Lo Denise Swei, Rodrigues Larissa, Koch Vera Hermina Kalika, Gilio Alfredo Elias
Universidade de São Paulo, Hospital Universitário, Departamento de Pediatria, São Paulo, SP, Brasil.
Universidade de São Paulo, Faculdade de Medicina, Instituto da Criança, Departamento de Pediatria, São Paulo, SP, Brasil.
J Bras Nefrol. 2018 Jan-Mar;40(1):66-72. doi: 10.1590/1678-4685-JBN-3602. Epub 2018 Apr 26.
Urinary tract infection (UTI) is the most common serious bacterial infection in young infants. Signs and symptoms are often nonspecific.
To describe clinical, demographic and laboratory features of UTI in infants ≤ 3 months old.
Cross-sectional study of infants ≤ 3 months old with UTI diagnosed in a pediatric emergency department, for the period 2010-2012. UTI was defined as ≥ 50,000 colony-forming units per milliliter of a single uropathogen isolated from bladder catheterization. Paired urinalysis and urine culture from group culture-positive and group culture-negative were used to determine the sensitivity and specificity of pyuria and nitrite tests in detecting UTI.
Of 519 urine cultures collected, UTI was diagnosed in 65 cases (prevalence: 12.5%); with male predominance (77%). The most common etiologies were Escherichia coli (56.9%), Klebsiella pneumoniae (18.5%) and Enterococcus faecalis (7.7%). Frequent clinical manifestations were fever (77.8%), irritability (41.4%) and vomiting (25.4%). The median temperature was 38.7°C. The sensitivity of the nitrite test was 30.8% (95%CI:19.9-43.4%), specificity of 100% (95%CI:99.2-100%). Pyuria ≥ 10,000/mL had a sensitivity of 87.7% (95%CI:77.2-94.5%), specificity of 74.9% (95%CI:70.6 -78.8%). The median peripheral white blood cell count was 13,150/mm3; C-reactive protein levels were normal in 30.5% of cases.
The male: female ratio for urinary tract infection was 3.3:1. Non-Escherichia coli etiologies should be considered in empirical treatment. Fever was the main symptom. Positive nitrite is highly suggestive of UTI but has low sensitivity; whereas pyuria ≥ 10,000/mL revealed good sensitivity, but low specificity. Peripheral white blood cell count and C-reactive protein concentration have limited usefulness to suggest UTI.
尿路感染（UTI）是婴幼儿中最常见的严重细菌感染。其体征和症状往往不具有特异性。
描述3个月及以下婴儿尿路感染的临床、人口统计学和实验室特征。
对2010年至2012年期间在儿科急诊科诊断为尿路感染的3个月及以下婴儿进行横断面研究。尿路感染的定义为从膀胱导尿中分离出的单一尿路病原体每毫升≥50,000菌落形成单位。对培养阳性组和培养阴性组进行配对尿液分析和尿培养，以确定脓尿和亚硝酸盐试验在检测尿路感染中的敏感性和特异性。
在收集的519份尿培养样本中，65例被诊断为尿路感染（患病率：12.5%）；男性居多（77%）。最常见的病因是大肠埃希菌（56.9%）、肺炎克雷伯菌（18.5%）和粪肠球菌（7.7%）。常见的临床表现为发热（77.8%）、烦躁（41.4%）和呕吐（25.4%）。中位体温为38.7°C。亚硝酸盐试验的敏感性为30.8%（95%CI：19.9 - 43.4%），特异性为100%（95%CI：99.2 - 100%）。脓尿≥10,000/mL的敏感性为87.7%（95%CI：77.2 - 94.5%），特异性为74.9%（95%CI：70.6 - 78.8%）。外周血白细胞计数中位数为13,150/mm3；30.5%的病例C反应蛋白水平正常。
尿路感染的男女比例为3.3:1。经验性治疗时应考虑非大肠埃希菌病因。发热是主要症状。亚硝酸盐阳性高度提示尿路感染，但敏感性低；而脓尿≥10,000/mL显示出良好的敏感性，但特异性低。外周血白细胞计数和C反应蛋白浓度对提示尿路感染的作用有限。
