Dutta Sourabh, Narang Anil, Chakraborty Anuradha, Ray Pallab
Department of Pediatrics, Postgraduate Institute of Medical Education and Research, Sector 12, Chandigarh 160012, India.
Arch Pediatr Adolesc Med. 2009 Jan;163(1):6-11. doi: 10.1001/archpediatrics.2008.513.
To study universal primer 16S rRNA gene polymerase chain reaction (PCR) for diagnosis of blood culture-positive neonatal sepsis before and after starting antibiotic drug therapy.
Prospective study of diagnostic tests.
Level III neonatal intensive care unit. Patients Neonates with a fresh episode of clinically suspected sepsis were enrolled; those with major malformations, life expectancy less than 12 hours, or contaminated blood cultures were excluded.
Before starting antibiotic drug therapy, PCR (0 hour), blood culture, and sepsis screening (complete blood cell counts, micro-erythrocyte sedimentation rate, and C-reactive protein level) were performed. The PCR was repeated 12, 24, and 48 hours after starting antibiotic drug therapy.
The primary outcomes were the sensitivity and specificity of 0-hour PCR for diagnosing blood culture-positive sepsis, and the secondary outcome was the proportion of 0-hour PCR-positive patients who remained positive after antibiotic drug therapy.
Of 306 patients evaluated, 242 were included (mean [SD] gestation, 32.2 [3.1] weeks; and mean [SD] birth weight, 1529.2 [597.2] g). Blood culture was positive in 52 patients and 0-hour PCR in 57. The sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of PCR were 96.2%, 96.3%, 87.7%, 98.8%, 26.1, and 0.04, respectively. Two patients were blood culture positive but 0-hour PCR negative, whereas 7 were 0-hour PCR positive but blood culture negative. Of the 0-hour PCR-positive patients, 7 remained positive at 12 hours and none at 24 and 48 hours after starting antibiotic drug therapy. In 0-hour PCR-positive patients, no predictors of positive 12-hour PCR were identified.
Universal primer PCR can accurately diagnose neonatal sepsis before but not after antibiotic drugs are given.
研究通用引物16S rRNA基因聚合酶链反应（PCR）在抗生素药物治疗前后对血培养阳性新生儿败血症的诊断价值。
诊断试验的前瞻性研究。
三级新生儿重症监护病房。患者纳入临床疑似败血症初发的新生儿；排除有严重畸形、预期寿命小于12小时或血培养污染的患者。
在开始抗生素药物治疗前，进行PCR（0小时）、血培养和败血症筛查（全血细胞计数、微量红细胞沉降率和C反应蛋白水平）。在开始抗生素药物治疗后12、24和48小时重复进行PCR。
主要结局是0小时PCR诊断血培养阳性败血症的敏感性和特异性，次要结局是抗生素药物治疗后0小时PCR阳性患者仍为阳性的比例。
在评估的306例患者中，242例被纳入研究（平均[标准差]孕周，32.2[3.1]周；平均[标准差]出生体重，1529.2[597.2]g）。52例患者血培养阳性，57例0小时PCR阳性。PCR的敏感性、特异性、阳性和阴性预测值以及阳性和阴性似然比分别为96.2%、96.3%、87.7%、98.8%、26.1和0.04。2例患者血培养阳性但0小时PCR阴性，7例0小时PCR阳性但血培养阴性。在0小时PCR阳性的患者中，7例在开始抗生素药物治疗后12小时仍为阳性，24和48小时均无阳性。在0小时PCR阳性的患者中，未发现12小时PCR阳性的预测因素。
通用引物PCR可在给予抗生素药物之前准确诊断新生儿败血症，但之后则不能。
