1. A method of detecting a disease agent in a patient sample, the method comprising: generating, using an IR spectrometer, a sample infra-red spectrum representative of the patient sample without drying the sample, the sample spectrum having one or more spectral components, each component having a wavenumber and absorbance value; subtracting a corresponding water blank intensity value from the absorbance value for the wavenumber of each component, wherein the water blank intensity value is measured using the IR spectrometer; providing a computer with a reference database of spectral models, each model having one or more database spectral components of a wavenumber and an absorbance value, wherein the database spectral components identify disease agents; using the computer to determine whether the reference database has one or more database spectral components corresponding to one or more sample spectral components; compiling and depicting a list of corresponding database components identified on a display screen.