GP Clinics


Bacterial vs Viral Infections: Novel Assay Outperforms Existing Tests

A novel assay of integrated measurements of blood-borne host-proteins better distinguishes between viral and bacterial infections than C-reactive protein (CRP), procalcitonin, and routine laboratory parameters, according to a recent study.
Accurately distinguishing bacterial infections from viral ones can be difficult and often leads to antibiotic misuse.
For their study, the researchers assessed the serum remnants of children age 3 months to 18 years with (n = 529) and without (n = 68) suspicion of acute infection at 5 pediatric emergency departments and 2 wards. Children with a fever of 100.4° F or higher and had symptoms lasting 7 days or more were included in the infectious cohort.
Predetermined criteria and adjudication by experts blinded to the results of the assay were used to establish the reference standard diagnosis. Additionally, those who performed the assay were blinded to the reference standard. Assay cutoffs had been predefined.
A total of 100 of 529 patients with suspected acute infection did not fulfill the inclusion criteria for the infectious cohort, and 68 patients did not have sufficient serum. Therefore, 361 patients with 239 viral infections, 68 bacterial infections, and 54 indeterminate reference standard diagnoses were included in the present analysis. Results indicated that the assay had distinguished between viral and bacterial infections with 93.8% sensitivity and 89.8% specificity. The researchers noted that 11.7% of cases had an equivocal assay outcome.
Ultimately, the researchers found that the assay had outperformed CRP (cutoff 40 mg/L) and procalcitonin testing (cutoff 0.5 ng/mL).
“Double-blinded evaluation confirmed high assay performance in febrile children,” the researchers concluded. “Assay was significantly more accurate than CRP, procalcitonin, and routine laboratory parameters. Additional studies are warranted to support its potential to improve antimicrobial treatment decisions.”

Srugo I, Klein A, Stein M, et al. Validation of a novel assay to distinguish bacterial and viral infections. Pediatrics. 2017;140(4).