality, weight gain, and bacteremia. The in vitro sensitivity of C. albicans to fluconazole was evaluated and the MIC was determined. A subset of rats in these experiments received fluconazole at 10 mg/kg of body weight/dose intraperitoneally starting 24 h before infection for 4 days, and the serum trough levels of fluconazole were measured. Coinfection in the suckling rat significantly increased the rate of mortality compared to that after infection with a single species (P<0.001) and resulted in deaths even at sublethal doses. Coinfection also impaired weight gain significantly in severely infected pups compared to that achieved after infection with a single species (P<0.001). Fluconazole prophylaxis significantly reduced mortality by 30% in the Candida group and 36% in the coinfection group and improved weight gain in this neonatal model of coinfection (P<0.001). We developed a neonatal model of coinfection with Candida and CoNS, observed significantly greater mortality and morbidity with coinfection, and found that fluconazole prophylaxis significantly reduced the rates of both mortality and morbidity. Further research on neonatal coinfection is urgently needed to improve clinical outcomes.

[Invasive fungal dermatitis in extremely premature newborns: a specific clinical form of systemic candidiasis]

BACKGROUND

Fungal agents, chiefly Candida albicans, are the cause of rising morbidity and mortality in newborn infants weighing less than 1500 g. We studied the particular cutaneous effects during the course of these infections.

PATIENTS AND METHODS

This was a retrospective 3-year study in premature infants weighing less than 1500 g and hospitalized in the neonatal department of the Lille University Teaching Hospital. The patients included in the study presented sepsis with isolation of Candida in blood and/or urine culture.

RESULTS

Twelve infants were included (1.8%). The risk factors seen are those described in literature (broad-spectrum antibiotics, prolonged mechanical ventilation and parenteral nutrition, corticosteroids and central venous catheters). Infection occurred early (mean: D12) and affected extremely premature infants (mean: 25 weeks' amenorrhea) of low birth weight (mean: 758 g) generally born by vaginal delivery (9 of 12 infants). The sole fungal agent isolated was Candida albicans. In 10 of the 12 patients, a characteristic skin disorder was observed (erythema with erosion and desquamation). In 10 of the 12 patients, too, Candida was isolated from skin and/or mucosal samples.

DISCUSSION

Although it is now universally accepted that antifungal treatment should be initiated without delay for candidemia in septic newborn infants at risk, diagnosis of systemic candidiasis remains delicate. However, a specific pattern of skin involvement is very commonly seen that is atypical for candidiasis, but which in addition to its diagnostic value indicates early colonization with Candida (first 2 weeks of life). In this setting of immaturity of the skin and immune system, colonization and proliferation in skin and/or mucosa appear to constitute the first stage of systemic infection and we may speak of invasive cutaneous-mucosal candidiasis in extremely premature infants and initiate treatment designed to prevent the disease becoming systemic..

Epidemiology of Community‐Onset Candidemia in Connecticut and Maryland

BACKGROUND

Almost one-third of patients with bloodstream infections with Candida species (candidemia) have onset of disease that occurs outside of the hospital or < or = 2 days after hospital admission (i.e., community-onset candidemia). We compared the characteristics of patients who developed candidemia by the timing of onset of infection.

METHODS

Incident episodes of candidemia were identified through active, population-based surveillance in Connecticut and in Baltimore and Baltimore County, Maryland, during 1 October 1998-30 September 2000. The molecular subtypes of a sample of 45 Candida parapsilosis isolates were evaluated using Southern blots hybridized with the complex probe Cp3-13.

RESULTS

Overall, 356 (31%) of the 1143 incident episodes of candidemia were classified as community-onset disease (occurring < or = 2 days after hospital admission), and 132 (37%) were caused by Candida albicans, 89 (25%) were caused by Candida glabrata, 57 (16%) were caused by C. parapsilosis, and 53 (15%) were caused by Candida tropicalis. Community-onset disease was less likely to be associated with concurrent immunosuppressive therapy, recent surgery, or use of a central venous catheter, compared with inpatient disease. Among patients with community-onset disease, the median time from blood culture to initiation of antifungal treatment was 2.7 days, the 30-day case-fatality rate was 26%, and 262 patients (75%) had been hospitalized at least once in the previous 3 months. Although there were few differences between patients with very recent hospitalization (in the previous 1 month), less recent hospitalization (previous 1-3 months), and no documented past hospitalization, C. parapsilosis was more frequently associated with community-onset disease as hospitalization became more distant. C. parapsilosis strains tended to be unique to the patient, with little similarity found between strain types, on the basis of epidemiologic classification of patients.

