ABSTRACT
Abstract Background: Urinary tract infection (UTI) is infants´ most common serious bacterial infection. This study aimed to investigate the reliability of urianalysis (UA) to predict UTI, to specify the colony forming units (CFU)/ml threshold for diagnosis, and to identify variables that help suspect bacteremia in infants under 3 months with UTI. Methods: We reviewed clinical records of children under 3 months hospitalized for a fever without source and recorded age, sex, days of fever pre-consultation, temperature and severity at admission, discharge diagnoses, laboratory tests, and treatments. According to the discharge diagnosis, we divided them into UTIs (-) and (+) with or without bacteremia. Results: A total of 467 infants were admitted: 334 with UTI and 133 without UTI. In UTIs (+), the pyuria had a sensitivity of 95.8% and bacteria (+) 88.3%; specificity was high, especially for nitrites (96.2%) and bacteria (+) (92.5%). Positive predictive value (PPV) for nitrites was 95.9%, for bacteria 96.7%, and oyuria 92.5%. Escherichia coli was present in 83.8% of urine and 87% of blood cultures. UTIs with bacteremia had inflammatory urinalysis, urine culture > 100,000 CFU/ml, and higher percentage of C reactive protein (CRP) > 50 mg (p= 0.002); 94.6% of the urine culture had > 50,000 CFU. Conclusions: The pyuria and bacteria (+) in urine obtained by catheterization predict UTI. The cut-off point for diagnosis was ≥ 50,000 CFU/ml. No variables to suspect bacteremia were identified in this study.
Resumen Introducción: La infección del tracto urinario (ITU) es una infección bacteriana grave frecuente en lactantes. El objetivo de este trabajo fue investigar la fiabilidad del análisis de orina (AO) para predecirla, precisar el umbral de unidades formadoras de colonias (UFC)/ml para el diagnóstico y buscar variables que ayuden a sospechar de bacteriemia en lactantes menores de 3 meses con ITU. Métodos: Se revisaron fichas clínicas de lactantes menores de 3 meses hospitalizados por fiebre sin foco evidente, registrando edad, sexo, días de fiebre preconsulta, temperatura y gravedad al ingreso, diagnósticos de egreso, exámenes de laboratorio y tratamientos. Según diagnóstico de egreso, se separaron en ITU (-) y (+), con o sin bacteriemia. Resultados: Ingresaron 467 lactantes: 334 con ITU y 133 sin ITU. En ITU (+), la sensibilidad de la piuria fue de 95.8% y bacterias (+) 88.3%; la especificidad fue alta para nitritos (96.2%) y bacterias (+) (92.5%). El valor predictivo positivo (VPP) fue de 95.9% para nitritos, 96.7% para bacterias y 92.5% para piuria. Escherichia coli se encontró en el 83.8% de los urocultivos (UC) (+) y en el 87% de los hemocultivos (+). Las ITU con bacteriemia presentaron elementos inflamatorios, UC con ≥ 100,000 UFC/ml y mayor porcentaje de proteína C reactiva (PCR) > 50 mg/l (p= 0.002); el 94.6% de los UC (+) tuvo ≥ 50,000 UFC/ml. Conclusiones: La piuria y bacterias (+) en el AO son excelentes para pronosticar ITU en orina obtenida con sonda vesical y el punto de corte para el diagnóstico debe ser ≥ 50,000 UFC/ml. No encontramos señales que ayudaran a sospechar ITU con bacteriemia.
ABSTRACT
PURPOSE: Catheter urine (CATH-U) and suprapubic aspiration (SPA) are reliable urine collection methods for confirming urinary tract infections (UTI) in infants. However, noninvasive and easily accessible collecting bag urine (CBU) is widely used, despite its high contamination rate. This study investigated the validity of CBU cultures for diagnosing UTIs, using CATH-U culture results as the gold standard. METHODS: We retrospectively analyzed 210 infants, 2- to 24-month-old, who presented to a tertiary care hospital's pediatrics department between September 2008 and August 2013. We reviewed the results of CBU and CATH-U cultures from the same infants. RESULTS: CBU results, relative to CATH-U culture results (> or =104 colony-forming units [CFU]/mL) were widely variable, ranging from no growth to > or =105 CFU/mL. A CBU cutoff value of > or =105 CFU/mL resulted in false-positive and false-negative rates of 18% and 24%, respectively. The probability of a UTI increased when the CBU bacterial count was > or =105/mL for all infants, both uncircumcised male infants and female infants (likelihood ratios [LRs], 4.16, 4.11, and 4.11, respectively). UTIs could not be excluded for female infants with a CBU bacterial density of 104-105 (LR, 1.40). The LRs for predicting UTIs based on a positive dipstick test and a positive urinalysis were 4.19 and 3.11, respectively. CONCLUSION: The validity of obtaining urine sample from a sterile bag remains questionable. Inconclusive culture results from CBU should be confirmed with a more reliable method.
