The Effect of Experimental Typhus Fever on B. Typhosus and Pneumococcus Agglutinins

Abstract

Abstract The Weil-Felix reaction or the presence of agglutinins for B. proteus X19 in the blood is of great value in the diagnosis of typhus fever. Except in clinical (1) and experimental (2) Rocky Mountain spotted fever this reaction rarely occurs during other febrile diseases (3) (4). On the other hand, the presence or appearance of the Widal reaction, or agglutinins for typhoid bacilli in the serum is a common occurrence during typhus fever. During typhus, the Widal reaction may appear alone or together with the Weil-Felix reaction and is often stronger and increases in titer more rapidly than the Weil-Felix reaction, thus often giving rise to confusion in making early diagnoses. The temperature curve of a case of undoubted typhus fever in which both reactions were encountered is illustrated in figure 1. This patient had been immunized with typhoid and paratyphoid A and B vaccine one year prior to his illness.