Improved Methods and Devices for Accurate Diagnosis of Infections

摘要

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.

主权项

1. A method of screening a patient with a respiratory infection for bacterial colonization, comprising the steps of:
a) performing a first test for a presence of bacteria; b) if the first test indicates bacteria is present, performing a second test to quantitatively determine a level of procalcitonin or C-reactive protein in a patient sample; wherein a patient sample testing positive for atypical bacteria using PCR in the first test and a level of procalcitonin in a patient sample less than 0.1 ng/ml or a level of C-reactive protein in the patient sample is less than 20 mg/l indicates negative for infection; wherein a cell culture result of greater than 1×106 CFU/ml atypical bacteria in the first test and a level of procalcitonin less than 0.15 ng/ml indicates colonization; wherein a cell culture result of greater than 1×106 CFU/ml atypical bacteria in the first test, a level of procalcitonin greater than or equal to 0.15 ng/ml and less than 0.25 ng/ml, a white blood cell count less than 12,000, and no bands indicates colonization; wherein a cell culture result of greater than 1×106 CFU/ml atypical bacteria in the first test and a level of C-reactive protein less than 20 mg/l indicates colonization; wherein a cell culture result of greater than 1×106 CFU/ml atypical bacteria in the first test, a level of C-reactive protein greater than or equal to 20 mg/l and less than 80 mg/l, a white blood cell count less than 12,000, and no bands indicates colonization; and c) if the patient tests positive for Strep A or Strep C using cell culture and a level of procalcitonin is less than 0.1 ng/ml or a level of C-reactive protein is less than 20 mg/l, testing for Streptolysin O antibody and a white blood cell count; wherein a Streptolysin O antibody of less than 80% and a white blood cell count of less than 12,000 indicates colonization; and wherein negative paired serology indicates colonization.