Etminan-Bakhsh Mina, Tadi Sima, Darabi Roksana
M.D Gynecologist, Associate Professor, Department of Obstetrics and Gynecology, Islamic Azad University, Tehran Medical Sciences Branch, Tehran, Iran.
Electron Physician. 2017 Nov 25;9(11):5760-5763. doi: 10.19082/5760. eCollection 2017 Nov.
Asymptomatic bacteriuria is one of the common problems in pregnancy. Asymptomatic bacteriuria is associated with pyelonephritis, preterm labor and low birth weight infants. The physiological and anatomical changes in pregnancy facilitate urinary tract infection (UTI) during pregnancy. Several tests are available for diagnosis of asymptomatic bacteriuria. The urine culture is a gold standard diagnostic test for asymptomatic bacteriuria but it is expensive and time-consuming. Screening methods may be useful in detecting high-risk pregnant women for asymptomatic bacteriuria.
The aim of the present study was to compare urine analysis as a rapid screening test to urine culture in diagnosis of asymptomatic bacteriuria.
A total of 123 pregnant women attending the obstetrics clinic of Boo-Ali hospital in Tehran, Iran from March 2013 to September 2014 were included in the present diagnostic cross-sectional study. One hundred twenty three mid-stream urine samples were inoculated into cultures and were processed by dipstick (nitrite test and leucocyte esterase test) and microscopic pus cell count. The sensitivity, specificity, positive predictive value and negative predictive value of nitrite test, leucocyte esterase test and microscopic pus cell count were compared with urine culture in diagnosis of asymptomatic bacteriuria by using SPSS version 19.
Of 123 urine samples, significant asymptomatic bacteriuria (≥10 cfu/Ml) was detected in 8 (6.5%) subjects. The sensitivity and specificity of nitrite test were 37% and 100% respectively. The sensitivity of pus cell count alone and leucocyte esterase test alone were 100% but the specificity of them were 64% and 65% respectively. We found high negative predictive value by Pus cell count and the leucocyte esterase test (100%) and low positive predictive value by them (16% and 17% respectively).
Urine culture is the most useful test for diagnosis of asymptomatic bacteriuria. None of our screening tests had a sensitivity and specificity of 100%, whereas we can only refer the pregnant women with positive leucocyte esterase test and significant pyuria to the urine culture.
无症状菌尿是孕期常见问题之一。无症状菌尿与肾盂肾炎、早产及低体重儿有关。孕期的生理和解剖学变化易导致孕期尿路感染（UTI）。有多种检查可用于诊断无症状菌尿。尿培养是无症状菌尿的金标准诊断检查，但费用高且耗时。筛查方法可能有助于检测无症状菌尿的高危孕妇。
本研究旨在比较尿液分析作为快速筛查试验与尿培养在诊断无症状菌尿中的效果。
本诊断性横断面研究纳入了2013年3月至2014年9月在伊朗德黑兰布阿里医院产科门诊就诊的123名孕妇。将123份中段尿样本接种于培养基中，并采用试纸条法（亚硝酸盐试验和白细胞酯酶试验）及显微镜下脓细胞计数进行处理。使用SPSS 19版软件比较亚硝酸盐试验、白细胞酯酶试验及显微镜下脓细胞计数在诊断无症状菌尿时相对于尿培养的敏感性、特异性、阳性预测值和阴性预测值。
在123份尿样本中，8名（6.5%）受试者检测出显著无症状菌尿（≥10 cfu/Ml）。亚硝酸盐试验的敏感性和特异性分别为37%和100%。单纯脓细胞计数和单纯白细胞酯酶试验的敏感性均为100%，但特异性分别为64%和65%。我们发现脓细胞计数和白细胞酯酶试验的阴性预测值较高（100%），而阳性预测值较低（分别为16%和17%）。
尿培养是诊断无症状菌尿最有用的检查。我们的筛查试验均未达到100%的敏感性和特异性，而我们只能将白细胞酯酶试验阳性且脓尿显著的孕妇送去做尿培养。
