Our study provides evidence that age ≥ 6 months but ≤2 years, apyrexy and CRP ≤ 100 mg/L was a better model to distinguish K. kingae SA from classic pathogens in children <5 years, with an overall PPV of 86.7%, 88.6% for K. kingae and 83.9% for pyogenic infections. The gene discussed is CRP; the disease is infection.