Clinical value of CRP, PCT, SAA in identifying bacterial infections with viral infections

Objective To evaluate the clinical value of serum amyloid A (SAA), high-sensitivity C-reactive protein (hs-CRP) and serum procalcitonin (PCT) in identifying patients with bacterial infections with viral infections. Methods A total of 326 hospitalized patients in hospital were included. The patients were divided into viral infection group (n=68), bacterial infection group (n=182), virus and bacterial mixed infection group (n=11), fungal infection group (n=6) and non-infected group (n=59). The levels of SAA, hs-CRP and PCT were detected and compared. The receiver operating characteristic curve (ROC) was used to evaluate the diagnostic value of each index. Logistic regression model was used to evaluate the influence index of diagnostic efficacy of each index. Results There were significant differences in SAA, hs-CRP and PCT among the groups (all P<0.05). Compared with other groups, the PCT level in the bacterial infection group was significantly higher (P<0.05). The levels of SAA and hs-CRP in the mixed group were significantly higher (P<0.05). The diagnostic accuracy of SAA, hs-CRP and PCT indicators for viral infection was relatively low, and was high for bacterial infection. It had certain clinical value for the diagnosis of mixed infection of viruses and bacteria. The results of logistic regression analysis showed that the PCT index had the maximum partial regression coefficient, and the PCT diagnosis of bacteria and virus infection had the greatest diagnostic efficiency. Conclusions Clinicians can combine the SAA, hs-CRP and PCT indicators in the diagnosis process, which can significantly improve the accuracy of the diagnosis of infectious diseases. Key words: Amyloid A; High-sensitivity C-reactive protein; Procalcitonin; Bacteria; Virus; Infection; Diagnosis