Objectives: To study the potential of buffy coat culture as a diagnostic tool for neonatal late-onset sepsis. Methods: This was a study of diagnostic accuracy in newborn infants born at 28-41 weeks of gestation, weighing >800. g, 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. Results: 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. Conclusions: 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.
Bibliographical noteFunding Information:
This work was supported in part by institutional funds from the Servicios de Salud del Estado de Nuevo León, assigned to Laboratorio Clínico, Hospital Metropolitano “Dr. Bernardo Sepúlveda”, Servicios de Salud del Estado de Nuevo León.
Copyright 2013 Elsevier B.V., All rights reserved.
All Science Journal Classification (ASJC) codes
- Microbiology (medical)
- Infectious Diseases