[Yeast count in urine. Review of the literature and preliminary results of a multicenter prospective study carried out in 15 hospital centers]

Urine Sediment Findings and the Immune Response to Pathologies in Fungal Urinary Tract Infections Caused by Candida spp

Fungi are pathogenic agents that can also cause disseminated infections involving the kidneys. Besides Candida, other agents like Cryptococcus spp. can cause urinary tract infection (UTI), as well as other non-yeast fungi, especially among immunocompromised patients. The detection and identification of fungi in urine samples (by microscopy and culture) plays an essential role in the diagnosis of fungal UTI. However, variable cutoff definitions and unreliable culture techniques may skew analysis of the incidence and outcome of candiduria. The sediment analysis plays a key role in the identification of fungal UTI because both yeasts and pseudohyphae are easily identified and can be used as a clinical sign of fungal UTI but should not be overinterpreted. Indeed, urine markers of the immune response (leukocytes), urine barriers of tissue protection (epithelial cells), and urine markers of kidney disease (urinary casts) can be found in urine samples. This work explores the manifestations associated with the fungal UTI from the urinalysis perspective, namely the urinary findings and clinical picture of patients with fungal UTI caused by Candida spp., aspects associated with the immune response, and the future perspectives of urinalysis in the diagnosis of this clinical condition.

Approach of clinicians to candiduria and related outcome in the elderly

OBJECTIVE

Candiduria is increasingly frequent in hospitalized debilitated patients. We aimed to evaluate the approach of clinicians to candiduria in the oldest old, and its effect on clearance and mortality.

MATERIAL AND METHODS

An observational study without intervention was carried out during 2012 and 2013 in three Spanish hospitals over patients with nosocomial candiduria aged 80 and over. Following a diagnostic algorithm, we assessed the appropriateness of antifungal therapy and analyzed the impact of the clinical approach (antifungal therapy, antibiotics discontinuation and catheter removal or replacement) on the outcome (mortality at 60 days and resolution, persistence or recurrence of candiduria).

RESULTS

Hundred and forty eight patients were included. Symptomatology was attributable to candiduria in 31 instances and 19 asymptomatic patients were found at risk of developing candidemia. In response to culture-results, 77 (52%) of patients were treated with antifungals, mainly fluconazole (97.4%). The use of pharmacological therapy was appropriate (P<0.05) but subtherapeutical doses of fluconazole were widely used and follow-up samples were scarcely submitted. At 60 days of diagnosis the mortality was high (29.7%). The replacement or removal of the catheter resulted in a decrease in mortality and the use of antifungal treatment was associated with recurrence (P<0.05).

CONCLUSIONS

In the absence of clinical practice guidelines with enough evidence, our study suggests that catheter removal should always be tried in the elderly with candiduria, since it reduces the mortality. The repetition of culture should help to better characterize the asymptomatic episodes, which are predominant, and to reduce the use of antifungals.

Candiduria: Evidence-based approach to management, are we there yet?

Candiduria is considered one of the most controversial issues in patient management. Neither the diagnosis nor the optimal treatment options are standardized. This is further complicated by lack of defined laboratory criteria for diagnosis as most of the studies were set for bacterial rather than fungal urinary tract infection (UTI). Furthermore, since Candida species is a known commensal of the genitourinary tract its presence in the urine sample adds ambiguity to making a definitive diagnosis of candidal UTI. Guidelines for diagnosis and management of candiduria have changed considerably over the past decades. In 1960s, the condition was believed to be benign with no intervention required. However, over the years new dimensions were added to address the issues associated with candiduria until the latest Infectious Diseases Association of America (IDSA) guidelines were published in 2009, which indicated that there was an increase in the incidence of candiduria caused by more resistant non-Candida albicans species. Further complicating the issue is the observation that candiduria may be the only indicator of a more serious invasive candidiasis, especially in immunocompromised patients. Long-term urinary catheterization is considered to be the most significant risk factor for candiduria followed by antibiotic use and diabetes. Strategies for management are based on the evaluation of candiduria in the context of the clinical setting to determine its relevance and make an appropriate decision about the need for antifungal therapy. Fluconazole is the main drug used for its efficacy and least complications. Other options include bladder irrigation with amphotericin B, flucytosine or parenteral amphotericin B. Since azoles other than fluconazole and all echinocandins are poorly excreted in urine they have been found to be less effective in candiduric patients.

