Abstract
Recently, the complement fixation reaction in typhus fever, first studied by Castaneda, 1 has been refined so that not only typhus may be differentiated from other rickettsial diseases such as Rocky Mountain Spotted Fever, 2 but may itself be classified according to epidemic or murine nature. 3 Inasmuch as we have been interested in the etiology of typhus fever in this area, and have reached certain tentative conclusions based on the studies of the biology of the rickettsia strains locally isolated, 4 we wish now to use the complement fixation test to complete our studies. Unfortunately so far, owing to the scarcity of clinical cases seen in the past year, the number of sera examined has been small. But the results seem to be sufficiently consistent to warrant a preliminary report at this time.
Method and results. The antigens used in the present study, kindly supplied by the Lederle Laboratory Division of the American Cyanamid Company, 5 consist of washed rickettsial bodies. The method of complement fixation test is that of Kolmer's modified by reducing all ingredients to one-half the volume of the regular method. Sera were obtained from patients suffering from clinical typhus fever 6 some of which have been preserved by the lyophile process. Any serum showing anticomplementary action was treated by the method of Faran. 7 It was found that all except one gave positive reaction to both antigens, with titres mostly above 1:320, and one reaching as high as 1:20,480. Among these, 5 sera showed the same titre for both antigens, while 14 sera from 10 patients showed a higher titre to the epidemic antigen: 4 with a 2-fold difference, 4 with 4-fold difference, 5 with 8-fold difference and one positive only to epidemic antigen at titre 1:640.
Get full access to this article
View all access options for this article.