Febrile urinary tract infection in the emergency room. Curr Opin Infect Dis. 2015;28:106-111. [PMID: 25402776 DOI: 10.1097/qco.0000000000000121]

Evaluation of the sysmex UF-5000 fluorescence flow cytometer as a screening platform for ruling out urinary tract infections in elderly patients presenting at the Emergency Department

In this study, we evaluated the performance of the flow cytometer-based Sysmex UF-5000 automated urine analyzer as a screening tool for ruling out urinary tract infections in elderly patients presenting at the emergency department. A total of 1119 unselected patient samples (including 544 samples from elderly patients) submitted for urine culture were included in this study. Samples were measured on UF-5000 and dipsticks and the results were compared with interpretation of culture results, which is the gold standard. We obtained a diagnostic sensitivity of 99% and specificity of 51% with a low rate of false negatives (0.2%) and a negative predictive value of 99% at 10⁸ colony forming bacteria/L (CFB/L). A bacterial count ≥ 50x10⁶/L or yeast like cells ≥ 25x10⁶/L was used as the cutoff value. At this cutoff value, 30% of the urine cultures would have been redundant. This resulted in 35% false positive samples, mainly due to particle contamination or nongrowing bacteria. In comparison, at best, the dipsticks have a diagnostic sensitivity of 89%, a specificity of 52% and a negative predictive value of 92% at 10⁸ CFB/L.

A diagnostic algorithm for detection of urinary tract infections in hospitalized patients with bacteriuria: The "Triple F" approach supported by Procalcitonin and paired blood and urine cultures

For acute medicine physicians, distinguishing between asymptomatic bacteriuria (ABU) and clinically relevant urinary tract infections (UTI) is challenging, resulting in overtreatment of ABU and under-recognition of urinary-source bacteraemia without genitourinary symptoms (USB). We conducted a retrospective analysis of ED encounters in a university hospital between October 2013 and September 2018 who met the following inclusion criteria: Suspected UTI with simultaneous collection of paired urinary cultures and blood cultures (PUB) and determination of Procalcitonin (PCT). We sought to develop a simple algorithm based on clinical signs and PCT for the management of suspected UTI. Individual patient presentations were retrospectively evaluated by a clinical "triple F" algorithm (F1 ="fever", F2 ="failure", F3 ="focus") supported by PCT and PUB. We identified 183 ED patients meeting the inclusion criteria. We introduced the term UTI with systemic involvement (SUTI) with three degrees of diagnostic certainty: bacteremic UTI (24.0%; 44/183), probable SUTI (14.2%; 26/183) and possible SUTI (27.9%; 51/183). In bacteremic UTI, half of patients (54.5%; 24/44) presented without genitourinary symptoms. Discordant bacteraemia was diagnosed in 16 patients (24.6% of all bacteremic patients). An alternative focus was identified in 67 patients, five patients presented with S. aureus bacteremia. 62 patients were diagnosed with possible UTI (n = 20) or ABU (n = 42). Using the proposed "triple F" algorithm, dichotomised PCT of < 0.25 pg/ml had a negative predictive value of 88.7% and 96.2% for bacteraemia und accordant bacteraemia respectively. The application of the algorithm to our cohort could have resulted in 33.3% reduction of BCs. Using the diagnostic categories "possible" or "probable" SUTI as a trigger for initiation of antimicrobial treatment would have reduced or streamlined antimicrobial use in 30.6% and 58.5% of cases, respectively. In conclusion, the "3F" algorithm supported by PCT and PUB is a promising diagnostic and antimicrobial stewardship tool.

Performance of the cobas u 701 Analyzer in Urinary Tract Infection Screening

Background

Negative urine cultures to rule out urinary tract infections (UTI) generate a considerable laboratory workload; thus, a rapid screening test is desirable. We evaluated the performance of a new automated microscopy analyzer, cobas u 701 (Roche Diagnostics International, Rotkreuz, Switzerland) for the screening of UTI, and developed a rule-out strategy to reduce the number of samples requiring culture. We also assessed squamous epithelial cell (SEC) count as a predictor of culture contamination.

