The results showed that the body temperature, CRP, PCT, IL-6, IL-8, IL-10, TNF-β, and IFN-γ levels of patients with respiratory bacterial infection were 37.6°C, 20.80mg/L, 0.10 ng/mL, 41.67 pg/mL, 15.55 pg/mL, 8.02 pg/mL, 3.82 pg/mL, and 4.76 pg/mL, respectively.While, the levels of above indicators were found to be significantly lowered in patients without infection, i.e., 36.5°C, 4.37 mg/L, 0.04 ng/mL, 9.50 pg/mL, 6.61 pg/mL, 4.52 pg/mL, 2.96 pg/mL and 2.96 pg/mL, accordingly (P < 0.05) (Table 2 and Figures 1A–E and Supplementary Figures 1A–C). Here, CXCL8 is linked to infection.