定量未离心尿液显微镜检查、尿试纸条白细胞酯酶和亚硝酸盐检测在快速诊断尿路感染中的有效性。

Validity of quantitative unspun urine microscopy, dipstick test leucocyte esterase and nitrite tests in rapidly diagnosing urinary tract infections.

作者信息

Taneja N, Chatterjee S S, Singh M, Sivapriya S, Sharma M, Sharma S K

机构信息

Department of Medical Microbiology, PGIMER, Chandigarh.

出版信息

J Assoc Physicians India. 2010 Aug;58:485-7.

PMID:21189695

Abstract

OBJECTIVES

Rapid diagnostic tests can screen out negative samples and can save valuable time and money. The study was conducted to assess the usefulness of leukocyte esterase, nitrate reductase and quantitative microscopic unspun urine wet mount examination in rapidly diagnosing urinary tract infections (UTI).

METHODS

Four hundred and fifty samples were tested by semi-quantitative culture on cysteine lactose electrolyte deficient medium, microscopic examination of unspun urine for significant pyuria, dipstick leucocyte esterase test (LET) and nitrite test (NT). Culture was used as gold standard to evaluate the performance of direct microscopy and dipstick tests.

RESULTS

Urine culture examination revealed significant bacteriuria (>10(5) cfu/ml) 98 (21.8%), in urine samples. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and the diagnostic odds ratio (DOR) of the dip-stick LET were 73.5%, 58.5%, 33.0%, 88.8%, and 3.9 respectively; those of the dip-stick NT were 57.1%, 78.7%, 42.7%, 86.8%, and 4.9 respectively; and those for microscopic significant pyuria detection were 68.4%, 60.8%, 32.7%, 87.3%, and 3.4 respectively. Highest sensitivity (95.9%), NPV (97.9%) and DOR (25.7) was obtained on combining microscopy and dip-stick LET and NT (either of them positive). This can potentially cut costs by 79%.

CONCLUSION

Quantitative unspun urine wet mount microscopy and dipstick tests for leucocyte esterase and nitrite test should be added into routine laboratory practices for faster diagnosis of UTI.

摘要

目的

快速诊断检测可筛选出阴性样本，节省宝贵的时间和金钱。本研究旨在评估白细胞酯酶、硝酸盐还原酶及定量显微镜未离心尿液湿片检查在快速诊断尿路感染（UTI）中的作用。

方法

采用半定量培养法在半胱氨酸乳糖电解质缺乏培养基上对450份样本进行检测，同时进行未离心尿液的显微镜检查以检测显著脓尿，采用尿试纸白细胞酯酶试验（LET）和亚硝酸盐试验（NT）。以培养结果作为金标准来评估直接显微镜检查和尿试纸检测的性能。

结果

尿液培养检查显示，98份（21.8%）尿液样本存在显著菌尿（>10⁵ cfu/ml）。尿试纸LET的敏感性、特异性、阳性预测值（PPV）。阴性预测值（NPV）和诊断比值比（DOR）分别为73.5%、58.5%、33.0%、88.8%和3.9；尿试纸NT的上述指标分别为57.1%、78.7%、42.7%、86.8%和4.9；显微镜检查显著脓尿的上述指标分别为68.4%、60.8%、32.7%、87.3%和3.4。将显微镜检查与尿试纸LET和NT联合使用（二者其一为阳性）时，获得了最高敏感性（95.9%）、NPV（97.9%）和DOR（25.7）。这有可能降低79%的成本。