Methods

In total, 1,604 urine samples from outpatients were analyzed with cobas u 701 and culture. Bacterial (BAC) and white blood cell (WBC) counts were used for sample interpretation. To determine a useful cut-off point to predict negative cultures, we selected the highest sensitivity and specificity values obtained from ROC curves. Diagnostic accuracy by age and gender was evaluated.

Results

Urine culture showed growth of ≥10⁴ colony forming units (CFU)/mL in 256 samples (16.0%). The highest sensitivity (91.8%) and specificity (68.4%) were obtained for cut-off points of 119 BAC/µL and 22 WBC/µL. The combination of BAC and WBC improved the performance of the rule-out strategy with a low rate of false-negative results (1.5%) and a high negative predictive value (NPV, 97.3%). Fifty-seven percent of the samples would not have required culture. SEC count was a poor predictor of culture contamination.

Conclusions

cobas u 701 can substantially reduce the number of urine samples requiring culture, with a low false-negative rate and a high NPV.

[Infections in critically ill patients]

Introducción

Las infecciones son muy frecuentes en los pacientes que se encuentran ingresados en los servicios de medicina intensiva, siendo unas veces motivo de ingreso y en otras la infección se adquiere durante el ingreso.

Epidemiologia

Las causas más frecuentes de infección adquirida en la comunidad que precisa ingreso en la UCI son las infecciones respiratorias, infecciones urinarias y las infecciones del sistema nervioso central. Dentro de las infecciones adquiridas en la UCI, las asociadas a dispositivos son las más frecuentes.

Etiología

Los gérmenes más frecuentes en la UCI son los Gram negativos.

Etiopatogenia. En el paciente crítico se aúnan factores, haciéndolos especialmente vulnerables a las infecciones.

Manifestaciones clínicas

Dependerán de la localización de la infección.

Diagnóstico

Debe ser precoz dada su alta mortalidad.

Pronóstico

Las infecciones nosocomiales se asocian con un aumento de la mortalidad y la estancia.

Tratamiento

El retraso en el tratamiento se asocia con un aumento de la mortalidad.

Utility of initial procalcitonin values to predict urinary tract infection

BACKGROUND

Urinary tract infections (UTIs) are one of the most common reasons women seek treatment in the emergency department (ED). The biomarker procalcitonin (PCT) has gained popularity over the last decade to improve the diagnosis of bacterial infections and reduce unnecessary exposure to antibiotics. PCT has been extensively studied in patients with pneumonia and sepsis and may have additional role in UTI.

METHODS

A retrospective study of patients who presented to the ED in which a urinalysis test and a PCT level was obtained within the first 24h of presentation. Signs and symptoms of UTI and urine cultures were reviewed to determine a positive diagnosis of UTI. The area under the receiver operating curve was used to calculate the test characteristics of PCT. Different breakpoints were analyzed to determine which PCT level corresponded to the highest sensitivity and specificity.

RESULTS

293 patients were included in this single center, retrospective study. The AUC of PCT to predict UTI was 0.717; 95% CI: 0.643-0.791 (p<0.001). A PCT threshold of 0.25ng/ml corresponded to the best combination of sensitivity (67%) and specificity (63%), with a positive predictive value and negative predictive value of 26% and 91%, respectively.

CONCLUSIONS

A PCT threshold <0.25ng/ml was a strong predictor of the absence of UTI. The high negative predictive value of PCT may be useful as an adjunct to urinalysis results to rule out UTI and facilitate noninitiation or earlier discontinuation of empiric antibiotics.

