From the Division of Emergency Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA.
Pediatr Emerg Care. 2020 Oct;36(10):481-485. doi: 10.1097/PEC.0000000000001344.
Screening for urinary tract infection (UTI) includes urinary nitrite testing by dipstick urinalysis. Gram-negative enteric organisms produce urinary nitrite and represent the most common uropathogens. Enterococcus, a less common uropathogen, does not produce nitrite and has a unique antibiotic resistance pattern. Whether to adjust empiric antibiotics in the absence of urinary nitrite has not been established. Our primary objective was to determine prevalence of enterococcal UTI among young children with a nitrite negative urinalysis.
A retrospective study of children aged less than 2 years evaluated in the emergency department for possible UTI and had a paired urinalysis and urine culture was performed. Urinary tract infection was defined by catheterized culture yielding greater than or equal to 50,000 colony-forming units per milliliter of a single uropathogen. Prevalence of uropathogens among nitrite negative samples was studied.
A total of 7599 children were studied. Median (interquartile range) age was 5.6 (2.3-11.2) months, and 57% were female. Prevalence of UTI was 8.1%. Enterococcus was the uropathogen in 2.1% of UTIs, and all cases had negative dipstick nitrite. Among nitrite negative UTIs, 95.6% of uropathogens were gram-negative and only 3.2% (confidence interval, 1.8%-5.3%) were enterococcus. None of the 200 UTIs with positive nitrite yielded enterococcus (upper confidence interval, 1.4%). Among children with positive leukocyte esterase and negative nitrite, only 0.7% of cases had enterococcal UTI.
Only 3% of nitrite negative UTIs were caused by enterococcus. Given the low prevalence of enterococcal UTI, the absence of dipstick nitrite should not affect routine empiric antibiotic choice for presumptive UTI in young children.
尿路感染（UTI）的筛查包括尿试纸条分析的尿硝酸盐检测。革兰氏阴性肠道病原体产生尿液硝酸盐，是最常见的尿路病原体。肠球菌是一种不太常见的尿路病原体，它不产生硝酸盐，具有独特的抗生素耐药模式。在没有尿液硝酸盐的情况下是否调整经验性抗生素尚未确定。我们的主要目的是确定在硝酸盐阴性尿液分析的幼儿中肠球菌 UTI 的患病率。
对在急诊科评估可能患有 UTI 的年龄小于 2 岁的儿童进行回顾性研究，并进行了配对尿液分析和尿液培养。通过导管培养获得大于或等于 50,000 个菌落形成单位/毫升单一尿路病原体的 UTI 定义。研究了硝酸盐阴性样本中尿路病原体的患病率。
共研究了 7599 名儿童。中位数（四分位距）年龄为 5.6（2.3-11.2）个月，57%为女性。UTI 的患病率为 8.1%。肠球菌是 2.1%UTI 的病原体，所有病例的尿液试纸条硝酸盐均为阴性。在硝酸盐阴性 UTI 中，95.6%的病原体为革兰氏阴性菌，只有 3.2%（置信区间，1.8%-5.3%）为肠球菌。200 例硝酸盐阳性 UTI 中无一例产生肠球菌（上限置信区间，1.4%）。在白细胞酯酶阳性且硝酸盐阴性的儿童中，只有 0.7%的病例患有肠球菌 UTI。
只有 3%的硝酸盐阴性 UTI 是由肠球菌引起的。鉴于肠球菌 UTI 的患病率较低，在没有尿试纸条硝酸盐的情况下，不应对幼儿推定 UTI 的常规经验性抗生素选择产生影响。
