C-reactive protein in early detection of bacteremic versus viral infections in immunocompetent and compromised children.

The value of quantitatively determined C-reactive protein (CRP), measured from a finger prick sample for rapid detection of septicemia, was examined in 76 blood culture-positive infections in 54 immunocompetent and 18 compromised children; 73 patients with systemic viral infections served as controls. Development of a positive CRP reaction was also studied in 40 cases of acute epiglottitis. Beyond the neonatal age, an increased CRP value (greater than or equal to 20 mg/L) was found in 60 of 64 (94%) children with a positive blood culture for bacteria or fungus. By contrast, CRP remained below this value in 56 of 73 (77%) with viral infections. The immunologic status did not influence the CRP response. However, time had a highly significant (p less than 0.001) effect on CRP; a history of 6 to 12 hours of illness was required before CRP increased above normal. We conclude that CRP is a sensitive and rapidly reacting index in bacteremic infections. However, because other factors than septicemia also increase CRP, we deem a negative CRP value most informative; if two determinations taken several hours apart are less than 20 mg/L, the patient is very unlikely to have invasive bacterial infection.