Evaluation of the Cobas u 701 microscopy analyser compared with urine culture in screening for urinary tract infection

Purpose. A new automated Cobas u 701 microscopy analyser for urine sediment examination was introduced. The aim of this study was to evaluate the analyser in comparison with urine culture in screening for urinary tract infection (UTI).Methodology. A total of 852 urine specimens submitted for culture were included in this study. Urine sediment examination was performed using the Cobas u 701 microscopy analyser. The results of the bacteria (BAC) and yeast (YEA) analyses were compared with the results from urine culture as a method for UTI screening. In addition, we compared the BAC results with white blood cells (WBCs) and leukocyte and nitrite measurement in the Cobas u 601 system.Results. Of the 852 urine specimens, 16.1 % (N=137) were positive by urine culture, yielding 130 bacteria from 124 specimens and 14 yeasts from 14 specimens. The Cobas u 701 microscopy analyser provided no result for 52 specimens because of their high turbidity. The sensitivity, specificity, positive predictive value and negative predictive value were 85.8, 69.4, 33.1 and 96.5 %, respectively. For YEA, these figures were 100, 91.9, 15.8 and 100 %, respectively. The areas under the curve for BAC and WBCs were 0.827 [95 % confidence interval (CI) 0.799, 0.852] and 0.727 (95 % CI 0.695, 0.757), respectively. The sensitivity of the leukocyte and nitrite was 63.5 and 54.6 %, respectively.Conclusion. The Cobas u 701 microscopy analyser showed good diagnostic performance. It can be used for rapid screening for UTI and can reduce the number of cultures required.

Febrile urinary tract infections: pyelonephritis and urosepsis

PURPOSE OF REVIEW

Complicated infections of the urinary tract (UTI) including pyelonephritis and urosepsis are also called febrile UTI. This review describes insights from the literature on this topic since July 2014.

RECENT FINDINGS

Recent studies regarding risk factors and consequences of febrile UTI confirmed existing knowledge. It remains difficult to obtain insight into the epidemiology of febrile UTI because urine and blood cultures are frequently missing. The relationship between host and virulence factors of Escherichia coli was further explored showing that less virulent strains can cause infection in immunocompromised patients. In contrast to obstructive uropathy, diabetes, and being older, neutropenia was not a risk factor for lower UTI or urosepsis. A randomized controlled trial revealed that ceftolozane-tazobactam was marginally superior to levofloxacin as treatment for complicated UTI. Case series supported the notion that xanthogranulomatous and emphysematous pyelonephritis are more common in diabetic patients and that drainage or surgery is often required.

SUMMARY

Neutropenia was not a risk factor for lower UTI or urosepsis. When local resistance percentages to the frequently prescribed fluoroquinolones are high, the combination of ceftolozane-tazobactam may be an alternative as treatment for complicated UTI. Xanthogranulomatous and emphysematous pyelonephritis need to be considered in diabetic patients presenting with UTI symptoms.

Comparison of computed tomography findings between bacteremic and non-bacteremic acute pyelonephritis due to Escherichia coli

AIM: To identify computed tomography (CT) findings that are associated with the presence of bacteremia in patients with acute pyelonephritis (APN) due to Escherichia coli (E. coli).

METHODS: The clinical data and contrast-enhanced CT findings of 128 patients who were diagnosed with APN due to E. coli and showed renal abnormality on contrast-enhanced CT between January 2003 and November 2013 were retrospectively reviewed. The patients were divided into two groups according to the presence of bacteremia: The bacteremia group and the non-bacteremia group. The abnormality on contrast-enhanced CT were categorized into 5 renal and 4 extrarenal CT findings and compared between the two groups using the χ² test and multivariate logistic regression.

RESULTS: Among the 128 patients, 34 patients (26.6%) were classified into the bacteremia group and 94 patients (73.4%) into the non-bacteremia group. There was no statistically significant difference in gender between the two groups (P = 0.09), but the age of the patients in the bacteremia group was higher than that of the patients in the non-bacteremia group (P < 0.01). Compared to the non-bacteremia group, 1 renal CT finding such as urothelial thickening and 3 extrarenal CT findings such as diffuse peritoneal thickening, cystitis and pulmonary congestion were more frequently observed in the bacteremia group with statistical significance. The logistic regression analysis revealed that CT findings, including urothelial thickening, diffuse peritoneal thickening, cystitis and pulmonary congestion were suggested as the predictive CT findings of bacteremic APN.

CONCLUSION: On CT, urothelial thickening, diffuse peritoneal thickening, cystitis, and pulmonary congestion are more frequently observed in patients with bacteremic APN due to E. coli.

