Stimulation of B. typhosus Agglutinin in Typhus Fever.

Abstract

It has long been recognized that the agglutinin for typhoid bacilli as shown by the Widal reaction is often encountered during typhus fever. In our experience here we observe that the sera obtained from proved cases of typhus may show early Widal test up to a higher titre while the Weil-Felix reaction or the presence of agglutinin for B. proteus X19 may appear later or in a much lower titre. Some of these cases may give the history either of previous typhoid infection or prophylactic vaccination, but in others none of these factors could be definitely ascertained. It has been suggested by some observers that during typhus fever the appearance of the Widal reaction is due to non-specific stimulation of latent or low titre antibodies by the fever. 1

In a recent observation, however, it has been found that experimental typhus in animals (guinea pigs, rabbits and monkeys), previously vaccinated with typhoid bacilli, had no influence on the Widal reaction. 2 This is contradictory to actual findings made in human beings. In view of the value of B. proteus X19 as an antigen for the diagnosis of typhus fever, it seems to us of interest to determine whether the introduction of that organism into typhoid inoculated animals would stimulate the production of anti-typhoid agglutinin.

In our present experiment we are not concerned with the action of other microorganisms in this direction, since non-specific stimulation of specific antibodies has been recorded on experimental animals through the use of certain heterologous bacteria 3 that have no relation whatsoever with typhus fever.