Acute phase reactants in neonatal bacterial infection.

The C-reactive protein (CRP) level was evaluated in 142 infants requiring investigation for suspected infection. After excluding two neonates because of incomplete data, there remained 140 neonates, of whom 16 had septicemia. Fifteen of 16 had increased CRP levels. The CRP value was not elevated in any baby (n = 5) who had positive blood cultures for Staphylococcus epidermidis, all of whom had an uneventful clinical course. The CRP level was elevated in all six babies with meconium-aspiration syndrome, but was normal in five infants whose viral cultures were positive. Ninety-nine percent of uninfected babies had normal CRP values. Overall, CRP was a valuable test for diagnostic confirmation of bacterial infection. Elevated CRP level was always accompanied by at least one abnormality in the other tests performed. Although the study was not intended to predict clinical onset of bacterial disease, our results suggest that the CRP level, because of a high negative predictive value, may be useful in ruling out bacterial infection.