Published online by Cambridge University Press: 15 May 2009
1. The Wilson-Weil-Felix agglutination reaction with cultures of Proteus “X 19” was Positive in dilutions of the serum ranging from 1 in 40 to 1 in 2560 in 22 out of 23 cases of Typhus Fever occurring in Ireland. In one case the reaction was still negative at the time of the patient's death on the 14th day of the disease. As controls, sera from the following gave completely negative results in a 1 in 20 dilution: 50 cases of Influenza, 12 cases of Trench Fever and 15 cases of Syphilis.
2. The agglutinins in Typhus serum for B. proteus “X 19” are completely destroyed by heating at 65° C. for half an hour.
3. Ten sera were tested for presence of immune body by means of the Complement Fixation test. The results were negative.
4. A coliform bacillus isolated from the urine of one case was agglutinated by the sera of twenty cases—the only ones examined—in dilutions varying from 1 in 40 to 1 in 640.
Sixty-two controls gave negative results with a 1 in 40 or higher dilution of their sera.
5. Absorption experiments indicated that the agglutinins for B. proteus “X 19” and this coliform bacillus were distinct.
6. The literature dealing with the heterologous agglutinins met with in the serum of Typhus Fever has been consulted and the various hypotheses that have been put forward to account for their presence have been examined. It is suggested that under the stimulus of infection with the Typhus Fever virus, some bacterium which is a normal inhabitant of the human intestine produces agglutinins for itself and group agglutinins for numerous other micro-organisms especially for Proteus “X 19,” Proteus “X 2,” and various members of the Colon-typhoid group.