Serological Varieties of Typhus Fever

Abstract

1. Fletcher and Lesslar's observations on two serological types of tropical typhus have been fully confirmed.2. The antigenic relationship between the indologenicB. proteusX 19 and the non-indologenic Kingsbury strain is of the same order as that obtaining between the X 19 and X 2 types ofB. proteusX.3. The Kingsbury strain is an antigenic variant derived from the original X 19 culture and represents another serological type ofB. proteusX. The symbol XK is suggested for this type.4. Sera from cases of classical European typhus and of endemic typhus of the United States of America and of Australia have been tested for the occurrence of main and group O agglutinins for the known types ofB. proteusX.5. H agglutination as source of error in the diagnosis of typhus cases is illustrated by some examples.6. Sera from cases of tsutsugamushi from Sumatra and Japan react with type XK like the Malayan cases of this disease described by Fletcher and co-workers.7. This latter reaction is of the order of group O agglutination. It is suggested that antigenically the virus of tsutsugamushi corresponds to another serological type ofB. proteusX which is yet unknown.8. The data published on the serum reactions in Rocky Mountain spotted fever and in the “fièvre exanthématique” of Marseilles are analysed. It is suggested that these two diseases represent further serological varieties of typhus.9. The significance hitherto attached to negative agglutination tests withB. proteusX and to negative cross-immunity tests obtained with some typhuslike diseases requires revision in the light of recent observations.