Infectious Disease-Related Emergency Department Visits of Elderly Adults in the United States, 2011-2012

OBJECTIVES

To investigate the frequency of infectious disease (ID)-related emergency department (ED) visits of elderly adults in the United States.

DESIGN

Cross-sectional analysis.

SETTING

Nationwide emergency department sample in 2011-12.

PARTICIPANTS

Individuals in the ED aged 65 and older with a primary diagnosis of an ID.

MEASUREMENTS

ID-related ED visits, hospitalizations, hospital-based mortality.

RESULTS

During 2012, a weighted estimate of 3,123,909 ED visits for IDs was calculated in elderly U.S. adults. This accounted for 13.5% (3.1 million visits) of all ED visits of elderly adults; this burden was higher than that for myocardial infarction and congestive heart failure combined. The rate of ID-related ED visits was 7,231 per 100,000 elderly adults. The most-common diagnoses were lower respiratory infections (26.2%; 95% confidence interval (CI)=25.7-26.6%), urinary tract infections (25.3%, 95% CI=25.0-25.7%), and septicemia (18.9%, 95% CI=18.3-19.6%). Of all ID-related ED visits, 1,786,657 (57.2%, 95% CI=56.6-57.7%) resulted in hospitalization. The leading cause of hospitalization was septicemia, accounting for 32.2% (95% CI=31.1-33.3%) of all ID-related hospitalizations through EDs, followed by lower respiratory infections (27.8%, 95% CI=27.2-28.4%). Overall, 123,894 individuals (4.0%, 95% CI=3.8-4.1%) died during their ED visit or hospitalization. Of these, septicemia was the leading cause of mortality (74.7%, 95% CI=73.8-75.6%), followed by lower respiratory infections (15.2%, 95% CI=14.6-15.9%). Analysis of the 2011 data gave similar results for the burden of ID-related ED visits, hospitalizations, and mortality.

CONCLUSION

Using a nationally representative sample, it was found that the public health burden of IDs in elderly U.S. adults was substantial, as measured by ED visits, subsequent hospitalizations, and hospital-based mortality.

Procalcitonin and pyuria-based algorithm reduces antibiotic use in urinary tract infections: a randomized controlled trial

BACKGROUND

Urinary tract infections (UTIs) are common drivers of antibiotic use. The minimal effective duration of antibiotic therapy for UTIs is unknown, but any reduction is important to diminish selection pressure for antibiotic resistance, costs, and drug-related side-effects. The aim of this study was to investigate whether an algorithm based on procalcitonin (PCT) and quantitative pyuria reduces antibiotic exposure.

METHODS

From April 2012 to March 2014, we conducted a factorial design randomized controlled open-label trial. Immunocompetent adults with community-acquired non-catheter-related UTI were enrolled in the emergency department of a tertiary-care 600-bed hospital in northwestern Switzerland. Clinical presentation was used to guide initiation and duration of antibiotic therapy according to current guidelines (control group) or with a PCT-pyuria-based algorithm (PCT-pyuria group). The primary endpoint was overall antibiotic exposure within 90 days. Secondary endpoints included duration of the initial antibiotic therapy, persistent infection 7 days after end of therapy and 30 days after enrollment, recurrence and rehospitalizations within 90 days.

RESULTS

Overall, 394 patients were screened, 228 met predefined exclusion criteria, 30 declined to participate, and 11 were not eligible. Of these, 125 (76% women) were enrolled in the intention-to-treat (ITT) analysis and 96 patients with microbiologically confirmed UTI constituted the per protocol group; 84 of 125 (67%) patients had a febrile UTI, 28 (22%) had bacteremia, 5 (4%) died, and 3 (2%) were lost to follow-up. Overall antibiotic exposure within 90 days was shorter in the PCT-pyuria group than in the control group (median 7.0 [IQR, 5.0-14.0] vs. 10.0 [IQR, 7.0-16.0] days, P = 0.011) in the ITT analysis. Mortality, rates of persistent infections, recurrences, and rehospitalizations were not different.

CONCLUSIONS

A PCT-pyuria-based algorithm reduced antibiotic exposure by 30% when compared to current guidelines without apparent negative effects on clinical outcomes.