Subject(s)
Child, Preschool , Female , Humans , Infant , Male , Bacterial Load , Catheters , Matched-Pair Analysis , Pediatrics , Retrospective Studies , Stem Cells , Tertiary Healthcare , Urinalysis , Urinary Tract Infections , Urine Specimen CollectionABSTRACT
PURPOSE: To examine the usefulness of simple and quick criteria for identifying febrile infants younger than 90 days with a low risk for serious bacterial infection (SBI). METHODS: We conducted a retrospective study of febrile infants younger than 90 days who visited an emergency department (ED) between July 2010 and June 2011. We reviewed their medical history, physical examination findings, levels of white blood cells (WBC) and C-reactive protein (CRP), blood culture, urinalysis, and an analysis of their cerebrospinal fluid (CSF). Patients who met all the following criteria were considered to have a low risk for SBI: (1) an unremarkable medical history, (2) a good appearance, (3) no focal physical signs of infection, (4) WBC 5,000~15,000 /mm3, (5) CRP <2.0 mg/dL, (6) a normal urinalysis, and (7) CSF WBC <25 /mm3 for neonate or <10 /mm3 for infants between 29 days and 90 days. SBI was defined as a positive culture of bacteria from blood, cerebrospinal fluid, or urine. RESULTS: Complete data were available for 493 infants. SBI was documented in 62(12.6%) infants, with 54(11.0%) having a urinary tract infection, 3(0.6%) with bacteremia, 1 (0.2%) with bacterial meningitis, and 4(0.8%) with co-infections. The sensitivity and negative predictive value for SBI from the combination of low-risk criteria was 98.4% and 99.6%, respectively. CONCLUSION: Although low-risk infants must be carefully observed, our criteria for low-risk might be a reliable and useful tool for excluding SBI for febrile young infants in ED.
Subject(s)
Humans , Infant , Infant, Newborn , Bacteremia , Bacteria , Bacterial Infections , C-Reactive Protein , Coinfection , Emergencies , Leukocytes , Meningitis, Bacterial , Physical Examination , Retrospective Studies , Urinalysis , Urinary Tract InfectionsABSTRACT
PURPOSE: To characterize the infants under 3 months of age with urinary tract infections(UTIs), and especially patients with bacteremia or meningitis METHODS: Hospital records of all the infants under 3 months of age discharged from our hospital for 69 consecutive months with the diagnosis of initial episode of UTI were reviewed. UTI was defined when patients had fever with pyuria, and had urine culture results of > or = 10(5) colony forming units/mL from a bag specimen. Patients with previously known urologic abnormality or immunodeficiency were excluded. Nosocomial infections were also excluded from the study. RESULTS: The male:female ratio was 35 : 6. Of the urine cultures, 40(97.6%) yielded single pathogen, one yielded two pathogens. Escherichia coli was the predominant isolate from the urine. Five patients(12%) also had bacteremia. Pathogens isolated from the blood cultures were E. coli(4) and Enterococcus faecalis(1). No patient had culture-positive meningitis or cerebrospinal fluid pleocytosis. Clinical or laboratory findings between patients with and without bacteremia were not different significantly. The rate of vesicoureteral reflux(VUR) was 44%. The sensitivity of ultrasound for detection of VUR was 38%; specificity was 50%. CONCLUSION: Clinical and laboratory data were not helpful for identifying patients with bacteremia at the time of presentation. Consequently, blood cultures need to be obtained from all febrile infants under 3 months of age with UTIs. A large-scale study including the indication of lumbar puncture for infants with a febrile UTI and study of evaluation and treatment of infants under 3 months of age with UTIs are required.