Evaluation of laboratory markers of sepsis screen in the diagnosis of early onset neonatal septicemia

Abstract

Background: In the absence of accessibility to more recent, sophisticated techniques for early detection of neonatal sepsis, most neonatal health care facilities are forced to still rely on various routinely available hematological markers. However, reports on the diagnostic utility of these markers in the septic screen are rather conflicting. Aim of the study was to evaluate the diagnostic accuracy of routinely available laboratory markers of sepsis screen, and their combinations in diagnosis of early onset neonatal septicemia (EOS). Methods: This prospective, hospital based, cross-sectional study was performed in the Department of Pediatrics of two Tertiary Care Teaching Hospitals, North India. The study involved term neonates admitted with either suspected EOS/ risk factors for sepsis in neonatal ICU, post-natal ward, or the pediatric ward. Control group comprised apparently healthy neonates without risk factors for sepsis. Blood cultures and sepsis screen were performed in all babies at enrollment. Results: The study group included 161 babies. Of these, 56 (34.78%) were blood culture positive. Control group comprised 102 neonates. Sepsis screen was positive in 69.57% subjects with clinically suspected sepsis, 83.93% cases of true sepsis, and 54.92% controls. Sensitivity, specificity, positive predictive value and negative predictive value of sepsis screen were 83.93%, 35.29%, 41.59% and 80.00%, respectively. Amongst individual markers of sepsis screen, CRP had best diagnostic utility with highest sensitivity (82.14%), specificity (89.22%), PPV (80.70%), NPV (90.10%), and LR+ (7.62), and the lowest LR- (0.20). The combination of CRP plus I/T had the highest sensitivity (78.57%), specificity (100%), PPV (100%) and NPV (89.47%), and the lowest LR- (0.21) amongst all other 2 marker combinations. Conclusions: Combination of CRP plus I/T can serve as a reliable and useful tool for rapid diagnosis of EOS in term neonates. However, all other two test combinations do not have requisite high sensitivity, specificity and negative predictive value.