To evaluate various sepsis screening tests, individually and in combination, to formulate a guideline for the diagnosis of neonatal sepsis.

The study was a retrospective cohort study. It took place at the neonatal intensive care unit of the Paediatric Department, Il Sin Christian Hospital, Busan, Korea, over a period of 68 months from 1st, April, 2001 to 31st, December, 2005. This study evaluated 100 neonates having clinical features of sepsis and 100 normal asymptomatic neonates and used screening tests including C-reactive protein (CRP), total leukocyte count (TLC), absolute neutrophil count (ANC), immature neutrophils to total neutrophil count ratio (I/T ratio), thrombocytopenia, degenerative changes in the neutrophils and gastric aspirate cytology (GAC) for the diagnosis of neontal sepsis.

The sensitivity of CRP and ANC was high. CRP had 86 percent sensitivity for group-A (proven sepsis) and 74 percent sensitivity for group-B (probable sepsis) and 94 percent specificity for group-A, B. ANC had sensitivity of 72 percent for group-A and 62 percent for group-B and 86 percent specificity for group-A, B. For group-A, sensitivity, specificity of GAC for polymorphs was 74 percent and 94 percent respectively. As for sensitivity, specificity of platelet count for group-A was 64 percent and 89 percent respecively. The sensitivity, specificity and predictive values (PV) of the individual tests and different test combinations were also calculated for group-A and B.

For the detection of culture negative cases in neonatal sepsis, screening tests including CRP, TLC, ANC, thrombocytopenia, cytoplasmic vacuolization in the neutrophils and GAC for polymorphs have high sensitivity. A combination of three tests has higher sensitivity.