C-reactive protein differentiates RSV from bacterial infection

Higdon MM, Le T, O’Brien KL, Murdoch DR, Prosperi C, Baggett HC, Brooks WA, Feikin DR, Hammitt LL, Howie SRC, Kotloff KL, Levine OS, Scott JAG, Thea DM, Awori JO, Baillie VL, Cascio S, Chuananon S, DeLuca AN, Driscoll AJ, Ebruke BE, Endtz HP, Kaewpan A, Kahn G, Karani A, Karron RA, Moore DP, Park DE, Rahman MZ, Salaudeen R, Seidenberg P, Somwe SW, Sylla M, Tapia MD, Zeger SL, Knoll MD, Madhi SA; for the PERCH Study Group. Association of C-Reactive Protein with Bacterial and Respiratory Syncytial Virus–Associated Pneumonia Among Children Aged <5 Years in the PERCH Study. Clinical Infectious Diseases. 2017 Jun 15; Suppl 3(64): S378-386. Available from: doi: 10.1093/cid/cix150.


As part of the Pneumonia Etiology Research in Child Health (PERCH) multi centre case control study, Higdon and colleagues evaluated the sensitivity and specificity of C-reactive protein (CRP) for differentiating RSV and bacterial pneumonia. The comparison groups included “confirmed” bacterial pneumonia (positive blood / pleural fluid culture; or positive lung aspirate or PCR) and PCR confirmed RSV pneumonia. They observed that elevated CRP was positively associated with confirmed bacterial pneumonia and negatively associated with RSV pneumonia, with a sensitivity (77%) and specificity (82%) at a cut-point of 37.1 mg/L. They suggest that CRP could be useful to distinguish bacterial from RSV pneumonia. However, it was acknowledged that the cut-point varied by demographic and clinical factors, and might not be representative of other settings or other respiratory viral-associated pneumonia. Therefore, CRP should be complemented with other pathogen specific diagnostic tools to increase the performance.

Full Article on PubMed.