CONCLUSION

We report that community-onset candidemia is common and occurs in patients with extensive contact with the health care system. Disease caused by C. parapsilosis tends to involve unique strains.

Invasive fungal infection in very low birthweight infants: national prospective surveillance study

OBJECTIVE

To describe the epidemiology of invasive fungal infection in very low birthweight (VLBW: <1500 g) infants in the United Kingdom.

DESIGN

National prospective surveillance study between February 2003 and February 2004 using the British Paediatric Surveillance Unit reporting system reconciled with cases identified through routine laboratory reporting to the Health Protection Agency (England, Wales, and Northern Ireland), the Scottish Centre for Infection and Environmental Health, and the UK Mycology Reference Laboratory.

RESULTS

Ninety four confirmed cases of invasive fungal infection were identified during the surveillance period giving an incidence of estimated annual incidence of 10.0 (95% confidence interval (CI) 8.0 to 12.0) cases per 1000 VLBW live births. Eighty one (86%) of the infants were of extremely low birth weight (ELBW: <1000 g), incidence 21.1 (95% CI 16.5 to 25.7) per 1000 ELBW live births. Candida species, predominantly C albicans and C parapsilosis, were isolated in 93% of cases. Most organisms were isolated from the bloodstream and urinary tract. Death occurred in 41% of the infected infants before 37 weeks postconceptional age.

CONCLUSIONS

The incidence of invasive fungal infection in VLBW and ELBW infants in the United Kingdom is lower than reported in previous studies from tertiary centres in North America and elsewhere. The associated late neonatal and post-neonatal death rates are substantially higher than expected in infants without invasive fungal infection. These data may inform decisions about the evaluation and use of antifungal infection control strategies.

Invasive Candida infections in the neonate

Advances in medical therapy have increased premature infant survival. A rise in Candida infections in neonatal intensive care units (NICUs) has followed. Once considered a contaminant, Candida is now recognized as a major cause of mortality and morbidity within these units. We will examine what is known about the epidemiology, risk factors and end-organ involvement of Candida infections with a focus on invasive disease. In addition, diagnostic alternatives to traditional blood culture, experience with antifungal agents for prophylaxis and therapeutic options, including newer antifungal agents, will be presented.

Neonatal candidiasis: prophylaxis and treatment

The incidence of candidiasis has risen in neonatal intensive care units as advances in medical therapy have allowed for increased survival of extremely preterm neonates. The mortality of candidiasis has been reported to be 20% by several multi-centre studies. Definitive guidance for prophylaxis and treatment is hindered by lack of large, multi-centre, randomised controlled trials. Systemic prophylaxis is currently not recommended for any neonatal population, and amphotericin B deoxycholate continues to be used as first-line therapy for the treatment of invasive disease.

Determining risk factors for candidemia among newborn infants from population-based surveillance: Baltimore, Maryland, 1998-2000

BACKGROUND

Our objective was to determine risks factors for late onset candidemia, independent of birth weight, in newborn infants.

METHODS

We performed a matched case-control study. Cases were identified through active, population-based surveillance for candidemia, conducted in Baltimore City and County during 1998-2000, and were defined as the incident isolation of any Candida species from the bloodstream of an infant 3 months old or younger. Four controls, matched by age, hospital, birth weight category, hospital stay and admission date, were selected for each case. Potential risk factors included clinical, demographic and maternal prenatal data.

RESULTS

Of the 35 cases, 19 (54%) infections were with Candida albicans, 9 (26%) were with Candida parapsilosis and 5 (14%) were with Candida glabrata. Cases had a median birth weight of 680 g (range, 430-3200 g); median gestational ages of cases and controls were 25 and 27 weeks, respectively. Compared with controls, cases had significant higher mortality (20% versus 4%; P = 0.004). No maternal factors were associated with increased risk of disease; cases were as likely as controls to be of black race. Multivariable conditional logistic regression analysis revealed that gestational age younger than 26 weeks [adjusted odds ratio, 6.5; 95% confidence interval (95% CI), 1.3-32], vaginal delivery (adjusted odds ratio, 4.3; 95% CI 1.3-14.2) and abdominal surgery (adjusted odds ratio, 10.9; 95% CI 1.9-62) were independently associated with increased risk of candidemia.

CONCLUSIONS

Independent of birth weight, infants born at <26 weeks or those who have had abdominal surgery are at a significantly increased risk of candidemia. This study helps define a subgroup of preterm infants at high risk of developing bloodstream infections with Candida species.

Fungal infection in the very low birthweight infant

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

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

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

Novel approaches to antifungal prophylaxis

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