An in vitro method for determining if an infection is bacterial or viral, comprising the steps of: a) collecting a blood sample; b) transferring the blood sample to a lateral flow chromatography test strip comprising: a reagent zone comprising: at least one first labeled binding partner that binds to C-reactive protein, such that, when C-reactive protein present in the blood sample contacts the first labeled binding partner, a first labeled complex forms; and at least one second labeled binding partner that binds to MxA, such that, when MxA present in the blood sample contacts the second labeled binding partner, a second labeled complex forms; wherein the first labeled binding partner comprises a first detectable label and the second labeled binding partner comprises a second detectable label, wherein the first detectable label has a first color and the second detectable label has a second color different than the first color; and a detection zone comprising: a third binding partner which binds to the first labeled complex and is immobilized on a first test line and a fourth binding partner which binds to the second labeled complex and is immobilized on the first test line or a second test line; c) lysing the blood sample on the lateral flow chromatographic test strip; d) eluting the lysed blood sample on the test strip; and e) analyzing the test strip for the presence of labelled C-reactive protein and/or MxA complexes in the detection zone. a) collecting a blood sample; b) transferring the blood sample to a lateral flow chromatography test strip comprising: a reagent zone comprising: at least one first labeled binding partner that binds to C-reactive protein, such that, when C-reactive protein present in the blood sample contacts the first labeled binding partner, a first labeled complex forms; and at least one second labeled binding partner that binds to MxA, such that, when MxA present in the blood sample contacts the second labeled binding partner, a second labeled complex forms; wherein the first labeled binding partner comprises a first detectable label and the second labeled binding partner comprises a second detectable label, wherein the first detectable label has a first color and the second detectable label has a second color different than the first color; and a detection zone comprising: a third binding partner which binds to the first labeled complex and is immobilized on a first test line and a fourth binding partner which binds to the second labeled complex and is immobilized on the first test line or a second test line; a reagent zone comprising: at least one first labeled binding partner that binds to C-reactive protein, such that, when C-reactive protein present in the blood sample contacts the first labeled binding partner, a first labeled complex forms; and at least one second labeled binding partner that binds to MxA, such that, when MxA present in the blood sample contacts the second labeled binding partner, a second labeled complex forms; wherein the first labeled binding partner comprises a first detectable label and the second labeled binding partner comprises a second detectable label, wherein the first detectable label has a first color and the second detectable label has a second color different than the first color; and at least one first labeled binding partner that binds to C-reactive protein, such that, when C-reactive protein present in the blood sample contacts the first labeled binding partner, a first labeled complex forms; and at least one second labeled binding partner that binds to MxA, such that, when MxA present in the blood sample contacts the second labeled binding partner, a second labeled complex forms; wherein the first labeled binding partner comprises a first detectable label and the second labeled binding partner comprises a second detectable label, wherein the first detectable label has a first color and the second detectable label has a second color different than the first color; and a detection zone comprising: a third binding partner which binds to the first labeled complex and is immobilized on a first test line and a fourth binding partner which binds to the second labeled complex and is immobilized on the first test line or a second test line; a third binding partner which binds to the first labeled complex and is immobilized on a first test line and a fourth binding partner which binds to the second labeled complex and is immobilized on the first test line or a second test line; c) lysing the blood sample on the lateral flow chromatographic test strip; d) eluting the lysed blood sample on the test strip; and e) analyzing the test strip for the presence of labelled C-reactive protein and/or MxA complexes in the detection zone.