CRP and pertussis: The mean length of hospital stay (11.5 ± 4.9 days versus 6.9 ± 5.2 days, p < 0.001), C-reactive protein (CRP) levels (29 ± 7.5 mg/L versus 9 ± 3.6 mg/L, p < 0.001), and white blood cell (WBC) count (31.2 ± 9.7 × 109/L versus 18.2 ± 6.3 × 109/L, p < 0.001) were significantly higher in the pertussis group compared to the control group.