In a multivariate logistic-regression model, age greater than 65 years old (OR 1.78 (95%CI 1.15–2.74), p = 0.009), male gender (OR 1.58 (95%CI 1.10–2.28), p = 0.012), CRP ≥ 100 mg/L (OR 4.76 [95%CI 3.27–6.97], p < 0.001), and D-dimer count ≥ 1500 μg/L (OR 4.24 (95%CI 2.30–7.90), p < 0.001) were independently associated with infection severity. Here, CRP is linked to infection.