A persons body is subjected to the Weil-Felix test to identify rickettsial illnesses. A blood sample from the patient is used in an agglutination test to look for any illnesses. Through interactions between the antibodies, the test can identify the presence of anti-rickettsial antibodies. These antibodies are created during acute rickettsial infections that contain Proteus species OX antigens. The test can be performed using either the tube method or the slide method. The necessary antigens can be bought commercially.