Methods and devices for accurate diagnosis of infections

Abstract

Diagnostic devices test markers for viral infection and markers for bacterial infection to effectively assist in the rapid differentiation of viral and bacterial infections, to differentiate between colonization and active infection, and to better diagnose microbiologically unconfirmed patients. In other embodiments, detecting a presence of MxA in combination with either the bacterial biomarker C-reactive protein or the bacterial biomarker procalcitonin increases the specificity of the bacterial biomarker with a concurrent improvement in sensitivity.

What is claimed is: 
     
         1 . A method for determining whether an infection is bacterial and/or viral using an immunoassay, comprising the step of:
 determining a presence of MxA through detection of mRNA of MxA in a sample, and   determining at least a first threshold concentration of mRNA of C-reactive protein in the sample.   
     
     
         2 . The method of  claim 1 , further comprising determining a second threshold concentration of mRNA of C-reactive protein higher than the first threshold concentration of mRNA of C-reactive protein in the sample. 
     
     
         3 . The method of  claim 1 , wherein the immunoassay is an Enzyme Linked Fluorescent assay (ELFA). 
     
     
         4 . The method of  claim 1 , wherein the immunoassay is a multiparametric immunoassay. 
     
     
         5 . The method of  claim 1 , wherein the immunoassay is a through polymerase chain reaction. 
     
     
         6 . The method of  claim 1 , further comprising determining a presence of mRNA of procalcitonin. 
     
     
         7 . The method of  claim 2 , wherein the presence of at least an approximately equivalent number of copies of mRNA equivalent to 25 ng/ml MxA protein in the sample confirms a viral infection; the presence of at least an approximately equivalent number of copies of mRNA equivalent to a concentration of 15 mg/L of C-reactive protein is indicative of the first threshold concentration of C-reactive protein or the presence of an equivalent number of copies of mRNA equivalent to at least 0.10 ng/ml of procalcitonin in the sample confirms a bacterial infection; and the presence of at least an approximately equivalent number of copies of mRNA equivalent to a concentration of 80 mg/L of C-reactive protein indicative of the second threshold concentration of C-reactive protein in the sample indicates a severe bacterial infection. 
     
     
         8 . The method of  claim 1 , wherein the detection of the mRNA of MxA is determined by measuring an amount of upregulated by type I alpha/beta or type II interferons. 
     
     
         9 . A kit for diagnosing whether an infection is bacterial and/or viral, comprising at least one reagent for determining a presence of mRNA of MxA in a sample and determining a presence of a first threshold concentration of mRNA of C-reactive protein in a sample, at least one reagent determining a presence of a second threshold concentration of mRNA of C-reactive protein that is higher than the first threshold concentration of mRNA of C-reactive protein in the sample. 
     
     
         10 . The kit of  claim 9 , the reagent that determines the presence of mRNA of MxA elicits a positive MxA result if at least an approximately an equivalent number of copies of mRNA equivalent to 25 ng/ml of mRNA of MxA protein is present in the sample;
 the reagent that determines the presence of the first threshold concentration of mRNA of C-reactive protein elicits a positive low C-reactive protein result if at least an approximately equivalent number of copies of mRNA equivalent to 20 mg/L of mRNA of C-reactive protein is present in the sample; and   the reagent that determines the presence of the second threshold concentration of mRNA of C-reactive protein elicits a positive high C-reactive protein result if at least an approximately equivalent number of copies of mRNA equivalent to 80 mg/L of mRNA of C-reactive protein is present in the sample.   
     
     
         11 . The kit of  claim 10 , further comprising a reagent that determines the presence of mRNA of procalcitonin elicits a positive procalcitonin result if at least an approximately equivalent number of copies of mRNA equivalent to 0.15 ng/ml of mRNA of procalcitonin is present in the sample. 
     
     
         12 . A method for determining whether an infection is bacterial and/or viral using an immunoassay, comprising the step of:
 determining a presence of MxA in a sample through precursors of MxA selected from a group consisting of: type 1 alpha interferons, type 1 beta interferons and type II interferons; and   determining at least a first threshold concentration of mRNA of C-reactive protein in the sample.   
     
     
         13 . The method of  claim 12 , further comprising determining a second threshold concentration of mRNA of C-reactive protein higher than the first threshold concentration of mRNA of C-reactive protein in the sample. 
     
     
         14 . The method of  claim 12 , wherein the immunoassay is an Enzyme Linked Fluorescent assay (ELFA). 
     
     
         15 . The method of  claim 12 , wherein the immunoassay is a multiparametric immunoassay. 
     
     
         16 . The method of  claim 12 , further comprising determining a presence of mRNA of procalcitonin. 
     
     
         17 . The method of  claim 13 , wherein the presence of at least an approximately equivalent number of copies of mRNA equivalent to 25 ng/ml or mRNA of MxA protein in the sample confirms a viral infection; the presence of at least an approximately equivalent number of copies of mRNA equivalent to a concentration of 15 mg/L of mRNA of C-reactive protein indicative of the first threshold concentration of mRNA of C-reactive protein or the presence of at least an equivalent number of copies of mRNA equivalent to 0.10 ng/ml of procalcitonin in the sample confirms a bacterial infection; and the presence of at least approximately equivalent number of copies of mRNA equivalent to a concentration of 80 mg/L of mRNA of C-reactive protein indicative of the second threshold concentration of C-reactive protein in the sample indicates a severe bacterial infection. 
     
     
         18 . A kit for diagnosing whether an infection is bacterial and/or viral, comprising: at least one reagent for determining a presence of MxA in a sample through precursors of MxA selected from a group consisting of: type 1 alpha interferons, type 1 beta interferons and type II interferons in a sample and determining a presence of a first threshold concentration of mRNA of C-reactive protein in a sample; at least one reagent determining a presence of a second threshold concentration of mRNA of C-reactive protein that is higher than the first threshold concentration of mRNA of C-reactive protein in the sample. 
     
     
         19 . The kit of  claim 18 , the reagent that determines the presence of precursors of MxA elicits a positive MxA result if at least an approximately equivalent number of copies of mRNA equivalent to 25 ng/ml MxA protein is present in the sample;
 the reagent that determines the presence of the first threshold concentration of C-reactive protein elicits a positive low C-reactive protein result if at least an approximately equivalent number of copies of mRNA equivalent to 20 mg/L of C-reactive protein is present in the sample; and   the reagent that determines the presence of the second threshold concentration of C-reactive protein elicits a positive high C-reactive protein result if at least an approximately equivalent number of copies of mRNA equivalent to 80 mg/L of C-reactive protein is present in the sample.   
     
     
         20 . The kit of  claim 18 , further comprising a reagent that determines the presence of procalcitonin elicits a positive procalcitonin result if at least an approximately equivalent number of copies of mRNA equivalent to 0.15 ng/ml of procalcitonin is present in the sample. 
     
     
         21 . The method of  claim 18 , wherein the presence of MxA to at least an approximately equivalent number of copies of mRNA equivalent to 20 ng/ml MxA protein in the sample confirms a viral infection; the presence of mRNA equivalent to at least an approximately equivalent number of copies of mRNA equivalent to a concentration of 15 mg/L of C-reactive protein indicative of the first threshold concentration of C-reactive protein or the presence of mRNA to procalcitonin equivalent to at least an equivalent number of copies of mRNA equivalent to 0.10 ng/ml of procalcitonin in the sample confirms a bacterial infection; and the presence of at least an approximately equivalent number of copies of mRNA equivalent to a concentration of mRNA to at least 80 mg/L of C-reactive protein indicative of the second threshold concentration of C-reactive protein in the sample indicates a severe bacterial infection.