Candida colonization index and subsequent infection in critically ill surgical patients: 20 years later

Introduction

For decades, clinicians dealing with immunocompromised and critically ill patients have perceived a link between Candida colonization and subsequent infection. However, the pathophysiological progression from colonization to infection was clearly established only through the formal description of the colonization index (CI) in critically ill patients. Unfortunately, the literature reflects intense confusion about the pathophysiology of invasive candidiasis and specific associated risk factors.

Methods

We review the contribution of the CI in the field of Candida infection and its development in the 20 years following its original description in 1994. The development of the CI enabled an improved understanding of the pathogenesis of invasive candidiasis and the use of targeted empirical antifungal therapy in subgroups of patients at increased risk for infection.

Results

The recognition of specific characteristics among underlying conditions, such as neutropenia, solid organ transplantation, and surgical and nonsurgical critical illness, has enabled the description of distinct epidemiological patterns in the development of invasive candidiasis.

Conclusions

Despite its limited bedside practicality and before confirmation of potentially more accurate predictors, such as specific biomarkers, the CI remains an important way to characterize the dynamics of colonization, which increases early in patients who develop invasive candidiasis.

Diagnosis of invasive candidiasis in the ICU

Invasive candidiasis ranges from 5 to 10 cases per 1,000 ICU admissions and represents 5% to 10% of all ICU-acquired infections, with an overall mortality comparable to that of severe sepsis/septic shock. A large majority of them are due to Candida albicans, but the proportion of strains with decreased sensitivity or resistance to fluconazole is increasingly reported. A high proportion of ICU patients become colonized, but only 5% to 30% of them develop an invasive infection. Progressive colonization and major abdominal surgery are common risk factors, but invasive candidiasis is difficult to predict and early diagnosis remains a major challenge. Indeed, blood cultures are positive in a minority of cases and often late in the course of infection. New nonculture-based laboratory techniques may contribute to early diagnosis and management of invasive candidiasis. Both serologic (mannan, antimannan, and betaglucan) and molecular (Candida-specific PCR in blood and serum) have been applied as serial screening procedures in high-risk patients. However, although reasonably sensitive and specific, these techniques are largely investigational and their clinical usefulness remains to be established. Identification of patients susceptible to benefit from empirical antifungal treatment remains challenging, but it is mandatory to avoid antifungal overuse in critically ill patients. Growing evidence suggests that monitoring the dynamic of Candida colonization in surgical patients and prediction rules based on combined risk factors may be used to identify ICU patients at high risk of invasive candidiasis susceptible to benefit from prophylaxis or preemptive antifungal treatment.

Candida infections of the genitourinary tract

All humans are colonized with Candida species, mostly Candida albicans, yet some develop diseases due to Candida, among which genitourinary manifestations are extremely common. The forms of genitourinary candidiasis are distinct from each other and affect different populations. While vulvovaginal candidiasis affects mostly healthy women, candiduria occurs typically in elderly, hospitalized, or immunocompromised patients and in neonates. Despite its high incidence and clinical relevance, genitourinary candidiasis is understudied, and therefore, important questions about pathogenesis and treatment guidelines remain to be resolved. In this review, we summarize the current knowledge about genitourinary candidiasis.

Candiduria in intensive care units: association with heavy colonization and candidaemia

Candiduria is increasingly detected in intensive care unit (ICU) patients and often coexists with candidal colonization at other anatomical sites. Studies involving surgical and medical ICU patients have consistently reported a relationship between candiduria and heavy colonization. This suggests that candiduria could be considered as a marker for heavy colonization. Risk factors that predispose to heavy colonization are generally similar to those predisposing to candidaemia. Candiduria in ICU patients is characterized by a high mortality, largely through a significant relationship with candidaemia, which in some patients may reach 50%. Therapeutic interventions should be strongly considered in the critically ill patient who presents with candiduria and concurrent clinical risk factors predisposing to dissemination.

[Management of fungal urinary tract infections]

Fungal urinary tract infections (funguria) are rare in community medicine, but common in hospitals where 10 to 30% of urine cultures isolate Candida species. Clinical features vary from asymptomatic urinary tract colonization (the most common situation) to cystitis, pyelonephritis, or even severe sepsis with fungemia. The pathologic nature of funguria is closely related to host factors, and management depends mainly on the patient's underlying health status. Microbiological diagnosis of funguria is usually based on a fungal concentration of more than 10(3)/mm(3) in urine. No cutoff point has been defined for leukocyte concentration in urine. Candida albicans is the most commonly isolated species, but previous antifungal treatment and previous hospitalization affect both species and susceptibility to antifungal agents. Treatment is recommended only when funguria is symptomatic or in cases of fungal colonization when host factors increase the risk of fungemia. The antifungal agents used for funguria are mainly fluconazole and amphotericin B deoxycholate, because other drugs have extremely low concentrations in urine. Primary and secondary preventions are essential. The reduction of risk factors requires removing urinary catheters, limiting antibiotic treatment, and optimizing diabetes mellitus treatment.

