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

C-reactive protein measured in dried blood spots from patients with cystic fibrosis

There was no significant difference in C-reactive protein concentration determined in paired serum and eluates from dried blood spots collected on Guthrie cards; mean difference 0.6 microgram/ml (95% CI -3.3-2.2 micrograms/ml; n = 101). Dried blood spot samples were stable for up to 21 days and were unaffected by posting to the laboratory. In eight patients with cystic fibrosis undergoing specific antibiotic treatment for Pseudomonas aeruginosa pulmonary infection the fall in C-reactive protein concentration was not significantly different between serum and dried whole blood spot specimens. This method could be used to monitor infection and the response to antibiotic treatment.

Severity of childhood bacterial meningitis and duration of illness before diagnosis

Rapid diagnosis of childhood bacterial meningitis (BM) is generally believed to be essential to avoid poor outcome. To see whether duration of illness before admission to hospital was related to the severity of illness, data from children with BM diagnosed in 18 paediatric hospitals in Finland from 1984 to 1989 were collected prospectively. We divided 286 cases with culture-positive cerebrospinal fluid (CSF) into three groups: BM with a history of up to 24 h (short-history group, n = 141), of more than 24 h and up to 48 h (intermediate-history group, n = 75), and of more than 48 h (long-history group, n = 70). The longer the history, the better the clinical condition of the child. If symptoms or signs of BM lasted 48 h or less, the child did significantly worse, as judged by seven variables, than if the history was longer than 48 h (level of consciousness, p less than 0.001; seizures, p less than 0.01; CSF protein concentration, p less than 0.001; positive CSF gram-stain, p less than 0.01; positive blood culture, p less than 0.05 in Haemophilus influenzae meningitis; serum C-reactive protein, p less than 0.01 between intermediate-history and long-history groups; and urine sodium concentration, p less than 0.001). The differences were not affected by causative organism, sex, age, or preadmission oral antimicrobial agents. The findings show that if BM follows an insidious pattern of disease, diagnostic delay may be unavoidable, which may have medicolegal implications.

Neonatal Haemophilus influenzae infections

Nine cases of neonatal Haemophilus influenzae septicaemia were recorded in Finland during 1985-9; incidence was 2.8/100,000 live births, and 1.6% of all cases of neonatal septicaemia. The onset of the disease was early in all cases, ranging from 0-6 hours after delivery. Seven of the infants were preterm and three died (overall mortality 33%). H influenzae was isolated from blood in seven of the cases, and in two neonates with clinical signs of septicaemia it was found on several surface sites and the placenta. One of the eight strains of H influenzae was capsular type b and biotype I, the rest being non-typable--a distribution similar to those previously reported. Four of the uncapsulated strains were of biotype III, and three were of biotype II. None of the strains of H influenzae was of biotype IV, which has been reported to be characteristic of neonatal and genital isolates of H influenzae. All nine mothers had some sign of infection at the time of or shortly after delivery. H influenzae was isolated from five mothers: from the blood (n = 1) or from the placenta or cervix (n = 4). The use of intrauterine devices may be a possible risk factor for neonatal H influenzae infections; two of the mothers had such devices in place during their pregnancies.

C-reactive protein in the management of children with fever after allogeneic bone marrow transplantation

The value of C-reactive protein (CRP) determinations in the analysis of fever after allogeneic bone marrow transplantation (BMT) was studied prospectively by serial measurements of serum CRP levels during 30 BMT episodes in 28 children and adolescents. The treatments and procedures accompanying BMT did not elicit a significant CRP response. Forty-three febrile episodes were registered and analyzed, without previous knowledge of the results of CRP determinations. The incidence of bacterial infection and acute graft-versus-host disease (GvHD) was low, 8/30 and 5/30, respectively. Raised CRP levels occurred only once in association with GvHD. A CRP level higher than 50 mg/l was not sensitive as an indicator of bacterial infection (4/8). A CRP level below 50 mg/l in the presence of fever, however, excluded bacterial infection with a specificity of 86% and a negative predictive value of 88%. When timed properly and interpreted together with clinical and microbiological findings, CRP measurements can be a valuable aid in the management of fever after BMT, especially as a negative predictor.

Acute phase reactants and risk of bacterial meningitis among febrile infants and children

STUDY OBJECTIVE

To test the hypothesis that quantitation of either C-reactive protein (CRP) or the total peripheral WBC count can improve clinical detection of underlying bacterial meningitis among young febrile children.

DESIGN

Cross-sectional survey of selected symptoms of central nervous system infection, signs of meningeal irritation and/or elevated intracranial pressure, levels of CRP in serum, and total peripheral WBC counts among unselected pediatric patients undergoing lumbar punctures for evaluation of acute febrile illnesses.

SETTING

Emergency department and acute care "walk-in" clinic of an urban, university-affiliated general hospital.

PARTICIPANTS

160 previously well, acutely febrile infants and children (median age, 6 months).

RESULTS

The prevalence of bacterial meningitis was 6%. Sensitivity of symptoms was 1.00 and specificity was 0.17. Sensitivity of signs was 0.70 and specificity was 0.81. Of the acute phase reactants, sensitivity of a CRP level of more than 1.0 mg/dL was 0.80, while that of a total peripheral WBC count of more than 15,000/mm3 was 0.40. The presence of signs and/or a CRP level of more than 1.0 mg/dL correctly identified all children with bacterial meningitis (sensitivity, 1.00). The absence of signs and a CRP level of 1.0 mg/dL or less correctly identified 71 of 150 children without bacterial meningitis (specificity, 0.47). Of 125 children without meningeal signs, the combination of symptoms and a CRP level of more than 1.0 mg/dL correctly identified all three children with bacterial meningitis (sensitivity, 1.00). The absence of these symptoms and/or a CRP level of 1.0 mg/dL or less correctly identified 80 of 122 children without bacterial meningitis (specificity, 0.66).

CONCLUSION

Quantitation of CRP but not the total peripheral WBC count can increase the sensitivity of physical examination findings and the specificity of symptoms for the diagnosis of bacterial meningitis. Measurement of CRP in serum is useful as an adjunct to history and physical examination for the detection of acute bacterial meningitis in the acutely febrile child.

Potential clinical applications of C-reactive protein

This article reviews the clinical applications of C-reactive protein (CRP). This acute-phase protein is a distinct and sensitive marker for inflammation and tissue injury. It is a simple, fast, and relatively inexpensive latex agglutination test. The aspects of CRP reviewed include diagnostic support, serial measurements to evaluate disease course and therapeutic response, and screening studies.