Tecnológico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Programa Multicéntrico de Neonatología, ITESM y Cátedra de Terapia Celular, Ave. Ignacio Morones Prieto 3000 poniente, Edificio CITES, tercer piso, oficina 307, Col. Doctores, CP 64710, Monterrey, Nuevo León, Mexico.
Int J Infect Dis. 2013 Feb;17(2):e110-4. doi: 10.1016/j.ijid.2012.09.005. Epub 2012 Oct 29.
To study the potential of buffy coat culture as a diagnostic tool for neonatal late-onset sepsis.
This was a study of diagnostic accuracy in newborn infants born at 28-41 weeks of gestation, weighing >800g, with ≥8 points on the NOSEP-1 scale. Paired samples for total blood culture (TBC) and buffy coat culture were drawn. We established the positivity rate, sensitivity, specificity, predictive values, and likelihood ratios, and compared time to positivity and contamination rates.
Fifty-two newborns were included in the study. Twenty-one TBC and 22 buffy coat cultures were positive. The positivity rate for TBC was 40.4% and for buffy coat culture was 42.3% (p=not significant). Three TBC were positive with negative buffy coat culture. Four buffy coat cultures were positive with negative TBC; Kappa agreement was 0.723, p <0.001. Buffy coat culture sensitivity was 86% (95% confidence interval (CI) 68.5-95.4%), specificity 87% (75.4-93.7%), positive predictive value 82% (65.4-91.1%), negative predictive value 90% (77.9-96.8%), positive likelihood ratio 6.64 (2.79-15.05), and negative likelihood ratio 0.16 (0.05-0.42). We found no difference in time to positivity in hours; Wilcoxon Z=1224, p=0.22. The contamination rate was 1.9% for both methods.
Buffy coat culture is as good as TBC for the microbiological diagnosis of late-onset sepsis of the newborn. Buffy coat culture allows the use of remaining plasma for further analysis.
研究血涂片培养作为诊断晚发性新生儿败血症的工具的潜力。
这是一项对 28-41 周、体重 >800g、NOSEP-1 评分为≥8 分的新生儿的诊断准确性研究。对总血培养（TBC）和血涂片培养进行配对样本采集。我们确定了阳性率、敏感性、特异性、预测值和似然比，并比较了阳性时间和污染率。
研究纳入了 52 名新生儿。21 份 TBC 和 22 份血涂片培养阳性。TBC 的阳性率为 40.4%，血涂片培养的阳性率为 42.3%（p=无显著差异）。3 份 TBC 阳性而血涂片培养阴性。4 份血涂片培养阳性而 TBC 阴性；Kappa 一致性为 0.723，p<0.001。血涂片培养的敏感性为 86%（95%置信区间（CI）为 68.5-95.4%），特异性为 87%（75.4-93.7%），阳性预测值为 82%（65.4-91.1%），阴性预测值为 90%（77.9-96.8%），阳性似然比为 6.64（2.79-15.05），阴性似然比为 0.16（0.05-0.42）。我们没有发现两种方法在阳性时间上有差异；Wilcoxon Z=1224，p=0.22。两种方法的污染率均为 1.9%。
血涂片培养与 TBC 一样，可用于新生儿晚发性败血症的微生物学诊断。血涂片培养可使剩余血浆用于进一步分析。