[Candiduria in intensive care unit: significance and value of yeast numeration in urine]

JUSTIFICATION

Candiduria is increasingly frequent among patients admitted to intensive care units but its significance remains unclear.

OBJECTIVES

Search for eventual correlation between quantitative candiduria and known risk factors for invasive candidiasis.

STUDY DESIGN

Prospective.

PATIENTS AND METHODS

A four-month study was conducted in 162 patients hospitalized in the intensive care unit for more than 72 hours. All patients underwent a weekly research of candiduria added to sampling from different body sites to determine the Pittet Candida colonization index.

RESULTS

Candiduria has been proved in 56 cases (34%). It was superior or equal to 10(4) UFC/ml among 28 patients (50%). Candida tropicalis, Candida glabrata and Candida albicans has been isolated in 41, 22 and 20% respectively. All patients had at least one major and two minor risk factors for Candida infection. Six patients (10%) developed invasive candidiasis. The global mortality rate was at 52%. Pittet colonization index was significantly different between patients with candiduria and those with invasive candidiasis (p=0.01). There was a statistically significant correlation between candiduria superior or equal to 10(4) UFC/ml and Pittet colonization index superior or equal to 0.5 (p=0.01).

CONCLUSION

Candiduria superior or equal to 10(4) UFC/ml associated with risk factors may predict invasive candidiasis in critically ill patients.

Epidemiology of Candida species infections in critically ill non-immunosuppressed patients

A substantial proportion of patients become colonised with Candida spp during hospital stay, but only few subsequently develop severe infection. Clinical signs of severe infection manifest early but lack specificity until late in the course of the disease, thus representing a particular challenge for diagnosis. Mostly nosocomial, invasive candidiasis occurs in only 1-8% of patients admitted to hospitals, but in around 10% of patients housed in intensive care units where it can represent up to 15% of all nosocomial infections. We review the epidemiology of invasive candidiasis in non-immunocompromised, critically ill patients with special emphasis on disease trends over time, pathophysiology, diagnostic approach, risk factors, and impact. Recent epidemiological data suggesting that the emergence of non-albicans candida strains with reduced susceptibility to azoles, previously linked to the use of new antifungals for empiric and prophylactic therapy in immunocompromised patients, may not have occurred in the critically ill. Management of invasive candidiasis in these patients will be addressed in the December issue of The Lancet Infectious Diseases.

Candiduria in critically ill patients admitted to intensive care medical units

BACKGROUND

The purpose of this study was to determine the incidence of candiduria in critically ill patients admitted to intensive care medical units (ICUs), to identify risk factors for candiduria and to assess the frequency distribution of different Candidaspp.

SUBJECTS AND METHODS

This was a prospective cohort observational and multicenter study. A total of 1,765 patients older than 18 years of age who were admitted for at least 7 days to 73 medical-surgical ICUs of 70 Spanish hospitals were included in the study. Urine cultures were performed once a week.

RESULTS

In 389 patients (22%), Candidaspp. in one or more urine samples were isolated. In the multivariate analysis, independent risk factors for candiduria included: age >65 years, female sex, length of hospital stay before ICU admission, diabetes mellitus, total parenteral nutrition, mechanical ventilation and previous use of antimicrobials. Candida albicanswas recovered in 266 cases (68.4%), followed by C. glabrata(32 cases, 8.2%) and C. tropicalis(14 cases, 36%). Previous use of antifungal agents was the only risk factor for the selection of Candidanon-albicans candiduria (OR 2.64, 95% CI 1.35-5.14, P=0.004). In-hospital mortality was 48.8% in patients with candiduria compared to 36.6% in those without candiduria ( P<0.001). Significant differences were also found for ICU mortality (38.% vs. 28.1%, P<0.001).

CONCLUSIONS

Twenty-two percent of critically ill patients admitted for more than 7 days in the ICU developed candiduria. C. albicanswas the most frequent causative pathogen. Previous use of antifungals was the only risk factor for the selection of Candidanon-albicans.