Differentiating between bacterial and viral infections by estimated CRP velocity

Michal Largman-Chalamish, Asaf Wasserman, Adi Silberman, Tal Levinson, Omri Ritter, Shlomo Berliner, David Zeltser, Itzhak Shapira, Ori Rogowski, Shani Shenhar-Tsarfaty*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Purpose Differentiating between acute viral and bacterial infection is challenging due to the similarity in symptom presentation. Blood tests can assist in the diagnosis, but they reflect the immediate status and fail to consider the dynamics of an inflammatory response with time since symptom onset. We applied estimated C-reactive protein (CRP) velocity (eCRPv), as derived from the admission CRP level divided by time from symptom onset, in order to better distinguish between viral and bacterial infections. Methods This cross-sectional study included patients admitted to the emergency department with a confirmed viral (n = 83) or bacterial (n = 181) infection. eCRPv was defined as the ratio between the absolute CRP level upon admission to time from symptom onset (in hours). Absolute CRP and eCRPv values were compared between the 3 groups. Results Bacterial patients presented with higher CRP levels (133 mg/L) upon admission compared to viral patients (23.31 mg/L) (P < 0.001). Their median value of eCRPv velocity was 4 times higher compared to the viral patients (1.1 mg/L/h compared 0.25 mg/L/h, P < 0.001). Moreover, in intermediate values of CRP (100–150 mg/L) upon admission, in which the differential diagnosis is controversial, high eCRPv is indicative of bacterial infection, eCRPv >4 mg/ L/h represents only bacterial patients. Conclusions During an acute febrile illness, the eCRPv value can be used for rapid differentiation between bacterial and viral infection, especially in patients with high CRP values. This capability can potentially expedite the provision of appropriate therapeutic management. Further research and validation may open new applications of the kinetics of inflammation for rapid diagnosis of an infectious vs. a viral source of fever.

Original languageEnglish
Article numbere0277401
JournalPLoS ONE
Issue number12 December
StatePublished - Dec 2022
Externally publishedYes


FundersFunder number
Dalia and Arie PrashkovskyTLV2021-345


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