Diagnostic methods and devices

A diffraction-based diagnostic method for differentiating the causes of a respiratory infection in a human comprising:

• providing a fluidic sample from a human;
• providing a test device comprising a first discrete test site and a second discrete test site wherein the first discrete test site comprises a first binder that is selected to bind to a first analyte selected from any of groups (i)-(v):
• group (i) a bacteria or a substance produced by a human in response to a bacterial infection, group (ii) a virus or a substance produced by a human in response to a viral infection, group (iii) a fungi or a substance produced by a human in response to a fungal infection, group (iv) a protozoa or a substance produced by a human in response to a protozoan infection and group (v) an allergen or a substance produced by a human in response to an allergic reaction, and the second discrete test comprises a second binder that binds a second analyte and wherein the second analyte is different than the first analyte;
• introducing the sample to the device wherein at least a portion of the sample contacts the first test site and the second test site;
• directing light at the first test site and the second test site;
• and
• evaluating light reflected from or transmitted through the first test site for diffraction indicating that binding has occurred at the first test site and evaluating light reflected from or transmitted through the second test site for a change indicating that binding has occurred at the second test site.

A device for determining the cause of a malady in an animal comprising:

• a test device comprising discrete first and second test sites and wherein said first and second test sites are integral to said test device,
• said first test site comprises a first binder that to binds to an analyte selected from the group consisting of bacteria, substances produced by an animal in response to a bacterial infection, viruses, substances produced by an animal in response to a viral infection, fungi, substances produced by an animal in response to a fungal infection, protozoa, substances produced by an animal in response to a protozoan infection, allergens and substances produced by a animal in response to an allergic reaction;
• and
• said second test site comprises a second binder that binds to a different analyte than the first binder.