A systematic review including 16 studies with a total of 2219 subjects was abstracted in DARE. Due to heterogeneity of studies no meta-analysis was attempted. The leukocyte count and ratios had a wide range of sensitivity (17 - 90%) and specificity (31 - 100%). Measuring CRP qualitatively showed sensitivity results of 44 - 92% and specificity of 42 - 93%). Measuring CRP quantitatively showed sensitivity results of 58 - 100% (5 of the studies recordied sensitivities of 100%) and a specificity of 68 - 94%.